FINAL MARINE SPECIALIST REPORT Marine …...cage culture operations (Algoa 1) Essential mitigation measures: Install and maintain suitable predator nets (sufficient strength, visibility

FINAL MARINE SPECIALIST REPORT

Marine aquaculture development zones for finfish

cage culture in the Eastern Cape:

Impact Assessment Report

Update July 2013

Prepared for:

Directorate Sustainable Aquaculture Management: Aquaculture Animal Health

and Environmental Interactions

Department of Agriculture, Forestry and Fisheries

User

Typewritten Text

Appendix B2

2

Executive Summary

An Environmental Impact Assessment (EIA) for the development of two marine aquaculture

development zones (ADZs) specific for finfish cage farming in the sea off the Eastern Cape Province is

being undertaken on behalf of the the Directorate Sustainable Aquaculture Management: Aquaculture

Animal Health and Environmental Interactions within the Department of Agriculture, Forestry and

Fisheries- DAFF. The DAFF mariculture policy aims to promote growth in the industry, as it envisions

benefits of skills-based job creation in poor coastal communities and increased seafood production to

compensate for dwindling catches of wild stocks.

The proposed ADZs in the Eastern Cape Province were identified during a SEA of the entire South African

coastline using systematic-based spatial analyses that considered defined criteria work shopped a-priori

with industry stakeholders (Clark et al. 2011). The analysis yielded several potential sites in the Eastern

Cape (three within Algoa Bay) for caged finfish aquaculture. Monitoring commenced at two of the

preferred (based on ranking criteria) sites in 2012, however, during the Scoping Phase objections were

raised with regards to the locations of these two sites due to shipping and safety concerns. Focus then

shifted to the remaining site identified during the SEA (Algoa 1) and an alternative site (Algoa 5) was

identified by relaxing some of the site selection criteria (Clark et al. 2011 & Clark 2012). An earlier

marine specialist report (Hutchings et al 2013) described the affected marine environment and affected

user groups. In this marine specialist report, a description of the finfish cage farming projects that may

be developed within these two marine ADZs in Algoa Bay (should they be approved) is provided along

with an assessment of the potential marine environmental impacts.

Fin-fish cage farming undertaken on the Algoa ADZs will likely take place in circular floating net cages,

20-30m diameter and 15-20m deep. The nylon net mesh will be treated with an antifoulant and

suspended between two PVC rings or rubber flexible hoses that are in turn supported by plastic or

galvanised steel stanchions. Nets will need to be rotated to prevent excessive biofouling. Fish cages will

be moored to the sea bed using steel anchors and chains or mooring blocks. At least 5m will be required

between the net bottom and the sea floor to allow for adequate dispersion of wastes (uneaten food and

faeces). Secondary anti predator net will be installed below and above the water line. Fish farm

operators will need to source fry from shore based hatcheries. This impact assessment covers the use of

indigenous finfish species, such as yellowtail, silver and dusky kob, white stumpnose, white steenbras,

yellowfin tuna etc. that will most likely be farmed in Algoa Bay ADZs. Should a future development wish

to farm an alien finfish species, a risk assessment as specified in NEM:BA will need to be undertaken.

Depending on the species and growth rates obtained, fry will be stocked at around 10-15 grams and

harvested 12-24 months later using scoop nets. Fish will be bled on the workboat and placed in ice, no

blood or offal should enter the water.

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A commercially viable fish farm would need to produce in the region of 3 000 tons of fish per annum.

This would require approximately 35 fish cages each holding ~85 tons of stock. The sea floor footprint

(distance between the outermost moorings) of 20 -50 ha would be 5-10 times greater than the sea

surface footprint. To allow for fallowing and easy workboat access to cages an estimated 70 ha is

required per commercial operator. Theoretically this means that up to nine commercial scale farms

could be accommodated on Algoa 1 and up to 25 farms on Algoa 5. There is high uncertainty

surrounding the environmental and economic impacts associated with this scale of development that

would result in an annual production that would exceed the current SA Linefish catch by 2-5 times. We

therefore adopt a precautionary approach and recommend a much lower initial scale development with

no more than three fish cage farms authorized to scale production up from pilot phase (maximum 1000

tons/ ADZ) to commercial viability (9000 tons per ADZ) over a four year period, providing that

environmental quality objectives are maintained.

Impacts related to the installation of fish cages on the proposed ADZs are limited to the disturbance and

or mortality of benthic marine communities due to the placement of moorings on the sea floor. This

impact is local and long term, but is regarded as reversible and low intensity and is assessed as low

overall significance.

Operational phase environmental impacts of finfish cage culture have been well reported in

international literature and are described in the text, these include:

Incubation and transmission of fish disease and parasites from captive to wild populations.

Pollution of coastal waters due to the discharge of organic wastes.

Escape of genetically distinct fish that compete and interbreed with wild stocks that are often

already depleted.

Chemical pollution of marine food chains (& potential risk to human health) due to the use of

therapeutic chemicals in the treatment of cultured stock and antifouling treatment of

infrastructure.

Physical hazard to cetaceans and other marine species that may become entangled in ropes and

nets.

Piscivorous marine animals (including mammals, sharks, bony fish and birds) attempt to remove

fish from the cages and may become tangled in nets, damage nets leading to escapes and stress

or harm the cultured stock. Piscivorous marine animals may also be attracted to the cages that

act as Fish Attractant Devices (FADs) and in so doing natural foraging behaviors and food webs

may be altered. Farmers tend to kill problem predators or use acoustic deterrents.

User conflict due to exclusion from mariculture zones for security reasons.

Some of the potential operational impacts such as pollution, habitat alteration and user conflict have

been partly mitigated by correct site selection as employed in the SEA and are being verified with

further in situ monitoring. Other potential impacts may be mitigated by astute animal husbandry and

adaptive management strategies. The significance of these various impacts and possible mitigation

measures with respect to the proposed Algoa Bay ADZs are summarized in the Table below.

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Summary Table of assessed potential impacts and mitigation measures for the development of finfish

cage culture on the Algoa ADZs.

Potential Impact

Essential/Recommended Mitigation Significance Confidence

(applicable to ADZ)

Without Mitigation

With mitigation

Disease and parasite transmission to wild fish stocks (Algoa 1 &5)

Essential mitigation measures:

Maintain strict bio-security measures

within hatchery, holding tanks and sea

cages.

Ensure all fry undergoes a health

examination prior to stocking in sea

cages.

Regularly inspect stock for disease

and/parasites as part of a formalised

stock health monitoring programme and

take necessary action to eliminate

pathogens through the use of therapeutic

chemicals or improved farm

management. This will require increased

research effort into the identification,

pathology and treatment of diseases and

parasites infecting farmed species, both

within culture and wild stocks.

Maintain comprehensive records of all

pathogens and parasites detected as well

as logs detailing the efficacy of

treatments applied. These records should

be made publically available to facilitate

rapid responses by other operators to

future outbreaks.

Locate cages stocked with different

cohorts of the same species as far apart

as possible, if possible stock different

species in cages successively.

Treat adjacent cages simultaneously even

if infections have not yet been detected

in these cages.

Keep nets clean and allow sufficient

fallowing time (all cages on ADZ un-

stocked, nets removed and cleaned) on

sites to ensure low environmental levels

of intermediates hosts and or pathogens

-ve Very High -ve High

High Medium

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Pollution of the water column and the benthic environment arising from organic waste discharge (Algoa 1 & 5)


Use species and system specific feeds in order to maximize food conversion ratios (and minimize waste).

Monitor fish feeding behaviour and particulate matter deposition, adapt the feeding strategy to maximise feeding efficiency and minimise particulate matter fallout.

Rotation of cages within a site (fallowing) to allow recovery of benthos (not recommended over long lived habitats (e.g. reefs).

Sensible site selection, namely sufficient depth, current speeds and suitable sediment type (partly achieved in SEA, but reducing the size of Algoa 5 to exclude identified reef and a 500m buffer is recommended).

Prior to any development on either site, conduct a hydrodynamic modelling exercise of waste dispersal using detailed current profiling data (12 months of data should be available from January 2014). Model different levels of ADZ development and predicted waste discharge and ensure that the waste plume does not impact on sensitive habitats such as the Algoa Bay shoreline and Island groups.

Undertake ongoing, detailed water quality and benthic monitoring, including baseline surveys at control and impact sites (as described in the EMPr), and decrease the ADZ carrying capacity should the environmental quality indicator be exceeded outside of the accepted sacrificial footprint.

-ve High -ve Medium Medium

Genetic contamination of wild stocks with escapees from finfish cage culture (Algoa 1)


Maintain genetic compatibility (similar levels of variation) between wild and cultured stock by implementing the “Genetic Best Practice Management Guidelines for Marine Finfish Hatcheries” developed by DAFF.

Reduce the number of escapees by maintain cage integrity through

-ve High -ve Low Low

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regular maintenance and replacement and training of staff.

Develop and implement recovery procedures should escapes occur.

Optional mitigation measures:

Develop the technology to create sterile fry for stocking of cages

Genetic contamination of wild stocks with escapees from finfish cage culture (Algoa 5)

As above

Significance of impact with mitigation remains medium as probability of escapes from fish cages deemed greater than Algoa 1 due to more exposed nature of Algoa 5

-ve High -ve Medium Low

Chemical pollution resulting from the use of chemical therapeutants and antifoulants (Algoa 1)


Use only approved veterinary chemicals and antifoulants

Do not apply antifoulants on site (at sea)

Where effective use environmentally friendly alternatives

Use the most efficient drug delivery mechanisms that minimise the concentrations of biologically active ingredients entering the environment

Use the lowest effective dose of therapeutants

-ve Medium -ve Low

Medium Low

Chemical pollution resulting from the use of chemical therapeutants and antifoulants (Algoa 5)

As above

Significance of impact assessed as greater on Algoa 5 due to the sensitivity of the receiving environment and proximity to breeding colonies of seals and sea birds.

-ve High -ve Medium

Medium Low

Accidental entanglement of cetaceans in finfish cage culture infrastructure (Algoa 1 & 5)


Do not locate ADZs in important cetacean habitats (fortuitously this is the case).

Ensure all mooring lines and nets are highly visual (use thick lines and bright antifoulant coatings).

Keep all lines and nets tight through regular inspections and maintenance.

Ensure that mesh size on primary and secondary nets does not exceed 16 cm stretched mesh, use square

-ve Medium -ve Low Medium

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mesh.

Establish a rapid response unit to deal with cetacean entanglements (collaboration with the South African Whale Disentanglement Network)

Alterations in cetacean habitat use or migration patterns (Algoa 1 & 5)

Recommended mitigation measures:

Keep a log of all cetaceans recorded in the vicinity of fish farms including behavioural observations

Establish a cetacean monitoring programme in order to detect potential changes in cetacean habitat use in the broader Algoa Bay

-ve Low -ve Low Medium

Piscivorous marine animals interacting with finfish cage culture operations (Algoa 1)


Install and maintain suitable predator nets (sufficient strength, visibility and mesh size, above and below water line).

Install visual deterrents (e.g. tori line type deterrents for birds).

Store feed so piscivores cannot access it, and implement efficient feeding strategy.

Remove any injured or dead fish from cages promptly.

During harvesting of stock, ensure that minimal blood or offal enters the water.

Implement mitigation measures as

for entanglement impacts (see above).

Develop a protocol for dealing with problem piscivores in conjunction with experts and officials (DAFF, DEA etc)

Maintain a record of all interactions with piscivores as per recommended EMPr

-ve Low -ve Very Low

Medium Low

Piscivorous marine animals interacting with finfish cage culture operations (Algoa 5)

As above

Assessed as greater risk than Algoa 1 due to the proximity of seal colony on St Croix island group

-ve High -ve Medium

Medium

Safety of recreational water sport participants (Algoa 1)


Implement mitigation measures as above to try reduce interaction with large marine piscivores.

Monitor large shark movement

-ve Low -ve Low Low

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patterns before and after ADZ development as per recommended EMPr monitoring components

Safety of recreational water sport participants (Algoa 5)

As above -ve Very low -ve Very low Low

Impacts on recreational SCUBA divers (Algoa 1)


Implement mitigation measures as above to try reduce organic and chemical pollution.

Implement recommended benthic monitoring and adaptive management EMPr monitoring components.

-ve High -ve Medium Low

Impacts on recreational SCUBA divers (Algoa 5)

As above -ve Very low -ve Very low Low

Impacts on yacht sailing and recreational boat anglers (Algoa 1 & 5)


Install navigational markers and lights as required by SAMSA regulations.

Include position of ADZs on navigational charts.

Ongoing consultation with user groups to keep them informed of the ADZ developments.

-ve Low -ve Very low High

Impacts on commercial squid and longline shark fisheries


Reduce the size of the ADZs

-ve High -ve Very low High

Impact on conservation objective – declaration , functioning and management of the proposed Addo Elephant MPA


NO- GO option

-ve High NA High

Given the predicted medium and high significance impacts on marine vertebrates, particularly on sea

birds, seals, sharks and cetaceans associated with the St Croix and Bird islands, as well as the position

within a proposed MPA (thus contrary to conservation objectives) the development of Algoa 5 as an ADZ

is not recommended. The economic viability of this site, due to its exposed position and distance from

port is also questionable. Algoa 1 is far more favourable from a mariculture industry perspective, whilst

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genetic impacts and impacts on large marine fauna are rated substantially lower than for Algoa 5.

Predicted impacts due to organic and chemical waste generation and disease introduction to wild stocks

are assessed as being of a similar significance at both sites, and user conflict, particularly with the

established fisheries (specifically squid) and recreational water users, are higher for Algoa 1.

Issues identified during the 2011 SEA and this EIA process, namely: the linear, very exposed coastline (all

countries that are major fish cage culture producers have glaciated coastlines or extensive sheltered sea

space); high levels of existing development and use of the little available sheltered sea space;

vulnerability of important wild fish stocks to potential disease and genetic impacts; and abundance of

large and/or endangered marine vertebrate fauna that are common in inshore coastal waters, indicate

that “inshore” sea cage culture may not be viable in South Africa. It appears that the future of finfish

mariculture development should focus on shore-based, recirculating systems that carry lower

environmental and economic risks. The technology for this already exists, and successful, commercial

scale, shore-based finfish farms are already in operation in the East London IDZ. Alternatively the

research and development of “offshore” cage technology (including robust submersible cage designs

and automatic feeders etc.) that can be deployed in areas with substantially lower potential

environmental impacts and user conflict will be a more viable future for this industry in South Africa.

Should Algoa 1 be declared as an ADZ, on-going, comprehensive environmental monitoring and adaptive

management concurrent with a phased development of the ADZ must be implemented. Recommended

marine monitoring components for an Environmental Management programme are provided.

.

Contents 1 Introduction ........................................................................................................................................ 11

2 Proposed project description .............................................................................................................. 13

2.1 Fish cage infrastructure .............................................................................................................. 13

2.2 Potential culture species ............................................................................................................. 16

2.3 Sea cage fish farm operations ..................................................................................................... 18

3 Marine environmental impact assessment ........................................................................................ 20

3.1 Potential construction phase impacts ........................................................................................ 20

3.2 Operational phase environmental impacts ................................................................................ 21

3.2.1 Disease and parasites .......................................................................................................... 22

3.2.2 Organic pollution from sea cages........................................................................................ 24

3.2.3 Genetic impacts on wild stocks ........................................................................................... 26

3.2.4 Chemical pollution arising from finfish cages ..................................................................... 28

3.2.5 Entanglement of cetaceans and other species ................................................................... 30

3.2.6 Interactions with piscivorous marine animals .................................................................... 33

3.2.7 User conflict ........................................................................................................................ 34

4 Recommended Algoa Bay ADZ development and management ........................................................ 39

5 Recommended marine monitoring components of an EMPr for the Algoa ADZs .............................. 41

6 References .......................................................................................................................................... 51

7 Appendix 1. Impact Rating Methodology ........................................................................................... 57

.

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1 Introduction

The stated purpose of establishing Aquaculture Development Zones (ADZs), as presented by the

Directorate Sustainable Aquaculture Management: Aquaculture Animal Health and Environmental

Interactions, in the Department of Agriculture, Forestry and Fisheries (DAFF), is to encourage investor

and consumer confidence in the marine aquaculture industry in South Africa, and also to create

incentives for industry development, provide marine aquaculture services, manage risk associated with

aquaculture, and provide skills development and employment for coastal communities. The DAFF has

identified the Eastern Cape as a priority region for establishing ADZs in South Africa. A Strategic

Environmental Assessment (SEA) conducted by Anchor Environmental Consultants (Clark et al 2011) has

identified several potential sites in the Eastern Cape.

The two sites in Algoa Bay, referred to as Algoa 2 and Algoa 3 (previously called Port Elizabeth2 (Algoa 2)

and Port Elizabeth3 (Algoa 3) in the SEA report), were initially the focus of the EIA. These potential ADZs

were identified using multiple criteria work shopped with stakeholders from government and industry

with spatial GIS-based analyses and a post-hoc ranking system (Clark et al 2011). In situ baseline

assessments on the biology and oceanography at these two ADZs (Algoa 2 and Algoa 3) commenced in

February 2012. However, during the Scoping Phase, concerns pertaining to safety and shipping were

raised by Transnet regarding the proposed locations of the two ADZs (Clark 2012).

Algoa 1 was determined as the next-best option, in addition to Algoa 5 which, although not conceived in

the original SEA, was an area that required relaxing the least amount of exclusionary criteria; in this case

the criterion of proposed marine protected areas (MPAs) (see Clark 2012). In situ monitoring

instrumentation was therefore retrieved from Algoa 2 and Algoa 3 and redeployed at Algoa 1 and Algoa

5 in February 2013 and is ongoing. A “Description of the Affected Environment and Existing Marine

Users Report” summarizes the results of ongoing baseline monitoring and available biological and

oceanographic information for these sites (Hutchings et al. 2013).

This report describes the probable finfish farm developments that may take place on the proposed

Algoa 1 and Algoa 5 ADZs (should they be declared), and assesses the potential impacts on the marine

environment. This EIA is for the declaration of a marine finfish ADZ rather than a specific finfish farm

development with specified technical details. The project description is based on available literature

and web based sources, as well as the consultants’ expert opinions of what infrastructure and species

may be suitable for the proposed sites. The assessment of impacts is therefore applicable to the project

description presented in this report, and is by necessity, generic in nature. Impacts are also assessed

under the maximum development scenario, i.e. the ADZ is fully developed with fish cages at the

maximum viable density as determined by the required sea space per commercially viable farm.

Consultation with industry has revealed that a 3 000 ton-per-year production is considered the

minimum economically viable scale of operation for a single operator. A sea space of approximately 60-

70 ha is required to develop a farm with this level of production. During consultation with industry, a

minimum ADZ size of 200 ha was suggested so as to accommodate at least three commercially viable

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farms. As the viability of marine finfish cage farming under South African conditions is still under

investigation, the actual infrastructure used and species cultured may differ from those assessed here.

Should this be the case with a future development, a project specific assessment of impacts should be

undertaken.

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2 Proposed project description

2.1 Fish cage infrastructure

The 2011 SEA described design criteria, available fish cage types and the suitable oceanographic

conditions for their use (Clark et al 2011). Given the research and development stage of sea-based

finfish cage culture in South Africa, and the prevailing environmental conditions, it is probable that some

type of floating, plastic ring or flexible hose cage could be used on the proposed Algoa ADZs. Monitoring

of the wave climate within Algoa Bay revealed that significant wave heights were less than 2 m for ~90%

of the time, suggesting that most types of plastic circle cages will be suitable in the water depth at the

proposed ADZs (20-50m). However, it is the forces during extreme storm events that the cage

infrastructure needs to withstand. Depending on the exposure to risk that future fish-cage farm

operators are comfortable with, “offshore” plastic circle or flex hose cages may be more suitable for use

within Algoa Bay, given that significant wave heights of up to 5 m were recorded during storm events

during 2012 (Clark et al 2011, Hutchings et al. 2013). Similar fish cages have been used in a pilot study

within Algoa Bay and proved suitable for the local conditions, albeit in a more sheltered location than

either of the two proposed ADZs. Cages of this design were also proposed for a commercial scale finfish

cage development in Mossel Bay and the description of cage type, mooring and maintenance is

extracted from reports compiled for these projects (Schoonbee and Bok 2006, CCA Environmental

2008).

It must be stressed that wave climate measurements at Algoa 2 to date have covered an 11-month

period, at one site in 25 m water depth offshore of Coega Port. The Algoa 5 site may experience

considerably greater significant wave heights from the south west during winter storms due to its

position further east and out of the lee of Cape Recife. The wave climate is currently being monitored

at both Algoa 1 and Algoa 5, but it must always be acknowledged that storm generated waves with a

return period greater than the monitoring period may not be recorded (i.e. the probability of recording

a 1 in 5 or 10 or 50-year storm event is low during a 12-month monitoring study). Future finfish farm

operators may assess the risk, costs and returns, and decide to utilize different, more robust (possibly

submersible) cage designs. Although not commonly used internationally, a variety of “offshore” cage

designs are available, but many are considered experimental. Research and development as to the

suitability of these cage types in South African conditions will need to take place, and although we do

not rule out their possible future use in the potential Algoa ADZs, we have based the project description

on the floating circular cages that we believe are most likely to be used.

The most likely fish cages for commercial finfish outgrowing in the proposed Algoa ADZs would be 70-

100 m in circumference (diameter = 20-30 m) and approximately 15 m deep. To prevent build up of

wastes (uneaten food and faeces) below the cages, which would harm the stock, at least 5 m is required

below the cage bottom to allow for adequate dispersion. For this reason, both the potential ADZ sites

are deeper than 20 m. The sluggish currents that predominate in Algoa Bay (see Hutchings et al. 2013),

however, indicate a need for greater depth below the cage floors or more frequent fallowing, especially

as farms approach full production capacity. Cages would probably be moored either in a grid pattern or

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individually using rope lines, steel chains and anchors or concrete mooring blocks. Depending on the

mooring systems used, the sea floor footprint (i.e. the total area between the outermost moorings) will

be substantially larger (~5-10 times greater) than the sea surface footprint (Figure 1).

Figure 1. Example of a finfish sea cage mooring system, showing larger size of sea-floor footprint compared to the sea surface footprint.

A commercially viable, finfish cage farm, producing in the region of 3 000 tons per year, would require

about 35 cages of this size, holding approximately 85 tons of fish each (these figures are based on the

I&J proposal to farm yellowtail and kabeljou and may vary depending on the species farmed). The sea

floor footprint of a farm this size would be about 20-50 ha depending on the mooring system, but to

allow for boat access between cages and fallowing of sites, an area of around 70 ha per operator would

be required. This suggests that should the ADZs be fully developed, Algoa 1 could theoretically

accommodate nine commercial scale finfish farms with a total production of ~30 000 tons per annum,

and Algoa 5 could accommodate around 25 farms producing 75 000 tons/year. These quantities exceed

the average annual total South African line fish catch by 2-5 times (Griffiths 2000), and full development

of these sites would therefore be reliant on producers accessing new markets for farmed finfish. It is

uncertain that this scale of development will be sustainable both from an environmental impact

perspective and from industry functionality/economic perspective. We therefore adopt a precautionary

approach and recommend a much lower initial scale development with no more than three fish cage

farms authorized to scale production up from pilot phase (maximum 1000 tons/ ADZ) to commercial

viability (9000 tons per ADZ) over a four year period, providing that environmental quality objectives are

maintained.

Anchor and chainMooring rope

Marker buoysFloating circular

fish cage

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Net types would probably be polyester or nylon nets with variable mesh sizes (dependent on the size of

fish stocked and stage of outgrowing). For species currently under consideration (see Section 2.2) mesh

size would range between 20-40 mm stretched mesh (this is likely to vary for different species and type

of production techniques introduced). The nets would be supported between two rings, constructed

from High Density Poly-Ethylene (HDPE) pipes or possibly flexible rubber hose that may prove more

suitable for the wave and sea climate on the sites. The rings are held together by plastic or galvanized

steel stanchions that hold the cage structure together (Figure 2). Nets would need to be coated with an

antifouling compound, probably a copper based product, to prevent excessive biofouling of the mesh.

To reduce incidents of large marine piscivores predating on cultured stock, a large mesh (anti-predator

net mesh size should not exceed 16 cm to minimize entanglements) would need to be installed on all

underwater sides of the primary cage mesh. A similar, but smaller mesh, predator net over the top of

the cages will be required to prevent stock escape and sea birds preying on the stock (Figure 3). Copper

alloy mesh cages are an alternative approach to reduce biofouling and predation, and future operators

may use this material, although the initial capital outlay is much greater (Prof. Tom Hecht, Advance

Africa Management Services, personal communication). Nonetheless, antifouling coatings have limited

life spans and regular net changes would be required as necessary. In order to minimize risks to other

shipping, all cages will need to be marked with cardinal marker buoys with radar reflection and

navigational lights indicating their position. The fish cage structure (rings, stanchions and cover nets)

would extend approximately 1-2 m above, and 15 m below the sea surface.

Figure 2. Floating circular fish cage showing the rings and stanchions (source: http://www.pensito.eu)

HDPE or

Flex-hose

rings

Stanchions

16

Figure 3. Circular fish cages of a similar design likely to be deployed in the Algoa ADZs

2.2 Potential culture species

The sustainable aquaculture policy does not rule out the use of alien species (Government gazette No

30263, pg 13), provided that a risk assessment as described in the National Environmental Management

Biodiversity Act (NEM:BA act Government Gazette no. 26436 June 2004) is undertaken. Indeed,

experimental sea cage farming with Atlantic salmon Salmo salar has taken place at Gansbaai and a

scoping study for salmon farming at Saldanha Bay is currently underway. The warm temperate waters

of Algoa Bay however, are not suitable for many cooler water species (e.g. salmon, flounder, and plaice)

that were initially the mainstay of finfish sea cage culture internationally nor warm enough for more

recently researched tropical species (such as cobia). Risks of disease and parasite introduction, or the

establishment of an invasive alien fish species, are generally considered lower if indigenous species are

cultured, although disease transmission to local wild stocks is more likely. It is probable that future fish

farm operators would attempt to farm indigenous or alien fish species based entirely on the estimated

economic viability for each species. This application is however, for the cage culture of indigenous

finfish species and should future operators wish to farm with alien species they would need to complete

a detailed risk assessment as specified in the National Environmental Management: Biodiversity Act of

2004 (NEM:BA).

Around 250 species are landed by South Africa’s line fisheries, although around a dozen account for

more than 90% of the catch (Mann 2000). Given that a domestic market already exists for popular

linefish species, these species are the most likely initial candidates for cage culture. Research and

development into the suitability of three of these species for sea cage culture has already occurred

within Algoa Bay, namely for yellowtail Seriola lalandi, dusky kob Argyrosomus japonicus and silver kob

Argyrosomus inodorus (Nel and Winter 2008, 2009). Several species of the genus Seriola are used in

Small mesh

cover to

prevent

stock

escape and

bird

predation

17

aquaculture internationally, with a global aquaculture production of more than 150 000 tons, mostly

(80%) of Japanese yellowtail S. quinqueradiata that is farmed in Japan and Korea. Seriola lalandi is

commercially farmed in sea cages in Australia (since 2001) with a production of ~ 3300 tons in 2007/8,

and has been trialled in Chile and New Zealand (Poortenaar et al. 2003, Frenandes & Tanner 2008,

Moran et al. 2009). The World Wide Fund for Nature (WWF) has initiated a Seriola and Cobia

Aquaculture Dialogue (SCAD), with the stated purpose of “creating standards that will minimize the key

impacts of Seriola/Cobia aquaculture and move producers towards better performance”. Argyrosomus

japonicus has been farmed in Australia where it is locally known as Mulloway and both of this Sciaenid

and A. inodorus are congenerics of meagre Argyrosomus regius that is extensively farmed in sea cages in

the Mediterranean, with an estimated production of 15 000 tons in 2010 (FAO 2012). Several other

indigenous fish species are also under consideration, namely, tuna (presumably yellowfin Thunnus

albacares), sole (species not given), several sparids including, white steenbras Lithognathus

lithognathus, white stumpnose Rhabdosargus globiceps and red roman Chrysoblephus laticeps; another

Sciaenid geelbek Atractoscion aequidens, and the Haemulid spotted grunter Pomadasys commersonnii

(DEA 2013, Government Gazette No. 36145).

Algoa Bay falls within the core distributions of all of the above mentioned indigenous species, indicating

that the environmental conditions are, at times, suitable for these species (Hutchings et al. 2013). The

presence of local wild populations does not, however, confirm suitability of a species for sea cage

culture in the area. Sea cages restrict the natural movement of the stocked species that may have

evolved behavioral responses to variable oceanographic conditions. For example, both Sciaenids

stocked in the Algoa Bay sea cage trials did not do well, with low growth rates and susceptibility to

parasites. This was thought to be partly caused by sudden drops in water temperature experienced at

the site (G Le Roux, Stellenbosch University, personal communication). Telemetry studies on dusky kob

within Algoa Bay have revealed population specific movement responses to changes in water

temperature with individual fish displaying site fidelity to estuaries that are used as refugia during

periods of low sea water temperature (P Cowley, SAIAB, personal communication).

Research and development into the suitability of different species for cage culture under South African

conditions is ongoing, and additional candidate species to those mentioned above may also be trialled.

At this point in time, it seems likely that yellowtail will be the first species for which commercial scale

sea cage culture is attempted within Algoa Bay (should either of the ADZs be declared). A positive

market response will be required if cage farming yellowtail (or any other species) is to be economically

viable. Future fish farmers in South Africa will either have to develop and grow local markets for fish

(using the continuity of supply and high quality of aquaculture product as marketing points); compete

with countries with established finfish cage industries on international markets; or produce fish at a

lower cost than South Africa’s wild capture fisheries can catch them. Diversification of species for use in

local sea cage culture will depend on research and development around stock husbandry (including

viable hatchery techniques), suitability of species to caged conditions (along with suitability of cages for

local sea conditions), and the development of receptive markets. High value species for which sea cage

culture techniques are known, an international market demand already exists and wild capture volumes

are declining (e.g. yellowfin tuna), could well prove the most economically viable.

18

2.3 Sea cage fish farm operations

Sea cage fish farmers will need a reliable source of disease free fry with which to stock sea cages. These

may be supplied from established hatcheries or companies may decide to initiate their own hatcheries.

In either case, strict biosecurity measures will need to be enforced, whilst the breeding protocol will

have to adhere to the DAFF genetic best practice management guidelines for marine finfish hatcheries.

After acclimatization in holding tanks, fry will be stocked in sea cages at a size at which survival and

growth will be optimised. This will be species specific and determined by on site trials. As an example

during the trials undertaken in Port Elizabeth to date, yellowtail and kob were stocked in cages at 5-11 g

in size (Nel and Winter 2009).

All farm operations (e.g. equipment maintenance, feeding, general husbandry, harvesting) will take

place using suitable size workboats equipped with cranes that would need to be based in either Port

Elizabeth or Coega ports. Optimum stocking densities and feeding rates, during each season and for

different species of fish of different size classes, can only be determined after several seasons of rearing

have taken place at each site (Schoonbee and Bok 2006). Achieving optimum stocking rates are partly

dependent on the water depth and current speeds at the farm sites. Current speeds within Algoa Bay

tend to be sluggish, but may be slightly improved at the more exposed Algoa 5 and Algoa 1sites, than

those measured at 25 m water depth off Coega (Hutchings et al. 2013). As the farmed stock grows, they

should be transferred to cages with larger mesh size in order to maximize water exchange and hence

water quality. For the same reasons, nets will need to be treated with antifoulant coatings and changed

as required to maintain high water quality within the cages. Failure to do so will result in poor fish

health and growth rates.

Moving of the cages within the farm footprint (when referring to benthic impacts this is termed

fallowing of sites; when referring to a mitigation for disease and parasite build up the term fallowing

means leaving cages in an entire mariculture area un-stocked) may help to prevent the build up of

organic wastes under the cages which has negative environmental impacts and may impact on the

health and survival of stock. It must be noted that studies of salmon farm impacts on benthic

environments have not recommended fallowing where long-lived biogenic habitats occur because this

will likely increase the area of habitat degradation (Hall-Spencer and Bamber 2007). Reef area detected

within Algoa 5 during the bathymetry and grab sampling surveys should therefore be excised from the

potential ADZ.

Fish will probably be fed on commercially available, compound feeds e.g. Aquanutro, but new feeds may

need to be developed depending on the species farmed. A food conversion ratio of 1.3-2.8 kg dry

weight food per 1 kg wet weight fish produced has been reported in the international literature for

yellowtail (Fernandes and Tanner 2008, Moran et al. 2009). This appears realistic for conditions within

Algoa Bay, as the Port Elizabeth trials resulted in a maximum biomass of ~ 30 tons of fish with a food

input of ~ 70 tons over a 21 month period (Nel and Winter 2009). Depending on the species farmed and

growth rates attained, harvesting of fish will probably take place using a scoop net, 12-24 months after

stocking. Harvested fish will probably be bled and placed in ice slurry on board the work boat and then

transported to a licensed, shore-based fish processing facility. Harvesting should aim to prevent any

19

blood or offal entering the water (which would decrease water quality and attract piscivores e.g. sharks)

and this should be disposed of or processed in an approved land based facility.

20

3 Marine environmental impact assessment

Environmental impacts of finfish cage farming have been well documented and reported in international

literature (e.g. see: Stickney & McVey 2002, Staniford 2002). A brief description of the potential

environmental impacts of finfish cage culture follows. In the early period of finfish farming

internationally, particularly salmon farming in the pioneering countries, a lack of good environmental

management and poor farming practices led to significant, negative environmental impacts occurring.

This resulted in negative attitudes and opinions amongst the public and conservation organizations

towards the industry. This negative sentiment towards sea cage fish farming persists to this day, despite

an increasing focus on sustainability by both governments and industry. In a proactive move, the South

African Marine Finfish Farmers Association of South Africa (MFFASA) has compiled their own Marine

Fish farming Environmental Impact Information document (MFFASA 2010) that includes a code of

conduct and identifies most of the known environmental impacts of finfish farming. Unfortunately

many of the environmental impacts of cage farming are expensive and difficult to mitigate and the

opposition to industrial scale fish cage culture remains strong. Nonetheless, some of the potential

impacts of finfish sea cage farming may be partially mitigated by selection of appropriate sites only

(Clark et al 2011). Mitigation for other impacts can only be addressed when operational specific data

are available, and should be implemented via an approved Environmental Management Programme

(EMPr). Recommended marine monitoring components of an EMPr for the Algoa ADZs are given in

Section 5. The impact assessment methodology used in this report is given in Appendix 1.

The impacts of mariculture depend on the species, culture method, stocking densities, feed type,

hydrography of the site and husbandry practices (Wu 1995).

3.1 Potential construction phase impacts

Construction phase impacts on the marine environment are limited to those caused by the placement of

cages and mooring infrastructure on the sites. The mooring anchors, chains and ropes will have a

negative impact (mortalities, loss of habitat) on benthic communities directly within the footprint of

anchors or mooring blocks and the movements of mooring chains and ropes may cause further

mortalities and or disturbance to benthic communities. Seabed acoustic surveys reveal that both the

proposed ADZ sites are largely sandy substratum (Hutchings et al. 2013). The impact is localized and of

low intensity, and is assessed as having low overall significance (Table 1). Potential impacts of cage

infrastructure on marine vertebrates due to entanglement start as soon as infrastructure is installed, but

is assessed under operational phase impacts below.

Table 1. Assessment of the possible impacts on the benthic environment arising during the construction phase from the installation of cages and associated moorings on proposed Algoa 1 and Algoa 5 ADZs

21

Extent Intensity Duration Consequence Probability Significance Status Confidence

Without

mitigation Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Definite

Low

– ve

High


Do not moor cages over long lived biogenic habitats (reef area identified within Algoa 5 should be excluded from

potential ADZ)


Ensure mooring system is well designed to prevent/limit movement of anchors and chains over the sea floor.

Do not move mooring anchors or blocks when undertaking cage net maintenance or fallowing sites, as replacement

of moorings when site is used again will increase impact footprint.

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Definite

Low

– ve

High

3.2 Operational phase environmental impacts

Operational phase environmental impacts of finfish cage culture include:

Incubation and transmission of fish disease and parasites from captive to wild populations.

Pollution of coastal waters due to the discharge of organic wastes.

Escape of genetically distinct fish that compete and interbreed with wild stocks that are often

already depleted.

Chemical pollution of marine food chains (& potential risk to human health) due to the use of

therapeutic chemicals in the treatment of cultured stock and antifouling treatment of

infrastructure.

Physical hazard to cetaceans and other marine species that may become entangled in ropes and

nets.

Piscivorous marine animals (including mammals, sharks, bony fish and birds) attempt to remove

fish from the cages and may become tangled in nets, damage nets leading to escapes and stress

or harm the cultured stock. Piscivorous marine animals may also be attracted to the cages that

act as Fish Attractant Devices (FADs) and in so doing natural foraging behaviors and food webs

may be altered. Farmers tend to kill problem predators or use acoustic deterrents.

User conflict due to exclusion from mariculture zones for security reasons or negative impacts

on tourism and coastal real estate value due to negative aesthetic impacts of fish farms.

The significance of these various impacts and possible mitigation measures with respect to the proposed

Algoa Bay ADZs are assessed in more detail below.

22

3.2.1 Disease and parasites

In fish cage aquaculture, high stocking densities (typically 15-20 fish per m3) serve as a breeding ground

for disease and parasite infections (including blood, intestinal and ecto-parasites). Infectious diseases

and parasites are regarded as the single biggest threat to aquaculture, with the estimated losses from

sea lice (genus Caligus) infections of salmon stock alone amounting to hundreds of millions of dollars

annually (Staniford 2002, Heuch et al. 2005). The cultured stock is often prevented from exercising

natural parasite shedding behaviours and the high number of concentrated hosts facilitates parasite and

disease reproduction and transmission. This is not only a concern for the productivity of the cultured

stock, but also threatens wild stocks due to enhanced transmission of parasites and diseases (Heuch et

al. 2005, Krosek et al. 2007, Ford and Myers 2008). Transmission to wild stocks may take place by direct

contact between wild fish and farmed stock as wild fish are often attracted to the cages, or simply as a

result of the much higher concentration of pelagic parasite life history stages arising from fish farms.

Wild salmon in particular have suffered increased parasite infection rates due to contact with cage

cultured stock (Carr and Whoriskey 2004, Heuch et al. 2005). Documented effects of high parasite loads

on wild salmonids include increased mortality rates, reduced fecundity and delayed maturity, all of

which reduce the fitness of individuals and the productivity of the wild stock as a whole (Bjorn et al.

2002, Carr and Whoriskey 2004, Heuch et al. 2005, Ford and Myers 2008). Intensive sea bass and sea

bream culture in the Mediterranean has also resulted in severe disease problems in fish farms; problem

diseases include Pasteurellosis and Nodavirosis, and parasitic infections include Ichtyobodo sp.,

Ceratomyxa sp., Amyloodinium ocellatum, Trichodina sp., Myxidium leei, and Diplectanum aequans

(Agius and Tanti 1997 cited in Staniford 2002). In Australia, experiments have revealed that

Monogenean parasites, infected yellowtail up to 18 km downstream of the cages (Chambers and Ernst

2005). Gill and skin flukes were identified as one of the major factors holding back Australian yellowtail

production (Moses et al. 2009). Indigenous species currently under consideration for sea cage

mariculture in South Africa include silver and dusky kob (Argyrosomus inodrus and A. japonicus) and

yellowtail Seriola lalandii. The parasites and diseases infecting these (and other finfish) species in South

African waters are not well studied, although both kob species are known to be infected by sea lice of

the same genus (Caligus) that caused serious problems amongst salmonids, as well as other copepod,

trematode, Acanthocephalan (parasitic worm) monogean (specifically the gill fluke Diplectanum oliverii),

dinoflagellates (Amyloodinium ocellatum) and myxozoan species (DEAT undated Grobler et al. 2002,

Christison & Vaughan 2009, Joubert et al. 2009). Sciaenids farmed elsewhere, namely dusky kob in

Australia and meagre A. regius in the Mediterranean have also proved susceptible to monogean gill

parasites that caused disease and mortality (Hayward et al. 2007, Merella et al. 2009).

Dusky kob are migratory and yellowtail are regarded as nomadic, whilst silver kob within the vicinity (10-

100 km) of future sea cages will also likely come into contact with farmed stock (Mann 2000). All three

of these species (and any others with nomadic or migratory movement patterns) will therefore be at an

increased risk of contracting diseases and or parasites from stocked fish and spreading them through

wild populations. Potential negative effects on wild stocks are particularly concerning as all three of

these species are important in the commercial and recreational line fisheries and furthermore, both wild

kob species are assessed as collapsed (Grifitths 2000). Dusky kob has recently been assessed using IUCN

23

criteria and is considered Vulnerable in South Africa (Sink et al. in prep). Although treatment of cultured

stock to control disease and parasite outbreaks is possible (unlike wild stocks), chemical treatment is not

without further environmental impacts, whilst build up of antibiotic and chemical resistance is becoming

increasingly problematic (Staniford 2002).

Potential disease and parasite transmission to wild stocks could have negative impacts throughout the

natural distributional range of the species, the magnitude of the potential impact will be high as it could

alter wider natural (ecosystem impacts) and social functions (fisheries), and the impact will be ongoing.

Mitigation measures are not entirely effective, and the overall significance of the impact is estimated as

high to very high (Table 2).

Table 2. Assessment of the possible impacts arising from of disease and parasite transmission to wild fish stocks with the development of finfish cage culture on the proposed Algoa 1 and Algoa 5 ADZs


Without

mitigation

Regional

(distributional

ranges of

indigenous

species)

2

High

3

Long term

(ongoing,

may be

reversible)

3

Very high

8

Definite

Very High

– ve

High


Maintain strict bio-security measures within hatchery, holding tanks and sea cages.

Ensure all fry undergoes a health examination prior to stocking in sea cages.

Regularly inspect stock for disease and/parasites as part of a formalised stock health monitoring programme and

take necessary action to eliminate pathogens through the use of therapeutic chemicals or improved farm

management. This will require focussed research effort into the identification, pathology and treatment of diseases

and parasites infecting farmed species, both within culture and wild stocks.

Maintain comprehensive records of all pathogens and parasites detected as well as logs detailing the efficacy of

treatments applied. These records should be made publically available to facilitate rapid responses by other

operators to future outbreaks.

Locate cages stocked with different cohorts of the same species as far apart as possible, if possible stock different

species in cages successively.

Treat adjacent cages simultaneously even if infections have not yet been detected.

Keep nets clean and allow sufficient fallowing time* on sites to ensure low environmental levels of intermediates

hosts and or pathogens.

With

mitigation

Regional

2

Medium

2

Long term

3

High

7

Probable

High

– ve

Medium

*Note: “Fallowing” as a parasite and disease mitigation measure refers to leaving all cages within an ADZ area (or

bay) un-stocked for a period of at least two months. “Pseudo-fallowing” in this respect can be achieved by stocking

all cages with a different species therefore lowering the environmental load of species specific pathogens (this

obviously is not mitigation for benthic impacts and does not help with pathogens/parasites that infect a broader

number of species). The economic practicality of implementing effective fallowing (cages un-stocked) in a

pioneering industry with only one available site is not known, but this should be considered until better

information on parasite and disease risk of cage culture with locals species is available.

24

3.2.2 Organic pollution from sea cages

Untreated wastes resulting mainly from uneaten food and faeces of fish in sea cages are discharged

directly into the sea and are not an insignificant source of nutrients (Brooks et al. 2002, Staniford 2002).

Studies have documented increased dissolved nutrients and particular components (POC and PON) both

below, and in plumes downstream, of fish cages (Pitta et al. 2005). These wastes impact both on the

benthic environment and on the water column. Sediments and benthic invertebrate communities under

fish farms usually show chemical, physical and biological changes attributable to nutrient loading.

Elevations in carbon, ammonia and hydrogen sulphide concentrations are frequently observed (Carroll

et al. 2003, Heggoey et al. 2005). Nutrient enrichment and resulting eutrophication of sediments under

fish cages is regarded as a serious issue in some areas (Staniford 2002). Impacts on benthic habitats

below fish cages do, however, tend to be localized. Most studies indicate that the effect is contained

within a few hundred meters (Porrello et al. 2005, Merceron 2002 and Kempf et al 2002), but one

Mediterranean study was able to detect changes up to 1000 m away (Sara et al. 2004). The extent of

contamination of the sediments under fish cages is obviously highly site and project specific. Nearshore

marine environments with low flushing rates and or sediments susceptible to organic loading should be

avoided when selecting sites for finfish cages. Cages should also be situated in water of sufficient depth

to allow flushing and reduce the build up of wastes directly below cages. Fallowing is the standard

mitigation method used to allow recovery of sediments under fish cages, but recovery has been

observed to take up to fifteen months after the closure of a Scottish fish farm (Black et al. 2004).

Fallowing is also not recommended over long-lived biogenic habitats such as reefs, as this simply

increases the impact footprint (Hall-Spencer and Bamber 2007). Feeding by wild fish on the wastes and

uneaten food below cages has also been shown to mitigate the impacts of waste on benthic

environments. Some studies have reported that 40-80% of the uneaten food and waste falling out of

cages was eaten by wild fish (Vita et al. 2004, Felsing et al. 2005). This in turn, however, may increase

the risk of parasite and disease transmission to wild stocks and may also attract piscivores to cages with

the associated problems thereof discussed below.

Nutrient loading, of the water column along with the reduction of dissolved O2 concentrations, as a

result of fish cages has been implicated in conditions that stimulate harmful algal blooms, which pose a

threat to human health and shellfish mariculture operations (Gowen & Ezzi 1992, Berry 1996, 1999,

Davies 2000, Navarro 2000, Ruiz 2001, all cited in Staniford 2002).

A recent modelling study of nutrient discharges from Australian yellowtail (S. lalandi) farms indicates

that this species may have a significantly higher eutrophication impact than other cultured finfish

species (Fernandes & Tanner 2008). This species is amongst the most likely to be utilized in Algoa Bay

ADZs and in combination with the relatively sluggish currents within the bay, the probability of negative

benthic and water quality impacts is high. The amount of settable faecal solids, total nitrogen and total

phosphorus however, appears highly dependent on the type (brand, size, floating/sinking) and quality of

pellet feed used (Moran et al 2009). Modelling of waste (nutrient and chemical) dispersal from a single

proposed commercial scale fish farm at Mossel Bay (an area with similar current speeds to Algoa Bay)

has been conducted (Mead et al. 2009). Settable waste was expected to sink to the sea floor within 200

25

m of the cages (Mead et al. 2009). This study did indicate that elevated levels of dissolved nutrients

would likely occur up to 2 km from the fish cages, with nitrate levels expected to be above background

concentrations 8-12 km from the site under certain oceanographic conditions and assumed a very

efficient Food Conversion Ratio (FCR) of 1.2 in modelling calculations (Mead et al. 2009). The cumulative

impact of organic waste discharge from several commercial scale fish farms is likely to be significantly

negative.

The footprint and potential scale of development of the proposed Algoa 5 ADZ is considerably larger

than that for the proposed Algoa 1 ADZ, whilst reef area was also identified within the Algoa 5 ADZ. The

potential impact of waste disposal on water quality and the benthic environment is nonetheless

assessed as similar for both sites (Table 3). It must however, be highlighted that mitigation will be

increasingly more difficult as both ADZs are developed and cumulative impacts of waste disposal

increase (more so for Algoa 5). The impact of organic waste discharge is assessed as having a high

overall significance (medium with effective mitigation). A hydrodynamic modelling study using detailed,

site-specific current modelling data should be conducted prior to any development. The results of this

study with respect to the potential impacts on sensitive habitats (reefs, rocky shores, bathing beaches)

should be used to guide the scale of developments on the ADZs (i.e. if the waste plume is modelled to

reach sensitive habitats that carrying capacity of the ADZ should be reduced).

Table 3. Assessment of the possible impacts on the water column and benthic environment arising from organic waste discharge with the development of finfish cage culture on the proposed Algoa 1 and Algoa 5 ADZs


Without

mitigation

Local

1

High

3

Long term

(ongoing,

but

reversible)

3

High

7

Definite

High

– ve

Medium

(monitoring

required to

determine the

intensity of

impact)


Use species and system-specific feeds in order to maximize food conversion ratios (and minimize waste)

Monitor fish feeding behaviour and particulate matter deposition, adapt the feeding strategy to maximise feeding efficiency and minimise particulate matter fallout.

Rotation of cages within a site (fallowing) to allow recovery of benthos (not recommended over long lived habitats (e.g. reefs).

Sensible site selection, namely sufficient depth, current speeds and suitable sediment type (partly achieved in SEA, but reducing the size of Algoa 5 to exclude identified reef and a 500 m buffer is recommended).

Prior to any development on either site, conduct a hydrodynamic modelling exercise of waste dispersal using detailed current profiling data (12 months of data should be available from January 2014). Model different levels of ADZ development and predicted waste discharge and ensure that the waste plume does not impact on sensitive habitats such as the Algoa Bay shoreline, important reefs and Island groups.

Undertake ongoing, detailed water quality and benthic monitoring, including baseline surveys at control and impact sites (as described in Section 5), and decrease the ADZ carrying capacity should the environmental quality indicator be exceeded outside of the accepted sacrificial footprint.

26

With

mitigation

Local

1

Medium

2

Long term

3

Medium

6

Definite

Medium

– ve

Medium

3.2.3 Genetic impacts on wild stocks

Escape of fish from sea cages that may be established in South African is inevitable given that escape

from fish farms is a common event globally. Even in countries with advanced sea cage farming

industries and calm sheltered waters such as Norway, is it a regular occurrence with an estimated 1.5

million escaped salmon present in Norwegian fjords at any one time (Heuch et al. 2005). Given the

exposed nature of the South African coast and the abundance of large piscivores, regular escapes,

possibly of large numbers of stock as a result of cage failure or breach, is highly likely. Farmed fish that

are typically spawned from a limited number of brood stock, have reduced genetic diversity compared

to wild stocks, and will have undergone different selective pressures (will also have likely been artificially

selected for traits such as rapid growth). Genetically distinct escapees may interbreed or even out-

compete wild stocks, resulting in overall reductions on genetic diversity with resultant reductions in the

fitness of wild populations (Hershberger 2002, Naylor et al. 2005 Ford and Myers 2008).

The significance of genetic impacts of escaped farm fish on wild stocks is largely determined by the

extent of genetic differentiation between farmed and wild stocks, the quantity of escapees compared to

the size of the wild stock, and the survival and reproductive success of escaped fish (Falconer and

Mackay 1996). The risk of genetic contamination is therefore accentuated by the collapsed status of

many South African linefish species (that will likely be used in cage farming). The relatively small wild

population sizes of exploited South African linefish species such as kob, geelbek and white steenbras,

means that these native populations could be swamped by fish farm escapees resulting in potential

further loss of genetic diversity (fishing mortality has probably already decreased the genetic variation

present in wild populations). Algoa Bay, with its long sandy beaches, productive surf zones and two

large estuaries, appears to be important habitat for the overexploited dusky kob (P. Cowley, SAIAB,

personal communication, see Hutchings et al. 2013). The same is true for other potential culture species

with overexploited native populations in Algoa Bay such as the silver kob and white steenbras

(Lithognathus lithognathus). DAFF has developed “Genetic Best Practice Management Guidelines for

Marine Finfish Hatcheries in South Africa” that recommend maintaining an effective broodstock

population size of 30-150 individuals sourced from the area in which grow-out will take place, and also

that broodstock are rotated between hatcheries and regularly replaced to ensure an effective

population size of >100 (DAFF undated). The Marine Finfish Farmers Association of South Africa

Environmental Impact Information Document includes similar recommendations, but also recommends

reproductive sterility as the future key to eliminating the genetic impact of escaped fish on wild stock

(MFFASA 2010).

Until reproductively sterile fingerlings are available for fish cage farming in South Africa, the potential

genetic impacts of escapees remains a threat to wild stocks. The impact would be across the natural

range of the affected species, the intensity of the impact would be high and irreversible (within the

foreseeable future but not over evolutionary timescales), resulting in an overall high significance and

negative impact in the absence of mitigation (Table 4). Maintaining a large effective population size and

27

genetic homogeneity between cultured and wild stock is potentially a very effective mitigation measure

and the overall significance is assessed as low with the successful implementation of mitigation.

Independent monitoring of brood stock rotation, breeding programmes and cultured stock genetic

diversity may, however, be required to ensure that mitigation is effective, as future farmers would face

a conflict of interest in that they would be tempted to selectively breed for traits that enhance stock

productivity (stock improvement). The impact rating for Algoa 5 after mitigation is considered

“Medium” significance as opposed to “Low” significance in the case of Algoa 1. This is a result of the

Algoa 5 site been significantly more exposed to winter storms and the probability of escapes due to cage

system failure is considered higher. Essentially the effectiveness of the two mitigation measures to

reduce escapes and recover escapees is considered to be lower at the Algoa 5 site than at the Algoa 1

site.

Table 4. Assessment of the possible impacts of genetic contamination of wild stocks with escapees from finfish cage culture operations on the proposed Algoa 1 ADZ.


Without

mitigation

Regional

2

High

3

Long term

(ongoing,

irreversible)

3

Very High

8

Possible

High

– ve

Low 1


Maintain genetic compatibility (similar levels of variation) between wild and cultured stock by implementing the “Genetic Best Practice Management Guidelines for Marine Finfish Hatcheries” developed by DAFF and ensure adequate genetic monitoring.

Reduce the number of escapees by maintain cage integrity through regular maintenance and replacement and training of staff.

Develop and implement recovery procedures should escapes occur. Optional mitigation measures:


With

mitigation

Regional

2

Low

1

Long term

3

Medium

6

Improbable

Low

– ve

Low1

1. Confidence is low as monitoring would be required to determine any changes in genetic diversity in wild stocks

due to the influence of escaped culture stock. Furthermore, negative impacts of reduced genetic diversity will only

be reflected in the demographics of wild stocks should the population face a threat and reduced environmental

fitness is exposed.

28

Table 5. Assessment of the possible impacts of genetic contamination of wild stocks with escapees from finfish cage culture operations on the proposed Algoa 5 ADZ.


Without

mitigation

Regional

2

High

3

Long term

(ongoing,

irreversible)

3

Very High

8

Probable

Very High

– ve

Low 1


Maintain genetic compatibility (similar levels of variation) between wild and cultured stock by implementing the “Genetic Best Practice Management Guidelines for Marine Finfish Hatcheries” developed by DAFF and ensure adequate genetic monitoring.

Reduce the number of escapees by maintain cage integrity through regular maintenance and replacement and training of staff.

Develop and implement recovery procedures should escapes occur. Optional mitigation measures:


With

mitigation

Regional

2

Low

1

Long term

3

Medium

6

Probable

Medium

– ve

Low1

1. Confidence is low as monitoring would be required to determine any changes in genetic diversity in wild stocks

due to the influence of escaped culture stock. Furthermore, negative impacts of reduced genetic diversity will only

be reflected in the demographics of wild stocks should the population face a threat and reduced environmental

fitness is exposed.

3.2.4 Chemical pollution arising from finfish cages

Disinfectants, antifoulants and therapeutic chemicals (medicines) are typically used in sea cage fish

culture. These chemicals are often directly toxic to non target organisms and may remain active in the

environment for extended periods (Kerry et al. 1995, Costello et al. 2001). Inappropriate use of

medicines may lead to resistance in pathogenic organisms. Some antifoulants contain trace metals

(usually copper) that can elevate environmental concentrations, can accumulate in sediments and, can

bioaccumulate in susceptible organisms (Costello et al. 2001). Some of the chemicals used historically

on fish farms to combat sea lice infestations were carcinogenic, whilst others are known to adversely

affect reproduction in salmonids (Staniford 2002, More & Waring 2001). Global bodies, (e.g. the World

Health Organisation and GESAMP), have highlighted the environmental and public health threats of

chemical use on fish farms (GESAMP: 1997, WHO: 1999 cited in Staniford 2002). Due to these concerns,

the salmon farming industry is moving away from the use of antibiotics and organophosphates, but

numerous other potentially hazardous chemicals such as synthetic pyrethroids, artificial colorants,

antifoulants, and antiparasitics are still a serious concern (Staniford 2002). Future South African finfish

cage farms will almost certainly need to use chemicals to protect infrastructure and treat stock; the

MFFASA code of conduct recommends avoiding hazardous chemical use, minimizing the use of

agricultural, veterinary and industrial chemicals and adherence to legal requirements when these are

required (MFFASA 2010).

29

The effects of chemical pollution arising from fish cages on Algoa 1 and Algoa 5 are anticipated to be

local, that is confined to Algoa Bay. The Mead et al. (2008) study assumed similar dispersal distances for

antibiotics as for dissolved nutrients (i.e. tens of km). Without mitigation however, the intensity and

overall significance of the impacts is regarded as medium in the case of Algoa 1 and high in the case of

Algoa 5 (taking the sensitivity of the receiving environment into account) (Table 6, Table 7). Wider

natural processes are anticipated to be altered e.g. breeding success of sea birds on Algoa Bay Islands

(and other high trophic level species like sharks, seals and dolphins) may be impacted, should chemicals

used in fish cage operations bio accumulate up food chains. Populations of several of the higher trophic

level species that occur and or breed within Algoa Bay are considered vulnerable or endangered in terms

of their IUCN conservation status. These include Humpback whales, three species of sharks (White,

Ragged tooth and Soupfin), Cape gannets and African penguins (important breeding colonies are found

on the Algoa Bay Islands), four species of Albatross (Wandering, Black-browed, Indian and Atlantic

yellow-nosed) and White-chinned petrels. The tendency for bioaccumulation of many chemicals used in

used in fish cage culture is not well researched, and in any case the biological availability and ecotoxicity

of these in the environment would be site, species and even population specific, hence the level of

confidence in the assessments is low-medium.

Table 6 Assessment of the possible impacts resulting from the use of chemical therapeutants and antifoulants in finfish cage culture operations on the proposed Algoa 1 ADZ


Without

mitigation

Local

1

Medium

2

Long term

(ongoing,

but

reversible)

3

Medium

6

Probable

Medium

– ve

Medium

(monitoring

required to

determine the

intensity of

impact)




Where effective, use environmentally friendly alternatives



Monitoring to determine the intensity of impact

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Probable

Low

– ve

Low

(effectiveness

of mitigation

not known)

30

Table 7 Assessment of the possible impacts resulting from the use of chemical therapeutants and antifoulants in finfish cage culture operations on the proposed Algoa 5 ADZ


Without

mitigation

Local

1

High

3

Long term

(ongoing,

but

reversible)

3

High

7

Probable

High

– ve

Medium

(monitoring

required to

determine the

intensity of

impact)




Where effective use environmentally friendly alternatives



Monitoring Optional mitigation measures:

Risk-averse site selection and avoidance of Algoa 5

With

mitigation

Local

1

Medium

2

Long term

3

medium

6

Probable

Medium

– ve

Low

(effectiveness

of mitigation

not known)

3.2.5 Entanglement of cetaceans and other species

Sporadic entanglement of marine mammals and occasionally other species such as turtles and birds in

fish cage infrastructure has been reported internationally (Kemper & Gibbs 2001, Wuersig 2001,

Wuersig & Gailey 2002). Entanglement of cetaceans in fishing gear is a common occurrence with an

estimated 300 000 mortalities annually (Read and Fernades 2003). Off the South African coast, a large

and growing population of southern right whales occurs, this species along with Humpback and Brydes

whales and large pods of common and other dolphin species inhabit the inshore waters along the Cape

coast. Southern right whales frequently become entangled in static fishing gear such as west coast rock

lobster traps off the SW Cape and it appears that accidental entanglement is a real risk with future

extensive fish cage developments anywhere along the South African coast.

Six species of cetaceans are regularly seen in Algoa Bay; these include southern right whales (Eubalaena

australis), humpback whales (Megaptera novaeangliae), Bryde’s whales (Balaenoptera brydei), Indian

Ocean bottlenose dolphins (Tursiops aduncus), Indo-Pacific humpback dolphins (Sousa chinensis), and

longbeaked common dolphins (Delphinus capensis). The zoogeography of these species has been the

focus of a recent comprehensive study that analysed distribution patterns collected from over a year’s

31

worth of boat-based observations in relation to various physical and behavioural variables e.g. distance

from shore, bottom depth and type, season, sea state, foraging, travelling, resting etc (Melly 2011). This

study identified key habitats for each species and highlighted the importance of Algoa Bay as a breeding

and nursery area for southern right whales and as a potentially important nursery area and migration

route for humpback whales. The distribution patterns of the other four cetacean species were thought

to be linked primarily to prey distributions. A key habitat area for southern right whales, humpback

dolphins and bottlenose dolphins was identified between PE Port and Cape Recife adjacent to, but

mostly inshore of the proposed Algoa 1 ADZ (humpback dolphins in particular inhabit very shallow

coastal waters, an average of 6.6m, and most of the Algoa 1 ADZ is deeper than 25m). A long coastal

strip from just east of the Sundays River estuary mouth to Woody Cape was identified as a key habitat

for southern right and humpback whales and bottlenose dolphins. This area also lies inshore and to the

east of the proposed Algoa 5 ADZ, although humpback whales (along with Brydes whales and common

dolphins) were associated with deeper water i.e. a more offshore group whose distributions may more

frequently overlap with the proposed ADZs.

The proposed Algoa ADZs therefore, do not appear to overlap with important cetacean habitats within

Algoa Bay as identified in the Melly (2011) study, but it must be acknowledged that Algoa Bay as a whole

appears to be an important cetacean habitat, and that these are highly mobile animals whose

distributions may well show extensive temporal variation (that leads to overlap with the proposed

ADZs). Given the rarity of accidental entanglements in mariculture operations internationally and the

encouraging statistic of zero cetacean entanglements during the pilot sea cage project undertaken in

Algoa Bay, accidental entanglement in sea cage infrastructure is assessed as low to medium overall

significance (Table 8). Essential mitigation measures do, however, include the establishment of a rapid

response protocol to deal with entanglements. Acoustic and other deterrent devices have been shown

to be ineffective in the long term due to behavioural conditioning, and are not recommended mitigation

(Petras, 2003 in McCord et al. 2008).

Cetaceans and other marine animals may be able to avoid lethal effects associated with entanglement in

fish cage infrastructure, but the mere presence of sea cages may well adversely affect habitat use and

may have chronic negative effects on populations (as well as ecotourism activities) (Wuersig and Gailey

2002). Work boats travelling between PE or Coega Port and the proposed ADZs will need to travel

through important whale areas daily, possibly leading to disturbance, particularly of mother-calf pairs

(also increasing the risk of a boat strike). As fish cage development on the proposed ADZ increases (i.e.

as more cages are moored) so does the potential interference with natural cetacean movements and

feeding. Due to the expected relatively small increase in boat traffic due to future ADZ development,

and the relatively small sea area that would be occupied by the Algoa ADZs, the overall significance of

these impacts is assessed as low overall significance (Table 9).

32

Table 8 Assessment of the possible impacts on cetaceans resulting from accidental entanglement in finfish cage culture infrastructure on the proposed Algoa 1 and Algoa 5 ADZs


Without

mitigation

Local

1

Medium

2

Long term

(ongoing,

but

reversible)

3

Medium

6

Probable

Medium

– ve

Medium

(probability of

entanglement

inferred from

reported

studies

elsewhere)


Do not locate ADZs in important cetacean habitats (fortuitously this is the case).

Ensure all mooring lines and nets are highly visible (use thick lines and bright antifoulant coatings).

Keep all lines and nets tight through regular inspections and maintenance.

Ensure that mesh size on primary and secondary nets does not exceed 16 cm stretched mesh, use square mesh.

Establish a rapid response unit to deal with cetacean entanglements (collaboration with the South African Whale Disentanglement Network)

With

mitigation

Local

1

Medium

2

Long term

3

Medium

6

Possible

Low

– ve

Medium

(effectiveness

of mitigation in

local context is

not known)

Table 9 Assessment of the possible impacts on cetaceans resulting from alterations in habitat use or migration patterns due to finfish cage culture operations on the proposed Algoa 1 and Algoa 5 ADZs


Without

mitigation

Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Probable

Low

– ve

Medium

(Monitoring

required to

confirm

potential

impacts on

cetacean

habitat use)


Keep a log of all cetaceans recorded in the vicinity of fish farms including behavioural observations

Establish a cetacean monitoring programme in order to detect potential changes in cetacean habitat use in the broader Algoa Bay

With

mitigation Local

1

Low

1

Long term

3

Low

5

Probable

Low

– ve

Low

33

3.2.6 Interactions with piscivorous marine animals

Piscivorous seals, dolphins, sharks, fish and birds are frequently attracted to the large concentrations of

fish and or food in sea cages (Wuersig and Gailey 2002, Vita et al. 2004, Kloskowski 2005). Their

attempts to get at the stock induce a stress response (and consequent decreased growth rates and

resistance to disease) in the cultured fish and can damage nets, allowing fish to escape. The predators

themselves may also become entangled in sea cage nets with potentially fatal consequences. The most

effective and common response by farmers is to install top and curtain anti predator nets, although

farmers will also shoot problem animals (which is usually illegal), or use acoustic deterrents (Pemberton

& Shaughnessy 1993, Wickens 1995, Beveridge 1996, Wuersig & Gailey 2002). In the case of top

predators, which are frequently relatively rare, lethal reactions by farmers to predation attempts may

prove unsustainable, whilst acoustic deterrent devices may damage marine mammal’s hearing and

interfere with navigation (Wuersig and Gailey 2002).

Seals, sharks and predatory sea birds are abundant within Algoa Bay and interactions with finfish sea

cages are likely. During the pilot project undertaken in Algoa Bay, the cages were seen to act as FADS

and an incident did occur when two small ragged tooth sharks managed to enter a cage (Nell & Winter

2009). Due to the extensive foraging range of most large marine predators, however, interactions

cannot be completely mitigated by site selection away from colonies and the overall significance of the

impact is assessed as Low at the Algoa 1 site (Table 10). The proximity of Algoa 5 to the seal and bird

Islands and within known feeding areas for some piscivores (e.g penguins, gannets, dolphins- see

Hutchings et al. 2013), suggests that potential impacts will be more significant at this site than at the

Algoa 1 site and are assessed as Medium after effective mitigation.

Table 10 Assessment of the possible impacts resulting from piscivorous marine animals interacting with finfish cage culture operations on the proposed Algoa 1 ADZ


Without

mitigation

Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Probable

Low

– ve

Medium

(Monitoring

required to

confirm

frequency of

interactions)







Implement mitigation measures as for entanglement impacts (Table 8).


Maintain a record of all interactions with piscivores as per recommended EMPr (see section 0)

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Probable

Low

– ve

Low 1

34

1:Monitoring required to assess the effectiveness of mitigation.

Table 11 Assessment of the possible impacts resulting from piscivorous marine animals interacting with finfish cage culture operations on the proposed Algoa 5 ADZ


Without

mitigation

Local

1

High

3

Long term

(ongoing,

but

reversible)

3

High

7

Probable

High

– ve

Medium

(Monitoring

required to

confirm

frequency of

interactions)







Implement mitigation measures as for entanglement impacts (Table 8).


Maintain a record of all interactions with piscivores as per recommended EMPr (see section 0) Recommended l mitigation measures:

Risk-averse site selection and avoidance of Algoa 5

With

mitigation

Local

1

Medium

2

Long term

3

Medium

6

Probable

Medium

– ve

Low(Monitoring

required to

assess the

effectiveness of

mitigation)

3.2.7 User conflict

Due to security concerns, fish farms will need to exclude other users from what was previously public

sea space. As a result of the lack of sheltered sea space off South Africa’s coast, most of the areas

suitable for cage culture are already heavily utilised for fishing, ecotourism and other commercial and

recreational activities. Indeed, the proposal by Irvin & Johnson to develop a 3 000 ton fish farm in

Mossel Bay met fierce resistance from amongst others, ecotourism operators. Several important

commercial fisheries also operate in areas where fish cage culture may be viable (particularly chokka

squid, small pelagic, shark longline and linefish); resistance from these bodies to the declaration of

exclusive ADZs is likely. In the United States of America, a large and politically powerful body of

recreational fishers have also resisted mariculture developments that they perceive as detrimental to

their sport (Harvey & McKinney 2002).

35

The description of the affected environment report (Hutchings et al. 2013) identified potential conflict

resulting from the development of the Algoa ADZs with four types of recreational marine activities,

namely non-motorised water sports, recreational SCUBA divers, yacht sailing and recreational boat

anglers. The overall significance of direct impacts on these user groups is assessed in (Table 12 to Table

17) and ranges from very low (Algoa 5) to High (Algoa 1). Two commercial fisheries, namely squid and

shark longline will potentially be adversely affected by the development of fish cages on Algoa 1 and/or

Algoa 5 as these areas overlap with important fishing grounds. In light of the cumulative impacts on

available fishing grounds for these sectors within Algoa Bay, these impacts are rated as medium, with no

obvious effective mitigation measures other than reducing the size of the proposed ADZs (consultation

may help reduce conflict but will not compensate for lost grounds).

A further user group conflict is identified in the case of Algoa 5, in that this proposed ADZ falls within the

proposed Addo Elephant Marine Protected Area. SANParks, the main proponents of this MPA, have

indicated that they do not support the concept of commercial mariculture within MPAs and that the

declaration of Algoa 5 ADZ would compromise the inclusion of this area within the proposed MPA. This

negative impact on the conservation objective is rated as High significance as it both compromises the

functioning and management of the proposed MPA and also sets a precedent for MPAs elsewhere in

South Africa. No effective mitigation exists, other than the No-go option for Algoa 5.

The potential indirect impact on recreational and commercial line fisheries should finfish cage farming

lead to outbreaks of diseases and parasites amongst wild stocks, or to reduced environmental fitness

due to genetic contamination of wild stocks, is the same as the assessment for these impacts (i.e. High

to very High see Table 2 &Table 4).

Table 12 Assessment of the possible impacts on recreational water sport participants resulting from finfish cage culture operations on the proposed Algoa 1 ADZ


Without

mitigation

Local

1

Medium

2

Long term

(ongoing,

but

reversible)

3

Medium

6

Possible

Low

– ve

Low

(Changes in

large sharks

distribution

patterns in

response to

development

unknown)


Implement mitigation measures as per Table 10 to try reduce interaction with large marine piscivores.

Monitor large shark movement patterns before and after ADZ development as per recommended EMPr monitoring components (see section 0).

With

mitigation Local

1

Medium

2

Long term

3

Medium

6

Possible

Low

– ve

Low

(Effectiveness

of mitigation

unknown)

36

Table 13 Assessment of the possible impacts on recreational water sport participants resulting from finfish cage culture operations on the proposed Algoa 5 ADZ


Without

mitigation

Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Improbable

Very Low

– ve

Low

(No prior

knowledge of

how large

sharks may

alter

distribution

patterns in

relation to ADZ

development)


Implement mitigation measures as per Table 10 to try reduce interaction with large marine piscivores.

Monitor large shark movement patterns before and after ADZ development as per EMPr monitoring components (see section 0).

With

mitigation

Local

1

Low

1

Long term

3

Low

6

Improbable

Very Low

– ve

Low

(Effectiveness

of mitigation

unknown)

Table 14 Assessment of the possible impacts on recreational SCUBA divers resulting from finfish cage culture operations on the proposed Algoa 1 ADZ.


Without

mitigation

Local

1

High

3

Long term

(ongoing,

but

reversible)

3

High

7

Probable

High

– ve

Low

(Potential

dispersal

distances of

organic and

chemical

wastes from

ADZs require

modelling and

monitoring)


Implement mitigation measures as per Table 3 and Table 6 to try reduce organic and chemical pollution.

Implement recommended benthic monitoring and adaptive management EMPr monitoring components (see section 0).

With

mitigation

Local

1

Medium

2

Long term

3

Medium

6

Probable

Medium

– ve

Low

(Effectiveness

of mitigation

unknown)

37

Table 15 Assessment of the possible impacts on recreational SCUBA divers resulting from finfish cage culture operations on the proposed Algoa 5 ADZ


Without

mitigation

Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Improbable

Very Low

– ve

Low

(Potential

dispersal

distances of

organic and

chemical

wastes from

ADZs require

modelling and

monitoring)


Implement mitigation measures as per Table 3 and Table 6 to try reduce organic and chemical pollution.

Implement recommended benthic monitoring and adaptive management as per EMPr monitoring components (see section 5).

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Improbable

Very Low

– ve

Low

(Effectiveness

of mitigation

unknown)

Table 16 Assessment of the possible impacts on yacht sailing and recreational boat anglers resulting from finfish cage culture operations on the proposed Algoa 1 and Algoa 5 ADZs.


Without

mitigation

Local

1

Low

1

Long term

(ongoing,

but

reversible)

3

Low

5

Probable

Low

– ve High


Install navigational markers and lights as required by SAMSA regulations.

Include position of ADZs on navigational charts.

Ongoing consultation with user groups to keep them informed of the ADZ developments.

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Improbable

Very Low

– ve

High

38

Table 17. Assessment of the possible impacts on commercial squid and longline shark fisheries resulting from finfish cage culture developments on the proposed Algoa 1 & Algoa 5 ADZs


Without

mitigation

Local

1

High

3

Long term

(ongoing,

but

reversible)

3

High

7

Definite

High

– ve

High


Reduce the size of the ADZs

With

mitigation

Local

1

Low

1

Long term

3

Low

5

Improbable

Very low

– ve

High

Table 18. Assessment of the possible impacts the proposed Addo elephant MPA resulting from finfish cage culture developments on the proposed Algoa 5 ADZ.


Without

mitigation

Local

1

High

3

Long term

(irreversible)

3

High

7

Definite

High

– ve

High


No go option

39

4 Recommended Algoa Bay ADZ development and

management

Given the predicted medium and high significance impacts on marine vertebrates, particularly on sea

birds, seals, sharks and cetaceans associated with the St Croix and Bird islands, as well as the position

within a proposed MPA (thus contrary to conservation objectives) the development of Algoa 5 as an ADZ

is not recommended. The economic viability of this site, due to its exposed position and distance from

port is also questionable. Algoa 1 is far more favourable from a mariculture industry perspective, and

impacts on large marine fauna are rated slightly lower than for Algoa 5. Predicted impacts due to

organic and chemical waste generation, disease introduction, and genetic contamination of wild stocks

are assessed as being of a similar significance at both sites, and user conflict, particularly with the

established fisheries (specifically squid) and recreational water users, are higher for Algoa 1.

Britz (2007) identified marine finfish farming as the South African Aquaculture sector with the highest

growth potential over the 10-15 year timeframe (projected production was as high as 40 000 tons). This

study did, however, highlight the lack of sufficient sheltered sea area as the major hurdle to the

development of this industry. The establishment of ADZs for finfish cage culture (including the 2011 SEA

and this EIA process) were the logical steps taken by government to try and alleviate this obstacle to the

development of a South African sea cage finfish industry. Issues identified during the 2011 SEA and this

EIA process, namely: the linear, very exposed coastline (all countries that are major fish cage culture

producers have glaciated coastlines or extensive sheltered sea space); high levels of existing

development and use of the little available sheltered sea space; vulnerability of important wild fish

stocks to potential disease impacts; and abundance of large and/or endangered marine vertebrate

fauna that are common in inshore coastal waters, indicate that “inshore” sea cage culture may not be

viable in South Africa. We recommend that the future of finfish mariculture development should focus

on shore-based, recirculating systems that appear to carry lower environmental and economic risks.

The technology for this already exists, and successful, commercial scale, shore-based finfish farms are

already in operation in the East London IDZ. Alternatively the research and development of “offshore”

cage technology (including robust submersible cage designs and automatic feeders etc.) that can be

deployed in areas with potentially lower potential environmental impacts and user conflict may be a

more viable future for this industry in South Africa.

Should the decision making authority decide to grant environmental authorization for the development

of the Algoa 1 ADZ however, a comprehensive Environmental Management Programme (EMPr) must be

developed and implemented for each fish cage development within the ADZ. These EMPrs must require

independent monitoring of sufficient indicators in order to detect and quantify any of the environmental

impacts described above, and must specify thresholds of concern which require remedial action. It is

strongly recommended that should either of these two ADZs be proclaimed, development of the zone is

phased in so that cumulative impacts can be detected as they arise, and adaptive management

implemented. The potential scale of fish cage farming on either of these sites is massive, with annual

potential production greatly exceeding South Africa’s wild capture fisheries. There is a high degree of

40

uncertainty as to many of the potential environmental impacts of finfish cage culture on these sites (as

assessed above). Certainly the ability of the environment to assimilate wastes produced by commercial

scale farms is unknown and difficult to predict or model. Even when current profiling data becomes

available for these sites, much more explicit planning data would be needed on future farm

developments and operating procedures, in order to model cumulative nutrient loading and waste

plume dimensions. Potential impacts on marine vertebrates, including wild fish populations, bird and

mammal piscivores and cetaceans are also very difficult to predict. We reiterate that should either ADZ

be declared, on-going, comprehensive environmental monitoring and adaptive management concurrent

with a phased development of the ADZ must be implemented. It is recommended that no more than

three operators should be approved for an initial pilot phase, with a total annual production for the ADZ

not exceeding 1 000 tons in the first year. Should monitoring reveal acceptable impacts as defined by

the environmental quality objectives, indicators and performance measures, the competent authority

may decide to authorise an increase in production from pilot phase to full commercial scale (a maximum

of 9000 tons per ADZ ) over at least a three year period, provided resource quality objectives are

maintained. Further development and expansion (addition of more operators and/ increase in

production for established farms) should be dependent on acceptable environmental quality objectives

as revealed by ongoing monitoring.

41

5 Recommended marine monitoring components of an

EMPr for the Algoa ADZs

As part of the Environmental Authorisation process, an essential component is the submission of an

Environmental Management Programme (EMPr) (previously called an Environmental Management Plan

or EMP) (Regulation 33 in the EIA regulations; R543 of 2010). The aim of such a Programme would be to

document and plan the management approach that will best achieve the avoidance and minimisation of

potential environmental impacts in the construction, operation and decommissioning phase of the ADZ.

The Environmental Impact Assessment Guideline for Aquaculture in South Africa provides a framework

for such an EMPr and highlights relevant components required for monitoring of aquaculture facilities

(National Environmental Management Act, 1998 [Act No. 107 of 1998]: General Notice 101 of 2013).

It is recommended that Environmental Management Programmes are developed for the ADZ in its

entirety and for each individual fish farm within the ADZ. The EMPr for the ADZ will allow for the

management of the cumulative effects of all farms holistically. This EMPr should include all

recommendations listed in the Environmental Impact Assessment Report and conditions outlined in the

Environmental Authorisation.

EMPr’s for each farm on the other hand, will allow for more efficient and precise management at the

scale of individual farms. This will in turn provide farmers with the opportunity to custom manage their

facilities and allow designated authorities to better manage compliance. EMPr’s for each farm should

be formulated so that they are compatible, supportive and facilitative of the EMPr for the ADZ within

the limits of the Environmental Authorisation. Environmental objective limits and indicators will need to

be developed and specified for each EMPr.

A key component of the proposed project and its associated EMPr’s is the management and monitoring

of potential impacts on the environment. As discussed in Section 4 above, it is recommended that the

proposed development be phased in; this will allow for an adaptive management strategy that can be

formulated and adjusted based on real-time environmental monitoring data as the project evolves and

production increases in accordance with acceptable environmental thresholds and South African

aquaculture guidelines (NEMA, 1998 [Act No. 107 of 1998]: General Notice 101 of 2013).

An efficient and detailed monitoring programme that will guide and inform an adaptive management

strategy is therefore an essential requirement. In order to manage the programme, a Monitoring Forum

that comprises stakeholders from DAFF, the mariculture industry, Cape Nature, independent scientists

and community members should be established. An independent company(s) should then be managed

and tasked by the Monitoring Forum to conduct environmental monitoring at each individual fish farm

within the ADZ and for the ADZ and Algoa Bay area at large. This will ensure objectivity and

transparency, and facilitate the requirements and goals of the individual EMPr’s.

Section 21 of the EIA guidelines for aquaculture in South Africa is of particular relevance in isolating

relevant components for an aquaculture monitoring programme (NEMA, 1998 [Act No. 107 of 1998]:

42

General Notice 101 of 2013). These guidelines emphasise that production volumes are often limited by

in situ environmental constraints (as opposed to market & technological constraints) and that the

activity must be accommodated sustainably in accordance with the capacity and abilities of the natural

resources and ecological services of the receiving environment (NEMA, 1998 [Act No. 107 of 1998]:

General Notice 101 of 2013). Operations must conduct themselves within sustainable production

capacities to prevent environmental degradation (NEMA, 1998 [Act No. 107 of 1998]: General Notice

101 of 2013).

Monitoring data may therefore be collected (FAO 2009):

as part of an EIA generated Environmental Management Programme (EMPr);

in compliance with some form of code of practice;

for the information of the farmer in support of husbandry;

by regulatory authorities as part of enforcement;

by regulatory authorities as part of monitoring in the wider environment.

It is recognised that components of a monitoring programme for each EMPr may vary and overlap,

depending on whether the EMPr is for an individual farm or for the entire ADZ, or depending on the

individual characteristics and requirements of each individual farm. In essence, each fishfarm within an

ADZ should have their own monitoring programme for their respective EMPr that is project specific and

is compiled as and when they develop. This should include for example farm specific monitoring and

record keeping of animal husbandry, stock health, feeding programmes, water quality within and

adjacent to cages, sediment sampling in the immediate vicinity of the farm cages and plans to deal with

escapees and predators.

Components of a monitoring programme for an ADZ EMPr, however, would include monitoring for

wider spatial and cumulative impacts of farms including monitoring further afield and at control sites so

that the overall ADZ footprint can be determined. In addition, monitoring for the ADZ EMPr would

include studies of disease and parasites and genetic variability within wild stocks, and status of

ecosystem indicators further afield (e.g. bird nesting success on islands, cetacean use of important

feeding and breeding habitats, habitat use by fish, cetaceans and sharks via telemetry studies). Many of

these programmes will need to be collaborative with existing studies in Algoa Bay. All farmers should

contribute to an ADZ monitoring trust that provides funding for the monitoring component of the ADZ

EMPr, with assistance from the state (DAFF & DEA, Provincial Nature Conservation Department etc).

Based on the EIA aquaculture guidelines for South Africa (NEMA, 1998 [Act No. 107 of 1998]: General

Notice 101 of 2013), and the Basic Assessment Report compiled for Irvin & Johnson’s Proposed

Aquaculture Project, Mossel Bay (CCA Environmental 2008), recommended components for monitoring

that would provide the necessary information for an EMPr are provided in Table 19.

Table 19. Recommended monitoring components required by an EMPr for individual farms and/or for an ADZ. Should the proposed standard or target be regularly exceeded, an investigation by an independent EMPr committee is recommended and the efficacy of mitigation measures should be objectively assessed. if no other effective mitigation can be implemented, a reduction in stocked biomass is recommended until targets are consistently achieved.

Component and method for monitoring Required for

Environmental objectives

Proposed Standards/targets

Frequency of Monitoring

Farm EMPr ADZ EMPr

Establish an effective monitoring protocol to ensure that net integrities and supporting infrastructure are maintained. Each individual farmer should ensure that:

- The primary net is secured appropriately so that it is

kept taut and rigid (weighted) at all times; - There is adequate separation between the primary

and secondary nets even during strong currents and rough seas;

- Ropes and anchor lines are taut, especially after rough seas; and

- Ropes are routinely inspected for ware, especially after rough conditions, and replaced as and when required.

Prevent entanglement of cetaceans and piscovores. Prevent stock escape.

Zero system failure resulting in loss of

cage integrity. Fewer than 10

entanglements of any species per year and zero mortalities.

Surface infrastructure

– daily Subsurface

infrastructure- weekly or after storm events.

Establish an effective monitoring protocol to ensure culture-fish mortalities are quickly removed to minimise contamination and fluxes in waste production.

Minimise waste production and disease transfer.

Zero mortalities left in cages for a period exceeding 24 hours.

Daily

Establish an effective monitoring protocol to ensure feed waste is limited (i.e. prevent overfeeding by maximising the feed conversion ratio of cultured fish). Feeding regimes must ensure that direct feed wastage and above normal faecal and metabolite releases from fish are limited. Feed types and feeding rates should be recorded daily so that conversion efficiency can be calculated and monitored.

Minimise waste and organic pollution of water column and sediments.

Maximum of 1% of feed quantity uneaten (settling below cages)

Feeding rates to be recorded daily, pellet deposition monthly.

If predator deterrents are to be used, individual farmers Maximise Zero predation of Daily by farm

44

and the designated independent monitoring authority must closely monitor cetacean, seal, shark and seabird behaviour.

effectiveness of predator deterrents, minimize harmful effects of deterrents on predators.

cultured stock. Zero cases of physical harm to any predator caused by deterrents.

operator. During all

other monitoring activities by independent monitoring authority.

Information on cetacean, seal, shark and seabird occurrence (including incidence and behaviour) in Algoa Bay should be collected before and after the cages are introduced. This should involve the use of telemetry tracking as existing studies are underway.

Avoid alteration of natural feeding,

breeding and movement

behaviours of wild biota.

No detectable changes (outside of

natural) in large vertebrate

distributions over time that can be attributed to the presence of sea

cages.

As per existing monitoring

and acoustic tracking

programmes. A contribution to the running

costs of research projects

monitoring seals, sea

birds, cetaceans and sharks should be made for a period from

first development until at least 3

years after ADZ achieves

maximum capacity.

All marine vertebrate mortalities resulting either directly or indirectly from the development should be recorded. The

Minimise

impacts on high Target = zero mortalities.

Daily by farm operator.

45

programme should include guidelines for acceptable levels of mortality of non-cultured species (which may only be able to be developed over time) and where appropriate, mitigation

measures developed (e.g. modification of gears etc.).

trophic level vertebrates

Acceptable level to be determined by

EMPr advisory committee.

During all other

monitoring activities by independent monitoring authority.

Firstly, adhere to broodstock management guideline or species specific permit conditions that use precautionary

principles to reduce genetic impacts. This should be updated by genetic information gained from a monitoring programme

that assesses the genetic status of both farmed and wild populations in terms of genetic variability and compatibility

every three to five years. The interval of the monitoring programme can be adjusted based on the actual results and

changes within the breeding population (mortalities, replacements, etc.). The monitoring programme would

require that appropriate molecular markers and procedures (sampling, etc.) be developed for assessment of the species and populations under consideration. The responsibility for carrying out the monitoring and analysis of wild populations

should be that of the resource management authority (DAFF) in collaboration with farmers, as they should be responsible

for the profiling of their commercial broodstock/cultured stock.

Avoid reductions in

the environmental fitness of wild stocks due to

genetic contamination

by cultured stock

No detectable change in natural genetic variation

within wild stocks. Maintain genetic

homogeneity between cultured

and wild stock.

At initiation of each species

stocked, thereafter every 3-5

years.

Each farmer must maintain a comprehensive and detailed register of the quantities of chemicals, antibiotics, antifoulants and hormones, etc. that are utilised.

Environmental concentrations should be measured at the edge of the zone of expected impact (50m from cage group)

in water and sediment samples – see benthic and water quality monitoring recommendations below.

Maintenance of water quality and aquatic

environment. Maintain health

of cultured stock. Minimise potential spread

of disease

All concentrations of potentially

dangerous chemical additives as measured at the edge of the zone of expected impacts (50m) to lie within appropriate safety

Register of chemical use –

continuous and ongoing.

Measurement of

environmental concentrations

: as per

46

threat to native stocks.

limits for humans & within acceptable

levels for non-target organisms

such that they are not negatively

impacted.

benthic and water quality monitoring described

below.

Establish a traceability protocol of the cultured fish and its products.

Ensure that cultured fish

products do not act as a cover for the illegal sale of wild stock (e.g.

undersize fish)

100% traceability of cultured fish

product

Continuous as required by

marine compliance officers, at processing, distribution and retail outlets.

Regular visual observations must be undertaken beneath each cage to assess the extent of pellet and faecal deposition beneath the cages. This may be impractical for many of the cages, as they will be moored in relatively deep water (>30 m). At the very minimum, cylinders should be suspended below each of the cages, close to the sea bed in order to

collect faecal and feed waste. This method allows the cylinders to be raised to the surface and inspected frequently.

Should these visual assessments identify excessive pellet accumulation the feeding strategy should be revised

accordingly.

Minimise waste and organic pollution of

water column and sediments

No standard, data to be used for

interpretation of benthic monitoring programme results.

For a two week period each month.

Develop a detailed benthic monitoring programme prior to commencement of the aquaculture activities. The monitoring programme should be initiated prior to stocking (the baseline surveys undertaken to date are sufficient to describe broad

spatial scale sediment characteristics and benthic macrofauna communities, final spatial scale monitoring should take place

in the vicinity of each proposed development) and include the

Minimise waste and organic pollution of

water column and sediments

PH > 7 Redox potential

>0mV Sulphide pore

water concentration from

top 2 cm of

Level 1 monitoring – biannually at

least 1 sampling event

within 1 month of peak

47

following:

Level 1 monitoring: Sediment physical and chemical characteristics: Indicators of sediment characteristics and

quality (e.g. particle size analysis, organic content, redox, pH, hydrogen sulphide concentration and the concentration of any potentially harmful chemicals that have been used in

operations including antifoulant constituents such as copper) should be monitored biannually. Samples should be

examined for the presence of macrobenthos. Sediment samples will need to be collected immediately adjacent to at

least four cages with the highest stocked biomass, on the North, East, South and West at the edge of expected impacts (50m from cage cluster) and at four control sites at least 1km

from the nearest cage in an area with similar physical characteristics (depth, sediment type etc). Sampling should

be conducted using a Van Veen type grab sampler as the water depths on the ADZs (20-60m) preclude extensive

scientific diving. In addition, video or photographic surveys beneath and adjacent to fish cages should be undertaken biannually to assess accumulation of uneaten pellets and

faeces beneath the cages, as well as the presence of bacterial mats and black anoxic sediments. These can be conducted

using remotely deployed cameras where water depth limits scientific diving.

Level2 monitoring: Biological monitoring: Monitoring should be undertaken on an annual basis to record changes to the macro-benthic community structure underlying each farm and the extent of this impact. It is recommended that grab

sampling be conducted directly adjacent to four of the most densely stocked cages and at 50m in four directions (North,

East, South and West) from the cage cluster of each farm

sediment < 1500 µM.

Changes in particle size and organic

content are expected but

records must be kept to monitor recovery with

fallowing. Macrobenthos must occur in

sediments within the zone of

expected impacts. At the edge of the zone of expected

impacts, in addition to the above requirements macrobenthic communities

should not differ from the baseline or control sites as

determined by multivariate

analysis (MDS. ANOSIM

and/PERMANOVA tests, abundance-biomass curves in

PRIMER or equivalent) using a

biomass being attained. Level 2

monitoring: annually within 1

month of peak biomass being attained. The frequency of

level 2 monitoring

may be reduced after three years of

annual monitoring,

provided production rates are

stable and benthic

environmental health is

acceptable.

48

within an ADZ, rather than diver operated core-sampling beneath cages due to depth constraints and to allow for

continuity in the methods used by the baseline surveys of Algoa 1 & Algoa 5 (see Hutchings et al. 2013). Biological samples should be identified, counted and weighed, and

would allow for quantitative assessments of the benthic biota over time (i.e. k-dominance curves). The same method should be repeated at four suitable control sites at least at least 1km

from the nearest cage in an area with similar physical characteristics (depth, sediment type etc). At least three

control sites sufficiently far away from the ADZ yet still within Algoa Bay and with similar abiotic characteristics to the ADZ (sediment grain size, depths etc) should be sampled at the

same time as each biological survey. The number of replicates at each station is determined by the size of grab sampler

used: when using a grab sampler with a mouth opening of 0.1m2 two replicates per station, when using a smaller grab of

0.02m2, 5 replicates per station are required

Before After Control Impact design (BACI).

Shannon-Weiner index of diversity

should be equivalent to

control sites or remain >3

If excessive build-up of benthic organic waste is observed, sufficient time for these sites to return to their natural baseline state (i.e. state prior to the ADZ) should be allowed. If need be, cages should be moved periodically, in a rotational scheme, to allow for fallow periods where the bottom can recover and benthic organic waste can be more evenly distributed within an ADZ. Sites should be monitored for recovery using physical, chemical and biological indicators.

Minimise excessive organic

pollution of sediments.

To be based on the limits of the above benthic monitoring

program

As for the above benthic

monitoring program

Develop a detailed water column quality monitoring programme (temperature, pH, dissolved oxygen, ammonia, nitrite, at a minimum) within cages, at the edge of expected impacts (50m from cage groups) and at control sites at least 10km from the nearest cage.

Maintain water quality at

acceptable levels

*Within Cages: pH 7.5-8.5, dissolved oxygen above 4.5

mg.L-1 (above approx. 80% saturation),

Within cages:weekly.

50 m from cages and

control sites: initially

49

ammonia (NH3-N) <0.02 mg.L-1,

Nitrite (NO2) <0.1 mg.L-1

Between Cages within 50m: pH

7.8-8.3, dissolved oxygen above 80%

saturation. ammonia (NH3-N)

<0.01 mg.L-1, Nitrite (NO2) <0.05

mg.L-1

Within ADZ:

For Algoa Bay & Control Sites:

Not higher than the 80th percentile of background.

levels

monthly until 1month after peak biomass

is attained and then as per

Level 1 benthic monitoring

provided peak biomasss does not increase(bi

annual)

Monitor the caged fish daily during feeding to ensure a healthy fish stock.

Pre-emptive loss of stock to

allow for adaptive

management

Target = Zero loss. Monitoring

committee to decide on standard.

Daily during feeding

Develop a protocol to monitor escapes.

Minimise potential

genetic impacts. Minimise

disease impacts

Target = Zero escapees.

Monitoring committee to

decide on standard.

Initiate monitoring when there are escapes

50

Establish an ongoing parasite/fish health monitoring programme of both wild and farmed fish, which includes pathogen identification and quantification. The parasite monitoring programme should be developed in collaboration with DAFF, as they should ultimately be responsible for carrying out the parasite monitoring on representative samples of wild populations.

Minimise and manage potential disease

outbreaks & impacts

Target = Zero infections and pathogens of

farmed species. persistent/regular outbreaks should be investigated by

independent monitoring

committee. No increase in disease

and pathogens above baseline

levels in wild stocks should be

acceptable.

Biannually

Ensure all fish being introduced into the sea-cages undergo a health exam by a suitably qualified veterinarian and are certified as disease free.

Preventative

stock loss. Disease control

Zero diseased fish introduced to

cages

Whenever stocking

At least every two years, facilities should be inspected by an aquaculture veterinarian to allow for monitoring of the health status of cultured stock.

Optimal growth rate. Disease

control.

Overall health of stock should be of

a suitable quality to promote and

ensure efficient growth rates of

particular species being cultured

Every two years

*The proposed water quality standard/target values for ammonia and nitrite within cages is based on available published values for salmon.

These values reflect a precautionary approach, although there is generally an inverse relationship between ammonia concentration and fish

growth rate. In addition, stressed fish due to elevated ammonia levels are more likely to be affected by disease. The sensitivity of different fish

species to these chemicals is likely to vary and the standard/targets should be adjusted depending on the species farmed and the natural

background levels in the environment.

6 References

Agius, C and Tanti, J (1997) Status of fish diseases in the Mediterranean. In T.W. Flegel and I.H. MacRae

(eds.), Diseases in Asian Aquaculture 111. Fish Health Section, Asian Fisheries Society, Manila

Berry, A W (1996) Aquaculture and sea loch nutrient ratios: a hypothesis. In K D Black (ed) Aquaculture

and sea lochs. Scottish Association of Marine Science, Oban http://www.mar.dfo-

mpo.gc.ca/science/mesd/he/lists/phycotoxins-1/msg00360.html

Beveridge, M.C.M. 1996. Cage Aquaculture. 2nd Edition. Fishing News Books, Oxford.

Bjorn P.A., Tveiten H., Johnsen H.K., Finstad B. and R.S McKinley (2002) Salmon lice and stress: effects on

reproductive performance in Arctic charr. In: Riehl M. and Struthers M. (eds.) Aquanet II,

Proceedings of the 2002 Annual Research Conference of Aquanet, September 14-17, 2002, Delta

Beausejour, Moncton, New Brunswick, Canada.

Black K.D., McLusky D.S., Nickell T.D., Pereira P.M. and P.M.F. Pereira (2004) Recovery of the sediments

after cessation of marine fish farm production. Aquaculture 235(1-4): 315-330.

Britz, P.J. 2007. A Study on the Status of Aquaculture Production and Trade in South Africa. Volume 2:

Growth Potential of the South African Aquaculture Industry and Recommendations for Sector

Development. A report for the Department of Trade and Industry produced by Enviro-Fish

Africa (Pty.) Ltd. 24p.

Brooks K.M., Mahnken C. and C. Nash. 2002. Environmental effects associated with marine netpen waste with emphasis on salmon farming in the Pacific Northwest. In: R.R. Stickney & J.P. McVey (eds); Responsible Marine Aquaculture CABI Publishing, New York.

Carroll M.L., Cochrane S., Fieler R., Velvin R. and P. White (2003) Organic enrichment of sediments from

salmon farming in Norway: environmental factors, management practices and monitoring

techniques. Aquaculture 226 (1-4): 165-180

CCA Environmental 2008. Final Basic Assessment Report for Irvin & Johnson’s Proposed Aquaculture

Project, Mossel Bay Prepared for: Department of Environmental Affairs and Tourism

Clark, B.M, Hutchings, K., Porter, S and K Sink 2011. Strategic environmental assessment: Identification

of potential marine aquaculture development zones for fin fish cage culture. Draft October

2011. Available at:

http://www.anchorenvironmental.co.za/index.php?option=com_content&view=article&id=27&I

temid=29

Christison K W and D B Vaughan (2009) The velvet assassins – Amyloodinium ocellatum potential disease

risk for captive marine fishes in South Africa. Oral presentation at the e 37th Annual Congress of

52

the Parasitological Society of Southern Africa (PARSA), 7–9 October 2008, Faculty of Veterinary

Science, University of Pretoria, Pretoria, South Africa. Jl S.Afr.vet.Ass. (2009) 80(2): 126–140

Clark, B. 2012. Environmental Impact Assessment for the development of marine aquaculture

development zones (ADZs) for fin fish cage farming in the sea off the Eastern Cape Province:

Report on issues identified in the Scoping Phase of the EIA and recommendations for the way

forward.

Costello, Grant, Davies, Cecchini, Papoutsoglou, Quigley and Saroglia. 2001: The control of chemicals

used in aquaculture in Europe. J. Applied Ichthyology, 17: 173 – 180.

DEA 2013, Government Gazette No. 36145 11 February 2013 Environmental Impact Assessment

Guideline for Aquaculture in South Africa. Compiled by E. Hinrichsen.

Department of Agriculture, Forestry and Fisheries (DAFF) undated. (Initial) Genetic Best Management

Practice Guidelines for Marine Finfish Hatcheries in South Africa.

http://www.daff.gov.za/doaDev/fisheries/21_HotIssues/MAPC/FinfishHatcheryManagementPro

tocoll.pdf

FAO. 2009. Environmental impact assessment and monitoring in aquaculture. FAO fisheries and

aquaculture technical paper. No. 527. Rome, Italy. 675pp.

FAO 2012 Cultured Aquatic Species Information Programme Argyrosomus regius(Asso, 1801).

http://www.fao.org/fishery/culturedspecies/Argyrosomus_regius

Falconer, D.S., Mackay, T.F.C., 1996: Introduction to quantitative genetics. Harlow, Essex: Longman

Felsing M., Glencross B., Telfer T., and Felsing B. (2005) Preliminary study on the effects of exclusion of

wild fauna from aquaculture cages in a shallow marine environment. Aquaculture 243: 159-174

Fernandes M & J. Tanner 2008. Modelling of nitrogen loads from the farming of yellowtail kingfish

Seriola lalandi (Valenciennes, 1833). Aquaculture Research 39: 1328-1338.

Ford, J.S. and R.A. Myers. 2008. A global assessment of salmon aquaculture impacts on wild salmonids.

PLoS Biology 6(2): e33. doi:10.1371/journal.pbio.0060033

GESAMP (1997) Towards the safe and effective use of chemicals in coastal aquaculture. Report No. 65.

FAO, Rome http://gesamp.imo.org/no65/index.htm

http://www.fao.org/docrep/meeting/003/w6435e.htm#concern

Gowen, R J and Ezzi, I A (1992) Assessment and production of the potential for hypernutrification and

eutrophication associated with cage culture of salmonids in Scottish coastal waters.

Dunstaffnage Marine Laboratory, Oban

Griffiths, M.H. 2000 Long-term trends in catch and effort of commercial linefish off South Africa's Cape

Province: snapshots of the 20TH century. South African Journal of Marine Science 22. 81-110

http://www.daff.gov.za/doaDev/fisheries/21_HotIssues/MAPC/FinfishHatcheryManagementProtocoll.pdf

http://www.daff.gov.za/doaDev/fisheries/21_HotIssues/MAPC/FinfishHatcheryManagementProtocoll.pdf

53

Hall-Spencer J and R Bamber 2007. Effects of salmon farming on benthic Crustacea. Ciencias Marinas

33(4): 353–366.

Harvey, W.D. and L.D. McKinney 2002. Recreational fishing and aquaculture: Throwing a line into the

pond. In: R.R. Stickney & J.P. McVey (eds); Responsible Marine Aquaculture CABI Publishing, New

York.

Hayward CJ, Bott NJ, Itoh N, Iwashita M, Okihiro M & BF Nowak 2007. Three species of parasites

emerging on the gills of mulloway, Argyrosomus japonicus (Temminck and Schlegel, 1843),

cultured in Australia. Aquaculture 265:27-40.

Hutching, K., Porter, S.N. & Clark, B.M. 2013. Marine specialist report. Marine Aquaculture Development

Zones for Fin Fish Cage Culture in the Eastern Cape: Description of the Affected Environment.

Anchor Environmental Consultants Report, compiled on behalf of the Department of

Agriculture, Forestry and Fisheries.

Hershberger, W K. 2002 Genetic changes in marine aquaculture species and the potential for impacts on

natural populations. In: R.R. Stickney & J.P. McVey (eds); Responsible Marine Aquaculture CABI

Publishing, New York.

Heuch P.A., Bjorn P.A., Finstad B., Holst J.C., Asplin L. and F. Nilsen (2005) A review of the Norwegian

‘National plan of Action against salmon lice on salmonids’: the effect on wild salmonids.

Aquaculture 246: 79-92.

Heggoey E., Vassenden G., and P. Johannessen (2004) Investigation of the marine biological

environmental conditions at a fish farm site in Radfjorden, Lindas Municipality, western Norway

in 2004 Vestbio 1: 35 pp. [English abstract]

Joubert C J H, Christison K W and H Kaiser 2009. An egg-laying rhythm in Diplectanum oliveri

(Monogenea:Diplectanidae), a gill parasite of dusky kob (Argyrosomus japonicus). Oral

presentation at the e 37th Annual Congress of the Parasitological Society of Southern Africa

(PARSA), 7–9 October 2008, Faculty of Veterinary Science, University of Pretoria, Pretoria, South

Africa. Jl S.Afr.vet.Ass. (2009) 80(2): 126–140.

Kemper, C.M. and Gibbs, S.E., 2001: Dolphin interactions with tuna feedlots at Port Lincoln, South

Australia and recommendations for minimising entanglements. Journal of Cetacean Research

and Management 3(3): 283-292.

Kempf M., Merceron M., Cadour G., Jeanneret H., Mear Y. and P. Miramand (2002) Environmental

impact of a salmonid farm on a well flushed marine site: II Biosedimemtology. Journal of Applied

Ichthyology 18: 51-60.

Kerry J., Hiney M., Coyne R., NicGabhainn S., Gilroy D., Cazabon D. and P. Smith (1995) Fish feed as a

source of oxytetracycline-resistant bacteria in the sediments under fish farms. Aquaculture 131:

101-113.

54

Kloskowski 2005 - Kloskowski J. 2005. Otter Lutra lutra damage at farmed fisheries in southeastern

Poland, I: an interview survey. Wildlife Biology 11(3): 201-206.

Krkošek, M., J.S. Ford, A. Morton, S. Lele, R.A. Myers, and M.A. Lewis. 2007. Declining wild salmon

populations in relation to parasites from farmed salmon. Science 318 (5857): 1772.

Mann BQ 2000. Southern African Marine Linefish Status Reports. Special Publication of the

Oceanographic Research Institute of South Africa. 7: 257pp.

Marine Finfish Farmer’s Association of South Africa (MFFASA) 2010. Marine Fish Farming Environmental

Impact Information.

Melly BL 2011. The Zoogeography of The Cetaceans In Algoa Bay. A thesis submitted in fulfillment of the

requirements for the degree of Master Of Science .Rhodes University. 203pp.

Mead S, Boserrelle C, Black K & D Anderson 2009. Mossel Bay Currents and Fish Farm Dispersal Study.

Specialist report prepared by ASR Ltd for CCA Environmental (Pty Ltd) on behalf of Irvin &

Johnson (Limited).

McChord M, Shipton T and W Sauer 2008. Marine Vertebrate Assessment, Irvin & Johnson’s proposed

aquaculture project, Mossel Bay. Specialist report prepared by Envirofish Africa for CCA

Environmental (Pty Ltd) on behalf of Irvin & Johnson (Limited).

Merceron M., Kempf M., Bentley J.D., Gaffet J., le Grand J. and L. Lamort Datin (2002) Environmental

impact of a salmonid farm on a well fluched marine site: I current and water quality. Journal of

Applied Ichthyology 18: 40-50.

Merella P, Cherchi S, Garippa G, Fioravanti ML, Gustinelli A & F Salati 2009. Outbreak of Sciaenacotyle

panceri (Monogenea) on cage-reared meagre Argyrosomus regius (Osteichthyes) from the

western Mediterranean Sea. Dis Aquat Organ.86(2):169-73.

Moore, A and Waring C (2001) The effects of a synthetic pyrethroid on some aspects of reproduction in

Atlantic salmon. Aquatic Toxicology 52, 1-12

Moran D, Pether SJ, & PS. Lee 2009. Growth, feed conversion and faecal discharge of yellowtail kingfish

(Seriola lalandi) fed three commercial diets. New Zealand Journal of Marine and Freshwater

Research, 43: 917-927

Moses M, Booth M, Allan G & D Boot 2009. Carbohydrate utilisation in Yellowtail kingfish (Seriola

lalandi). Presentation given at the Asia Pacific Aquaculture Conference November 3-6 2009.

Naylor, R., Hindar, K., Fleming, I.A., Goldburg, R., Williams, S., Volpe, J., Whoriskey, S., Eagle, J., Kelso, D.

and Mangel, M., 2005: Fugitive Salmon: Assessing the Risks of Escaped Fish from Net-Pen

Aquaculture. BioScience, Vol. 55, No.5

http://www.ncbi.nlm.nih.gov/pubmed?term=Merella%20P%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed?term=Cherchi%20S%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed?term=Garippa%20G%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed?term=Fioravanti%20ML%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed?term=Gustinelli%20A%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed?term=Salati%20F%5BAuthor%5D&cauthor=true&cauthor_uid=19902846

http://www.ncbi.nlm.nih.gov/pubmed/19902846

55

Navarro, N (2000) Planktonic ecosystem impacts of salmon cage aquaculture in a Scottish sea loch. ICES

Cooperative Research Report 240, Denmark

http://www.biology.au.dk/~biopg/YSCHP/Old/applic/108.HTM

http://www.ices.dk/pubs/crr/crr240/crr240.pdf

Nel, P and D Winter 2008, 2009. Finfish outgrowing in sea cages near the Port Elizabeth Harbour

Environmental Monitoring Programme Reports (1- 4). Prepared for the Department of

Environmental Affairs and Tourism with copies to Irvin and Johnson Pty. Ltd.

Pemberton D and P.D. Shaughnessy (1993) Interaction between seals and fish farms in Tasmania, and

management of the problem. Aquatic Conservation: Marine and Freshwater Ecosystems 3: 149-

158.

Petras, E. 2003. A review of marine mammal deterrents and their possible applications to limit killer

whale (Orcinus orca) predation on stellar sea lions (Eumetopias jubatus). AFSC Processed Report

2003-02, National Marine Fisheries Service, US Department of Commerce. 53p.

Porrello S., Tomassetti P., Manzueto L., Finoia M.G., Persia E., Mercatali I. and P. Stipa (2005) The

influence of marine cages on the sediment chemistry in the Western Mediterranean sea.

Aquaculture 249(1-4): 145-158.

Pittaa P, Apostolakia E.T, Giannoulakia M & I. Karakassis 2005. Mesoscale changes in the water column

in response to fish farming zones in three coastal areas in the Eastern Mediterranean Sea.

Estuarine, Coastal and Shelf Science 65(3): 501–512.

Poortenaar C, Jeffs A, Heath P, & S Hooker 2003. Commercial opportunities for kingfish aquaculture in

Nortland. National Institute Of Water and Atmospheric Research Ltd report compiled for the

Enterprize Northland Trust. Auckland New Zealand

Read, AJ., Drinker, P and S. Northridge. 2006. Bycatch of Marine Mammals in U.S. and Global Fisheries.

Conservation Biology 20: 163–169

Ruiz, J M (2001) Effects of fish farm loadings on seagrass (Posidonia oceanica) distribution, growth and

photosynthesis. Marine Pollution Bulletin 42 (9), 749-760

Schoonbee W & A Bok 2006. Experimental Sea Cage Operational Plan. Irvin and Johnson Pty LTD 29pp.

Staniford D. (2002). Sea cage fish farming: an evaluation of environmental and public health aspects (the

five fundamental flaws of sea cage fish farming). Unpublished paper presented to the European

parliament’s Committee on Fisheries Public hearing on ‘Aquaculture in the European Union:

present situation.

Stickney & J.P. McVey (eds) 2002. Responsible Marine Aquaculture. CABI Publishing, New York.

http://www.biology.au.dk/~biopg/YSCHP/Old/applic/108.HTM

http://www.sciencedirect.com/science/article/pii/S0272771405002234







56

Vita R., Marin A., Madrid J.A., Jimenez-Brinquis B., Cesar A. and L. Marin-Guirao (2004) L. Effects of wild

fishes on waste exportation from a Mediterranean fish farm. Marine Ecology Progress Series

277: 253-261

Wickens P.A. (1995) A review of operational interactions between pinnipeds and fisheries. FAO

Fisheries Technical Paper 346: 86 pp.

Wu 1995 – Wu R.S.S. 1995. The environmental impact of marine fish culture: Towards a sustainable

future, Marine Pollution Bulletin 31: 159-166.

Wuersig, B. (2001) Aquaculture and marine mammals: potential concerns. World Aquaculture Society,

Louisiana State University [Book of Abstracts].

Wuersig, B and GA Gailey 2002. Marine mammals and aquaculture: conflicts and potential resolutions.

In: Stickney & J.P. McVey (eds); Responsible Marine Aquaculture CABI Publishing, New York.

57

7 Appendix 1. Impact Rating Methodology

The significance of all potential impacts that would result from the proposed project is determined in

order to assist decision-makers. The significance rating of impacts is considered by decision-makers, as

shown below.

· INSIGNIFICANT: the potential impact is negligible and will not have an influence on the decision

regarding the proposed activity.

· VERY LOW: the potential impact is very small and should not have any meaningful influence on the

decision regarding the proposed activity.

· LOW: the potential impact may not have any meaningful influence on the decision regarding the

proposed activity.

· MEDIUM: the potential impact should influence the decision regarding the proposed activity.

· HIGH: the potential impact will affect a decision regarding the proposed activity.

· VERY HIGH: The proposed activity should only be approved under special circumstances.

The significance of an impact is defined as a combination of the consequence of the impact occurring

and the probability that the impact will occur. The significance of each identified impact1 was thus

rated according to the methodology set out below:

Step 1 – Determine the consequence rating for the impact by determining the score for each of the

three criteria (A-C) listed below and then adding them. The rationale for assigning a specific rating, and

comments on the degree to which the impact may cause irreplaceable loss of resources and be

irreversible, must be included in the narrative accompanying the impact rating:

Rating Definition of Rating Score

A. Extent – the area over which the impact will be experienced

Local Confined to project or study area or part thereof (e.g. limits of

the concession area)

1

Regional The region (e.g. the whole of Namaqualand coast) 2

(Inter) national Significantly beyond Saldanha Bay and adjacent land areas 3

B. Intensity – the magnitude of the impact in relation to the sensitivity of the receiving environment, taking into

account the degree to which the impact may cause irreplaceable loss of resources

Low Site-specific and wider natural and/or social functions and processes are negligibly

altered

1

Medium Site-specific and wider natural and/or social functions and processes continue albeit in

a modified way

2

High Site-specific and wider natural and/or social functions or processes are severely altered 3

C. Duration – the time frame for which the impact will be experienced and its reversibility

Short-term Up to 2 years 1

Medium-term 2 to 15 years 2

Long-term More than 15 years (state whether impact is irreversible) 3

1 This does not apply to minor impacts which can be logically grouped into a single assessment.

58

The combined score of these three criteria corresponds to a Consequence Rating, as follows:

Combined Score (A+B+C) 3 – 4 5 6 7 8 – 9

Consequence Rating Very low Low Medium High Very high

Example 1:

Extent Intensity Duration Consequence

Regional 2

Medium 2

Long-term 3

High

7

Step 2 – Assess the probability of the impact occurring according to the following definitions:

Probability– the likelihood of the impact occurring

Improbable < 40% chance of occurring

Possible 40% - 70% chance of occurring

Probable > 70% - 90% chance of occurring

Definite > 90% chance of occurring

Example 2:

Extent Intensity Duration Consequence Probability

Regional 2

Medium 2

Long-term 3

High

7

Probable

Step 3 – Determine the overall significance of the impact as a combination of the consequence and

probability ratings, as set out below:

Probability

Improbable Possible Probable Definite

Co

nse

qu

en

ce Very Low INSIGNIFICANT INSIGNIFICANT VERY LOW VERY LOW

Low VERY LOW VERY LOW LOW LOW

Medium LOW LOW MEDIUM MEDIUM

High MEDIUM MEDIUM HIGH HIGH

Very High HIGH HIGH VERY HIGH VERY HIGH

Example 3:

Extent Intensity Duration Consequence Probability Significance

Regional 2

Medium 2

Long-term 3

High

7

Probable

HIGH

Step 4 – Note the status of the impact (i.e. will the effect of the impact be negative or positive?)

Example 4:

59

Extent Intensity Duration Consequence Probability Significance Status

Regional 2

Medium 2

Long-term 3

High

7

Probable

HIGH

– ve

Step 5 – State the level of confidence in the assessment of the impact (high, medium or low).

Depending on the data available, a higher level of confidence may be attached to the assessment of

some impacts than others. For example, if the assessment is based on extrapolated data, this may

reduce the confidence level to low, noting that further groundtruthing is required to improve this.

Example 5:


Regional 2

Medium 2

Long-term 3

High

7

Probable

HIGH

– ve

High

Step 6 – Identify and describe practical mitigation and optimisation measures that can be implemented

effectively to reduce or enhance the significance of the impact. Mitigation and optimisation measures

must be described as either:

Essential: must be implemented and are non negotiable; and

Optional: must be shown to have been considered and sound reasons provided by the

proponent if not implemented.

Essential mitigation and optimisation measures must be inserted into the completed impact assessment

table. The impact should be re-assessed with mitigation, by following Steps 1-5 again to demonstrate

how the extent, intensity, duration and/or probability change after implementation of the proposed

mitigation measures.

Example 6: A completed impact assessment table


Without mitigation

Regional 2

Medium 2

Long-term

3

High

7

Probable

HIGH

– ve

High


xxxxx

xxxxx

With mitigation

Local 1

Low 1

Long-term

3

Low

5 Improbable VERY LOW – ve High

60

Step 7 – Prepare a summary table of all impact significance ratings as follows:

Impact Consequence Probability Significance Status Confidence

Impact 1: XXXX Medium Improbable LOW –ve High

With Mitigation Low Improbable VERY LOW High

Impact 2: XXXX Very Low Definite VERY LOW –ve Medium

With Mitigation:

Not applicable

Indicate whether the proposed development alternatives are environmentally suitable or unsuitable in

terms of the respective impacts assessed by the relevant specialist and the environmentally preferred

alternative.

Documents

FINAL MARINE SPECIALIST REPORT Marine …...cage culture operations (Algoa 1) Essential mitigation measures: Install and maintain suitable predator nets (sufficient strength, visibility