Ecological Baseline Survey of Anguilla’s Five Marine Parksgov.ai/documents/fisheries/Ecological_Baseline_Surveys_of_Anguilla… · Park before the survey work began in earnest

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Ecological Baseline Survey of Anguilla’s Five

Marine Parks

Department of Fisheries and Marine Resources

Note: The conclusions and recommendations of this report are solely the opinions of the author and other contributors and do not

constitute a statement of policy, decision, or position on behalf of the Government of Anguilla. Citation: Wynne S. (2007). Ecological Baseline Survey of Anguilla’s Five Marine Parks. Produced by the Department of Fisheries and Marine Resources for the Anguillian

National Trust as part of an Overseas Territories Environmental Programme funded project. Copies can be obtained by contacting

[email protected]

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Table of Contents

1.0 Introduction 3

2.0 Methods 3

2.1 Choosing Survey Sites 3

2.2 Survey Techniques 4

3.0 Results 6

3.1 Dog Island 6

3.2 Prickly Pear 7

3.3 Sandy Island 8

3.4 Shoal Bay – Island Harbour 9

3.5 Little Bay 10

3.6 Across all Parks 11

4.0 Discussion 14

4.1 Fish Surveys 14

4.2 Habitat Surveys 16

5.0 Conclusions and Recommendations 17

Appendix I – Survey Site Descriptions and Coordinates 19

Appendix II – Notes on Data Analysis and Limitations 24

Appendix III – Example Datasheets 27

References 30

Two supplemental sections are available on request that contain further details than those presented within this report. The first of

these contains mean raw data tables from the survey work conducted, with the second offering tabulated results from a variety of diversity indices for fish species and coral species, with brief comparative analysis and discussion.

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1.0 Introduction

This report represents the contribution made by The Department of Fisheries and Marine

Resources (DFMR) towards phase 1 of the Anguillian National Trusts (ANT) project

‘Enhancing Marine Park Management’ that has been funded by Overseas Territories

Environmental Programme (OTEP). The results from this current aspect of the project,

that being the collection of baseline data for all five of Anguilla’s Marine Parks, will fill a

huge gap in the Departments knowledge base as well as being of vital importance for the

ANT project, and future management of the Marine Parks.

The contents of this report include methodologies used, details of the study sites

surveyed, initial results and short analysis/discussion. There are also comments on project

justification and notes relating to data limitations which are vital to consider if using this

report as the basis of further analysis that will potentially lead to the formulation of

management strategies. These comments are found in the end appendices.

2.0 Methods

The methodology used was chosen to compliment surveyor skill sets while appreciating

man-power and time limitations. Methods were of a relative rapid nature to allow three

surveyors to complete one study site during one dive.

2.1 Choosing Survey Sites

Thirty sites were chosen within the Marine Park boundaries, and distributed to satisfy two

criteria:

• To accommodate the size and variety of use within each Marine Park. I.e. Larger

multiple use Marine Parks have more sites than smaller ones.

• To be representative of the habitats found within the Marine Parks and evenly

distributed among them.

With these criteria in mind, the thirty sites were allocated among the five Marine Parks as

follows:

• Dog Island – 3 Sites

• Prickly Pear – 8 Sites

• Sandy Island – 4 Sites

• Shoal Bay & Island Harbour – 12 Sites

• Little Bay – 3 sites

It should be noted that areas within these Parks, such as sand flats, with very little to

survey within them were avoided, thus effectively stratifying the sampling. This is not to

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say sites were ‘cherry picked’ – a general area to survey was selected using the 1994

Natural Resource Institute (NRI) Atlas, which was subsequently visited for closer

inspection to decide if it was suitable for the purpose of this study. The area was

inspected using a bottom viewer and/or snorkeling equipment, and once a suitable

location was found within this area a GPS point was marked (‘suitable’ meaning

representative habitat within that area). All sites were established this way within each

Park before the survey work began in earnest. All current AMMP PMS (Anguilla Marine

Monitoring Programme Permanent Monitoring Sites – A monitoring scheme run by

DFMR) that are located within the Marine Parks were also used as sites for this project,

thus allowing results to be comparable. I.e. Out-of-park AMMP PMS will potentially be

comparable with the OTEP baseline dataset. Coordinates for all study sites, together with

site descriptions and a map of site locations can be found in appendix I.

2.2 Survey Techniques

Three survey techniques were employed to collect all the required information. As only

three surveyors were qualified to conduct this work (combined with the presence of time

constraints) survey replicates were limited. This is discussed later in the report. However,

all efforts were taken to standardize number of replicates per site within each park, and if

time permitted certain parks were revisited and further survey replicates conducted.

Surveys only took place between 7am and 11am to avoid bias, although in an extreme

circumstance (i.e. Dog Island - perfect weather in this logistically difficult site to reach)

this cut-off was pushed forward to 12 noon to allow work to be fully completed.

Sites were first located using a handheld GPS unit and the previously collected

coordinates. As the site was approached the boat driver indicated the distance remaining

until the site was reached, and upon arrival one of the surveyors drops a small weight into

the water that is attached to a surface marker buoy with rope. This then acted as a point of

reference for both the surveyors and the boat driver, with the marker considered to be

positioned in the center of the study site. From this point, once kitted up, three survey

types were conducted, one by each of the three surveyors present:

Fish Density & Species Diversity – Roving Diver Technique (RDT). One surveyor swam

for 30 minutes at a constant speed of 5m per min, thus allowing data to be quantifiable.

Fish were actively sought and all were recorded in a tally fashion (down to species level)

seen within 2.5 meters either side of the surveyor (thus giving a ‘belt’ of five meters). To

avoid counting the same fish twice swimming direction was random but did not cover the

same area more than once. The survey boundary was again set as no more than 50m from

the central marker and no deeper than 10m. The RDT methodology effectively records

accurately both rare and common species and those that can often be overlooked. Two

replicates were conducted at each site. See appendix III for example datasheet with the

most common species listed prior to survey (other species sighted can be noted by hand).

These data will not only be used for DFMR/ANT purposes but also submitted to REEF

for inclusion in their online database.

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Fish Size Class Distribution – Stationary Point Counts (SPC). A starting position was

randomly selected by the surveyor, and that position held for a minimum of three minutes

to allow fish behavior to return to normal after potential disturbance. Each count took

place over a period of six minutes while the surveyor slowly rotated and tallied fish seen

into family and fish size class (into 5cm size categories). The main emphasis was to

record individuals from families that are known to be either commercially or ecologically

important. Only those individuals within five meters of the surveyor were recorded, thus

allowing data to be quantifiable if so required. Family groups (see datasheet in Appendix

III) were chosen to survey rather than species because it was deemed more realistic for a

single surveyor to achieve, and such a compromise will still yield important information

relating to overall health of fish family populations via size class distribution analysis.

Once each count was completed the surveyor moved to another random location and

began the process again. All counts were carried out in representative habitat no more

than 50 meters from the marker, and no deeper than 10m. Five replicates were conducted

at each site.

Habitat Assessment – Quadrats (0.5m x 0.5m) were randomly distributed around the site

in a stratified fashion so not to include unrepresentative habitat. For example, if a reef

slope was being surveyed, no quadrats were placed on the sand at the bottom of the slope.

No quadrats were placed further than 50m from the marker even if the habitat still

appeared representative, or in water deeper than 10m. Within each quadrat certain criteria

were measured, broken down into three subcategories (physical characteristics,

underlying substrate composition, and percentage cover of biota) as illustrated on the

datasheet in Appendix III. On the whole the survey categories were generic to

compliment surveyor skill sets and time available, although there were spaces for details

to be recorded if necessary. For example in one box the surveyor recorded percentage

cover of sponges within a quadrat and number of individual sponges present. Details

were taken on the type of sponge, split into categories: Vase/barrel, tube, rope, ball and

encrusting. However, the surveyor was encouraged to ID the sponge species (i.e. Red

encrusting sponge rather than just encrusting sponge) and there was space available on

the datasheet for this information to be recorded. The surveyor was also encouraged to go

into more detail by noting percentage covers and numbers of each category of sponge.

The basic philosophy being the more details collected within the time available the better.

Some of the other categories used are explained in the following bullet points:

• Algae/Plants

Turf algae – Including that with sediment amongst it

Fleshy algae – Dictyota sp, Lobophora sp, etc

Calcareous algae – i.e. Halimeda sp, Amphiroa sp, etc

Other macroalgae – i.e. Caulerpa sp, Turbinaria sp, etc

Coralline – Including both crustose coralline algae and reef cement

Seagrass – Thalassis sp, Syringodium sp, etc

Cyanobacteria – Just giving descriptive term, i.e. fuzz ball alga

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• Corals

Hard (Stony) Corals – The reef building Hexacorals. Recorded down to species.

Soft – The Octocorals, split into fans, rods, whips and plumes.

Fire – The Hydrocorals, recorded generically.

Although percentage cover of generic groups were the main variables recorded, some

physical readings were also taken. These were bottom temperature, quadrat depth,

quadrat relief (difference between highest and lowest point) and rugosity (length of 1m

chain when draped over substrate). If possible details were also recorded relating to coral

disease and bleaching, although this largely depended on the surveyor’s ability. A

minimum of 10 quadrats were surveyed per site, with special effort being targeted at

Shoal Bay & Island Harbour Marine Park where a minimum of 15 replicates were set to

increase the robustness of the dataset. This Marine Park is currently of most interest to

the ANT as they have already completed a socioeconomic study of the Park and are

currently working on a proposed management plan for the area.

3.0 Results

Notes on data collected can be found in Appendix II. The full raw dataset is available as a

Microsoft Excel file on the accompanying CD, or by contacting the Department of

Fisheries and Marine Resources (DFMR) or the Anguillian National Trust (ANT).

Alternatively see Supplement 1, available as a separate document, for a detailed

breakdown of mean site characteristics. It should be noted that the common names used

for fish species (and indeed other life forms) are those names proposed by Humann &

Deloach (1989). Photographs of the study sites can also found either on the

accompanying CD, or again by contacting DFMR/ANT. The results presented below are

a summary of these results, split into the five Marine Parks, and the areas within them. A

more detailed statistical analysis of these data would be possible, although this does not

fit into the scope of this project report.

3.1 Dog Island (reef site)

RDT: The most commonly occurring species surveyed within the three Dog Island study

sites were Blue Tang (Acanthurus coeruleus), Bar Jack (Caranx ruber), Caesar Grunt

(Haemulon carbonarium), Bicolor Damselfish (Stegastes partitus), Bluehead Wrasse

(Thalassoma bifasciatum) and Black Durgon (Melichthys niger). The total number of

species recorded were 72 (mean per site 46), with an encounter rate of c.38 fish min-1.

The mean fish density across all sites was 15473 fish ha-1, with the highest densities seen

at site DG02 and DG03 (18493 fish ha-1 and 17040 fish ha

-1 respectively).

SPC: A graph representing the fish family size class distributions for all families

combined across the three Dog Island sites is presented in figure 1a. Triggerfish

(Balistidae), comprising mainly Black Durgon (Melichthys niger), were the largest

individuals recorded, although Surgeonfish (Acanthuridae) were slightly more abundant.

Mean relative abundance across all sites was 123 individuals survey-1, which is again the

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highest for all of the Marine Parks. Of the sites, DG02 again exhibited the highest relative

abundance of fish (197 individuals survey-1), and also housed the largest individuals

across most of the families surveyed, and overall when families combined. The mean fish

family size class recorded across all sites was 20-25cm, with a precise value of 20.7cm.

Habitat: Overall, the underlying substrate of the three Dog Island sites combined was

established as 52.5% solid, 19.8% rubble and 27.7% sand. Physical characteristics

included a mean rugosity value of 67.8, relief of 7.0cm and depth of 7.8m. Percentage

biotic/barren covers across the sites were: 21.2% sand, 28.3% turf algae and/or sediment,

9.7% fleshy algae, 6.3% coralline algae, 2.3% Cyanobacteria, 7.7% hard coral, 8.0% soft

coral, 6.9% fire coral, 8.1% sponge (0.8 individuals m-1) and 2.4% other invertebrates

(1.6 individuals m-1) including, for example, White Encrusting Zoanthids (Palythoa

caribaeorum). Of the sites DG02 was concluded to be the most ‘healthy’, with 4.0%

sand, 37.5% turf algae and/or sediment, 8.5% coralline algae, 3.8% Cyanobacteria, 8.8%

hard coral, 12.5% soft coral, 7.3% fire coral, 13.0% sponge (1.0 individuals per 0.5m2)

and 5.5% other invertebrates (2.1 individuals per 0.5m2). Note: 0% fleshy algae. The

most common species of hard coral seen at this site (and indeed equally across all three

sites) were Mustard Hill (Porites astreoides) and brain corals – mainly Grooved Brain

Coral (Diplora labyrinthiformis). For a definition of ‘health’ in relation to this report

please refer to Appendix II.

3.2 Prickly Pear (reef site)

RDT: The most commonly occurring species surveyed within the eight Prickly Pear study

sites were Blue Tang (Acanthurus coeruleus), Brown Chromis (Chromis multilineata),

Striped Parrotfish (Scarus iserti), and Bluehead Wrasse (Thalassoma bifasciatum). The

total number of species recorded were 94 (mean per site 47), with an encounter rate of

c.30 fish min-1. The mean fish density was 12199 fish ha

-1, with the highest density seen

at sites PP01 and PP07 (17800 fish ha-1 & 15686 fish ha

-1 respectively). The site with the

lowest density was PP04 with 9100 fish ha-1.

SPC: A graph representing the fish family size class distributions for all families combined

across the eight Prickly Pear sites is presented in figure 1b. Parrotfish (Scaridae), had the

largest overall individuals within families recorded, and were also the most abundant.

Mean relative abundance across all sites was 75 individuals survey-1. Of the sites, PP04

exhibited the highest relative abundance of fish (139 individuals survey-1), and also housed

the largest individuals across most of the families surveyed, and overall when families

combined. This particular result is contra to the RDT surveys for Prickly Pear, and is

discussed later. See also Appendix II. The mean fish family size class recorded across all

sites was 15-20cm, with a precise value of 17.0cm.

Habitat: Overall, the underlying substrate of the eight Prickly Pear sites combined was




5.1% fleshy algae, 5.8% calcareous algae, 3.9% coralline algae, 4.5% Cyanobacteria,

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12.8% hard coral, 7.8% soft coral, 4.4% fire coral, 5.3% sponge (0.6 individuals per

0.5m2) and 5.8% other invertebrates (1.1 individuals per 0.5m

2). Of the sites, PP07 was

concluded to be the most ‘healthy’, with 21.5% sand, 11.5% turf algae and/or sediment,

7.8% calcareous algae, 6.7% coralline algae, 7.5% Cyanobacteria, 24.5% hard coral,

10.5% soft coral, 4.5% fire coral, 5.0% sponge (0.6 individuals per 0.5m2) and 1.2%

other invertebrates (0.8 individuals per 0.5m2). Note: 0% fleshy algae. The most common

species of hard coral seen at this site were Finger Coral (Porites porites) and Mustard

Hill (Porites astreoides).

3.3 Sandy Island (reef site)

RDT: The most commonly occurring species surveyed within the four Sandy Island study

sites were Ocean Surgeonfish (Acanthurus bahianus), Bicolor Damselfish (Stegastes

partitus), and Bluehead Wrasse (Thalassoma bifasciatum). The total number of species

recorded were 71 (mean per site 45), with an encounter rate of c.33 fish min-1. The mean

fish density was 13045 fish ha-1, with the highest seen at site SA03 (16060 fish ha

-1). The

site with the lowest density was SA02 with 10140 fish ha-1.


combined across the four Sandy Island sites is presented in figure 1c. Parrotfish

(Scaridae), had the largest individuals overall within recorded families, although

Surgeonfish (Acanthuridae) were the more abundant. Mean relative abundance across all

sites was 53 individuals survey-1 – interestingly the lowest of all Marine Parks. Of the

sites, SA01 exhibited the highest relative abundance of fish (65 individuals survey-1),

although SA04 housed the largest individuals across most of the families surveyed, and

overall when families combined. The mean fish family size class recorded across all sites

was 10-15cm, with a precise value of 13.6cm.

Habitat: Overall, the underlying substrate of the four Sandy Island sites combined was




9.8% fleshy algae, 0.2% calcareous algae, 4.9% coralline algae, 0.4% Cyanobacteria,

11.0% hard coral, 15.8% soft coral, 5.1% fire coral, 9.8% sponge (1.0 individuals per

0.5m2) and 1.0% other invertebrates (0.4 individuals per 0.5m

2). Of the sites, SA01 was

concluded to be the most ‘healthy’, with 24.0 sand, 20.5% turf algae and/or sediment,

6.0% fleshy algae 3.0% coralline algae, 12.0% hard coral, 15.0% soft coral, 4.0% fire

coral, 13.5% sponge (0.9 individuals per 0.5m2) and 1.5% other invertebrates (0.3

individuals per 0.5m2). The most common species of hard coral seen at this site was

Mustard Hill (Porites astreoides). It should be noted however that site SA03 exhibited

better values for some variables than SA01, but overall the dataset suggested it to be

more ‘healthy’. For a definition of this term see Appendix II.

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3.4 Shoal Bay - Island Harbour (reef site)

RDT: The most commonly occurring species surveyed within the twelve Shoal Bay and

Island Harbour study sites were Blue Tang (Acanthurus coeruleus), Ocean Surgeonfish

(Acanthurus bahianus) and Bluehead Wrasse (Thalassoma bifasciatum). The total

number of species recorded were 100 (mean per site 51), with overall densities at many

of the sites lower than in the other reef dominated Marine Parks, with (SB07 being the

lowest at 6800 fish ha-1). The highest density was recorded at SB05 with 15213 fish ha

-1,

followed by SB02 with 14400 fish ha-1, SB06 with 14300 fish ha

-1 and SB03 with 13980

fish ha-1. Mean overall encounter rate across all sites was c.27 fish min

-1.


combined across the twelve Shoal Bay - Island Harbour sites is presented in figure 1d.

Parrotfish (Scaridae), had the largest overall individuals within families recorded,

although Surgeonfish (Acanthuridae) were the more abundant. Mean relative abundance

across all sites was 88 individuals survey-1. Of the sites, SB02 exhibited the highest

relative abundance of fish (142 individuals survey-1), although SB08 housed the largest

individuals across most of the families surveyed, and overall if all families combined

(although larger parrotfish were seen at SB10). On the whole, fish were markedly smaller

compared to other reef dominated Parks with, for example, Parrotfish (Scaridae) not

exceeding 30cm in size at over half the study sites, and not exceeding 20cm at a quarter

of them. Even those sites with larger parrotfish had very low densities present. The mean

fish family size class recorded across all sites was 10-15cm, with a precise value of

11.9cm.

Habitat: Overall, the underlying substrate of the twelve Shoal Bay - Island Harbour sites

combined was established as 60.6% solid, 28.5% rubble and 10.9% sand. Physical

characteristics included a mean rugosity value of 49.0, relief of 14.0cm and depth of

7.0m. Percentage biotic/barren covers across the sites were: 13.9% sand, 30.2% turf algae

and/or sediment, 17.7% fleshy algae, 7.9% calcareous algae, 6.0% coralline algae, 0.2%

other algae, 3.7% Cyanobacteria, 6.6% hard coral, 5.4% soft coral, 2.2% fire coral, 4.7%

sponge (0.7 individuals per 0.5m2) and 1.4% other invertebrates (0.5 individuals per

0.5m2). Of the sites, SB02 was concluded to be the most ‘healthy’, with 16.4 sand, 9.9%

turf algae and/or sediment, 17.7% fleshy algae, 9.1% calcareous algae, 10.3% coralline

algae, 3.1% Cyanobacteria, 13.7% hard coral, 9.6% soft coral, 2.4% fire coral, 2.8%


0.5m2), mainly White Encrusting Zoanthids (Palythoa caribaeorum). There was a good

variety of hard coral at this site with the most common species judged to be Mustard Hill

(Porites astreoides). Again, as with Sandy Island, it should be noted that other sites

exhibited ‘healthier’ values for some variables (i.e. lower fleshy algae cover) than SB02,

but on the whole the dataset suggested this site to be more ‘healthy’.

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Size Class (cm)

50+45-5040-4535-4030-3525-3020-2515-2010-155-100-5

Frequency (mean per survey)

30

20

10

0

Size Class (cm)

50+45-5040-4535-4030-3525-3020-2515-2010-155-100-5


20

10

0

Size Class (cm)

50+45-5040-4535-4030-3525-3020-2515-2010-155-100-5


20

10

0

Size Class (cm)

50+45-5040-4535-4030-3525-3020-2515-2010-155-100-5


30

20

10

0

Figure 1 (a-d): Mean frequencies of fish size class for the four reef dominated sites, Dog

Island (1a), Prickly Pear (1b), Sandy Island (1c) and Shoal Bay-Island Harbour (1d).

3.5 Little Bay (seagrass site)

RDT: The most commonly occurring species surveyed within the three sites at Little Bay

was Slippery Dick (Halichoeres bivittatus). Also recorded in high numbers (over 250 fish

ha-1) were juvenile Grunts (Haemulon sp.), juvenile Yellowtail Snapper (Ocyurus

chrysurus), juvenile Redband Parrotfish (Sparisoma aurofrenatum) and Blackear Wrasse

(Halichoeres poeyi). The total number of species recorded were 35 (mean per site 21),

with an encounter rate of c.10 fish min-1. The mean density of fish across all sites was

4173 fish ha-1.

1a 1b

1c 1d

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SPC: All fish recorded in Little Bay were smaller than 10cm (note: Wrasse were not

counted using this method, and some Slippery Dick were seen larger than this), and

juveniles (again with the exception of Wrasse that were not surveyed). The relative

abundance across the sites was 13 individuals survey-1. Of interest, although not seen

during a survey, was a juvenile Nassau Grouper (see plates at end of section).

Habitat: Overall, the underlying substrate of the three Little Bay sites combined was

established as 0.2% rubble and 99.8% sand, with a depth of 8.9m. Percentage


0.5% fleshy algae, 13.5% calcareous algae, 1.0% other algae, 61.1% turtle grass, 0.7%

Cyanobacteria, 0.1% hard coral, 0.7% sponge (0.3 individuals per 0.5m2) and 0.6% other

invertebrates (0.1 individuals per 0.5m2). The only hard coral noted was Rose Coral

(Manicina areolata). Only one Queen Conch (Strombus gigas) was recorded which was a

juvenile, thus giving a density of 0.1 individuals per m2.

3.6 Across all Parks

As Little Bay Marine Park was the only seagrass area surveyed it will be left out from

this section and comparisons only made between the four coral reef regions.

RDT: The most commonly occurring species surveyed were Bluehead Wrasse

(Thalassoma bifasciatum), see plates at end of section. Other ranking species were Blue

Tang (Acanthurus coeruleus), Ocean Surgeonfish (Acanthurus bahianus) and Bicolor

Damselfish (Stegastes partitus). Also occurring in high numbers (over 500 individuals

ha-1) were Bar Jack (Caranx rubber), Brown Chromis (Chromis multilineata), and

Striped Parrotfish (Scarus iserti). Other high densities (between 250 and 500 individuals

ha-1) were recorded for French Grunt (Haemulon flavolineatum), Caesar Grunt

(Haemulon carbonarium), Longfin Damselfish (Stegastes diencaeus), Blue Chromis

(Chromis cyanea), Stoplight Parrotfish (Sparisoma viride), Princess Parrotfish (Scarus

taeniopterus), Redband Parrotfish (Sparisoma aurofrenatum), Slippery Dick

(Halichoeres bivittatus) and Black Durgon (Melichthys niger). The total number of

species recorded were 122, with an encounter rate of c.33 fish min-1. The density of fish

across all sites was 12870 fish ha-1. Grouper densities were low throughout all sites, with

the most common being the Coney (Cephalopholis fulvus) that had a density of 38

individuals ha-1. All other grouper species had a density of less than seven individuals

ha-1, with no Nassau Groupers (Epinephelus striatus) being recorded at all.

The five sites with densest fish populations were: DG02 (18493 fish ha-1), PP01 (17800

fish ha-1), DG03 17040 fish ha

-1, SA03 (16060 fish ha

-1) and PP07 (15686 fish ha

-1). The

five lowest sites were: SB07 (6800 fish ha-1), SB04 (7793 fish ha

-1), SB11 (7986 fish

ha-1), SB12 (8806 fish ha

-1) and PP04 (9100 fish ha

-1). It is interesting to note that four of

the five lowest density sites, and none of the five highest density sites, were found in

Shoal Bay - Island Harbour Marine Park. Across the parks as whole Dog Island exhibited

the highest densities of fish, followed by Sandy Island, Prickly Pear and finally Shoal

Bay - Island Harbour.

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SPC: Table 1 details the fish family size class distributions for all families combined

across all reef dominated Marine Parks, mean totals of which are represented in figure 2.

Table 1: Fish family size class distributions for all families combined across all Marine Parks.

The values represent mean number seen per 6 minute survey. Average survey depth was 5.95

meters. See figure 6 for graphical representation.

Size Class (cm) <5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 >50 Totals

Angelfishes 0.04 0.12 0.17 0.09 0.13 0.08 0.01 0 0 0 0 0.63

Butterflyfishes 0.18 0.35 0.41 0.12 0 0 0 0 0 0 0 1.05

Surgeonfishes 3.35 4.46 6.97 8.67 4.40 0.88 0 0 0 0 0 28.73

Jacks 0.04 0.91 1.11 2.10 1.15 0.25 0.13 0 0.01 0 0.01 5.72

Grunts 0.31 0.31 0.34 1.92 2.51 2.09 0.44 0.06 0 0 0 7.99

Snappers 0.01 0.09 0.10 0.28 0.97 1.08 0.04 0.03 0 0.02 0 2.60

Damselfishes 4.04 4.57 3.27 1.60 0 0 0 0 0 0 0 13.47

Groupers 0 0.01 0.02 0.12 0.24 0.16 0.15 0.13 0.06 0.03 0 0.91

Parrotfishes 1.79 2.37 4.01 2.22 2.04 1.25 0.89 0.71 0.65 0.38 0.02 16.32

Triggerfishes 0.02 0 0 0.97 1.40 1.38 2.06 1.21 0.03 0.04 0 7.11

Barracuda 0 0 0 0 0 0 0 0 0 0 0.07 0.07

Hogfishes 0 0.02 0 0 0 0 0 0.01 0 0 0 0.03

Goatfishes 0 0.09 0 0 0 0 0 0 0 0 0 0.09

Moray Eels 0 0 0 0 0 0 0.01 0.01 0.01 0 0.02 0.05

Totals 9.78 13.30 16.38 18.10 12.83 7.16 3.73 2.17 0.77 0.45 0.11 84.79

Size Class (cm)

50+45-5040-4535-4030-3525-3020-2515-2010-155-100-5


20

10

0

Parrotfish (Scaridae), had the largest overall individuals within families recorded,

although Surgeonfish (Acanthuridae) were the more abundant. Mean relative abundance

across all sites was 85 individuals survey-1. The site with largest Parrotfish was PP04.

Dog Island had the overall mean largest fish of commercial and/or ecological importance

(20.7cm) and Shoal Bay - Island Harbour the smallest (11.9cm). Two important families

of interest that should be mentioned are Groupers and Jacks. Of all grouper species the

Coney was the most abundant, with an overall density across coral reef dominated sites

of c.38 individuals ha-1. All other species had a density of less than 7 individuals ha

-1,

Figure 2: Mean frequency of fish size

class across the four reef dominated

sites combined.

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which is very low indeed. Jacks also didn’t rank as highly as would have been expected,

with most sites having no individuals recorded larger than 20cm. Their mean size across

all sites was 16.7cm, although a couple larger individuals were recorded at a small

number of sites.

Habitat: Overall, the underlying substrate of the twenty seven reef sites combined was



biotic/barren covers across the sites were: 21.5.9% sand, 23.6% turf algae and/or

sediment, 10.6% fleshy algae, 3.5% calcareous algae, 5.3% coralline algae, 0.1% other

algae, 2.7% Cyanobacteria, 9.5% hard coral, 9.2% soft coral, 4.7% fire coral, 7.0%


0.5m2). Of the sites, PP07 was concluded to be the most ‘healthy’, with characteristics as

described previously. The most common species of coral was judged to be Mustard Hill

(Porites astreoides), followed by finger coral (porites porites) – see following plates.

Color Plates: Clockwise from top left: Juvenile Nassau grouper seen in Little Bay; Mustard Hill, the most

commonly occurring coral species; Bluehead Wrasse, the most commonly occurring fish species; and a

large Finger Coral colony, probably the second most common coral species, photographed at site SA03.

14

4.0 Discussion

4.1 Fish Surveys – both RDT and SPC survey types

Results show that there is a tendency for densest populations of fish, with the largest

individuals, to be found around the off-shore cays, especially those areas that are more

logistically difficult to visit (i.e. more inaccessible & exposed). For example PP04, which

is found on the north coast of Seal Island (part of the Prickly Pear Marine Park), housed

the largest individual parrotfish. According to SPC results it also had the highest relative

abundance of commercially and/or ecologically important species (This result is contra to

that found when conducting RDT surveys, although this could be an artifact of the

sampling method and is discussed both later and in Appendix II). This result is especially

interesting when relating it to habitat results, as PP04 has the least rugose reef structure of

all Prickly Pear site surveyed, the second highest fleshy algae cover and the second

lowest live hard coral cover. This essentially sets it among the least ‘healthy’ Prickly Pear

sites, a fact that inaccessibility of the area likely mitigates when considering site

favorability for a dense fish population(within reason). By this it is meant that there

seems a possibility of inaccessibility leading to lower fishing pressure, and therefore ‘safe

houses’ for fish populations.

Further examples of inaccessibility possibly influencing fish SPC results (i.e. primarily

size class distribution) can be highlighted when looking at mean size of individuals

surveyed. Dog Island, the most distant site (with visitation largely weather depending and

inaccessible for many weeks of the year), had the largest mean fish size of 20.7cm (size

class 20-25cm), with Prickly Pear (some sites accessible, others more inaccessible)

having the second largest figure of 17.2cm (size class 15-20cm). Sandy Island, which is

easily accessible but a short distance off-shore, had a mean fish size of 13.7cm (size class

10-15cm), whereas Shoal Bay - Island Harbour, the most accessible Marine Park (it is

mainland coastal) had the smallest mean fish size of 11.9cm. This does admittedly put it

in the same size class category as Sandy Island, although when looking at the habitat

data, Shoal Bay - Island Harbour would appear to have a more complex (higher rugosity

and relief values) and therefore potentially better fish habitat. It is known from previous

studies (Wynne & Côté 2007) that higher quality habitat can mitigate impacts from

fishing, and it is known that fishing in Shoal Bay - Island Harbour is indeed intense.

Sandy Island reportedly has moderately high fishing activity, although the number of

traps observed (pers. obs.), and poorer accessibility for spear fishers (with Shoal Bay -

Island Harbour being ideal for this), mean this intensity is likely much lower. This being

the case, Sandy Island has possibly suffered more from a lower intensity of fishing than

Shoal Bay - Island Harbour would have, although because in this latter Park fishing

intensity is thought to be that much higher habitat mitigation has lead to both Parks being

in a somewhat similar state in terms of mean fish size class. This is further backed up by

the relatively low complexity of the study sites around Dog Island, and those having the

largest, mean fish size of all the Marine Parks.

15

Similar results were yielded from RDT surveys, where the densest populations of fish

were found around Dog Island and the least dense in Shoal Bay - Island Harbour Marine

Park. When considering the other two Park areas results vary, with Sandy Island having

the largest mean value, although Prickly Pear has the highest value of any particular site

across both regions. Because RDT fish density results include those species not targeted

by fishers and that are often too small to even be caught as by-catch these results do not

necessarily relate to the same issues as previously speculated, but paint a rather more

complex picture of other factors that can effect fish distribution. Deciphering these

factors would require a more in-depth analysis than is presented here. It does however

compliment the SPC size class results and suggest that Dog Island is the ‘healthiest’

region from a fish point of view over the other three coral reef dominated Marine Parks,

and special attention should be given to it when considering management options in order

to conserve it as such. Having said this, Shoal Bay - Island Harbour with the smallest

individuals and least dense populations across all of the coral reef dominated Marine

Parks doesn’t represent a ‘lost cause’ and again should be given special attention in order

to manage it in such a way as to not let it degrade any further. After all, with the highest

number of species counted (all other parks had a very similar number of species recorded,

suggesting Shoal Bay – Island Harbour is special from a diversity point of view),

combined with the highest mean number of species recorded at each site and a relatively

healthy population of juveniles (i.e. smaller individuals), there is plenty of scope for

action, but it is urged sooner rather than later. It is an interesting fact that this Park has the

highest recorded species diversity, a strong case for urgent attention to be paid to in from

a conservation point of view. It should be noted that relative densities of commercially

and/or ecologically important species from SPC surveys ranked Shoal Bay - Island

Harbour second under Dog Island (although individuals were indeed markedly smaller),

contra to RDT results. A more detailed analysis, possibly breaking down the RDT results

into family groups as with SPC surveys, may yield different results than discussed above

and explain such contra results. Alternatively, specific families may be looked at (see

below), again removing inconsistencies that might be present when grouping all fish

families together. This will likely be an area investigated on a deeper level during

subsequent and more detailed analysis.

Results suggest that grouper populations are much reduced from that supposed

historically. Nassau grouper for example, are known to have been abundant a few

decades ago, although during this project no individuals were recorded. It is known on a

regional level that they have been over-exploited due to harvesting their spawning

aggregations in an extremely efficient manner. One juvenile was sighted in Little Bay,

although not during a survey, and also sub-adults have been sighted during other work

conducted by DFMR, although admittedly not on a regular basis. Their populations are at

such a low level that they have become an exciting sight, almost making a dive special,

rather than a commonly sighted species of great commercial interest. They can currently

be classed as commercially extinct in Anguilla and it is suggested that protective

management be employed in the near future to try and encourage their re-establishment.

Having said this, groupers are generally quite reclusive and often cryptic in nature (the

Coney might be seen as being the least so, possible explaining it’s higher recorded

density), so this may partially explain results. However, the extreme paucity of Nassau

16

grouper suggests that even though a cryptic nature may reduce observability, it would not

explain the results of this study and so represents a marked reduction in density of a

previously abundant species. This can therefore possibly be extrapolated to all grouper

species, although lacking historical information firm conclusions can’t be draw. It should

be noted that Dog Island once again had the highest number of individuals recorded.

4.2 Habitat Surveys

Results from the habitat surveys suggests that a variety of health states exist throughout

the Marine Parks, from high/moderate to bad. It is difficult to conclude the overall health

of all Parks combined because of the extremely complex set of ecological interactions

that occur within a coral reef ecosystem, however what is clear is that the mean live hard

coral cover is rather low at 9.5%. Fleshy algae cover varies from 0% to almost 35%,

which highlights the variation within habitats present in Anguillian coral reef dominated

areas. If one site were to be chosen as the most ‘healthy’ it would have to be PP07, which

was recorded to have the highest live coral cover of all sites at 24.5% and 0% fleshy

algae. Fish density here was also within the top five sites, although it should be noted that

SPC results didn’t reflect this.

The seagrass areas surveyed in Little Bay are concluded to be in good health, although

there was a reduction in percentage of seagrass noted when compared to the Oxenford &

Hunte study of 1990, where the present cover of 61.1% shows a marked reduction from

their recorded value of 82.3%. The map of Little Bay produced by Oxenford & Hunte

suggests that the size of seagrass beds have much reduced over the last 17 years. There

are also some changes in fish composition, for example, the presence of Yellowtail

Parrotfish (Sparisoma rubripinne). However, precise data are hard to extract and the

exact locations of the study sites not entirely clear, making robust comparisons difficult

to make: Yellowtail Parrotfish are known to exist around the more rocky regions on the

periphery of the seagrass bed here.

The Dog Island site DG02 was in an almost identical location to one of the sites studied

by Oxenford & Hunte in 1990. Although it is recognized that even a difference of a few

hundred meters can make all the difference when making such comparisons, it does offer

the chance to do so, and combined with Little Bay represents one of the only two such

historical comparisons that can be made. Hard coral cover has dropped from 23% in 1990

to 9% in 2007, although percentage covers of sponges and algae have remained almost

the same. Few details are given relative to fish species present in the 1990 survey

although the site did have the highest number present among all similar sites surveyed.

On the whole (in general terms), the sites at Shoal Bay – Island Harbour exhibited the

poorest state of health with high fleshy algae and low live coral cover, also with high

levels of sediment cover (albeit this category is combined with turf algae which can be

seen as a beneficial characteristic – see Appendix II). The situation is especially

concerning within the Shoal Bay – Island Harbour Marine Park because it has the highest

complexity values (mean rugosity 49.0, mean relief 14.0) of all the others. This suggests

it used to be an area of high live coral cover, hence the present complexity of the existing

17

(mainly dead) reef areas. If this area is to afford us the coastal protection its reefs have

given Anguilla in the past it is of vital importance that this ‘phase shift’ towards an algae

dominated reef be addressed if at all possible. The factors that cause such a ‘shift’ are

again extremely complex and on the whole poorly understood. Indeed this topic is of

much debate within the scientific community. Generally however it is attributed to a

variety of reasons including (but not limited to): Over-fishing removing grazers and

traps/anchoring damaging the living reef; Diadema autillarum reductions since it’s

1980’s mass mortality event; sea temperature rises increasing mortality from bleaching

events; nutrients input making our coastal waters eutrophic; ocean acidification

interfering with coral physiology; and natural disturbance events increasing in frequency

and severity. Shoal Bay – Island Harbour, being a major tourist hot-spot with many

developments present/under construction (not to mention untold future expansion),

finding a possible solution to at least some of these issues is of utmost significance.

However, it does pose the typical problem of doing so without negatively affecting this

economically important industry. DFMR have begun doing whatever possible to address

these issues with: Diadema antillarum being translocated into the Park from other areas

threatened by destructive coastal development; Establishment of long-term monitoring

sites; the maintenance of mooring buoys to discourage anchoring; reviews of fishery

legislation; and a comprehensive water quality monitoring programme soon to be set up

in collaboration with the water lab. Obviously many of the negative impacts to our ocean

realm have to be dealt with on a regional, if not global, level so are largely out of our

control. However, if those areas that can be addressed locally are to be done so

effectively, it needs the full backing of and support from the Government of Anguilla.

5.0 Conclusions and Recommendations

The sites at Dog Island within this study did not exhibit exceptionally ‘healthy’ habitat

characteristics and so the question is raised as to why it houses such a dense fish

population? It is concluded that these more exposed sites exhibit such characteristics

because they are less likely to be affected by land based ‘pollution’, and are regularly

flushed through (bringing in plenty of food) by strong currents. Similar conclusions can

be drawn when looking at specific sites in detail, as with PP01 which has the second

highest fish density and also relatively ‘healthy’ habitat (although again, like Dog Island,

it does not have high complexity values which are normally associated with higher fish

densities). This site is once more very exposed, being located on the western end of

Prickly Pear West, so currents will regularly flush the area and bring in plenty of food for

primary consumers at the bottom of the food chain and other plankton eaters. These

examples show how reef complexity is not the only, nor the vital, component that

influences fish density, and how important it is to consider each site separately when

drawing in-depth conclusions that will be the building blocks for future management

plans.

The main overall conclusion to be drawn is that in general the healthier habitats are found

further away from mainland Anguilla and the apex of these in the most inaccessible

areas. This fact in itself has management implications, but also presents decisions that fist

18

have to be made: When considering conservational management options should priority

be given to the healthiest sites, and say, make them permanently (or at least seasonally)

closed areas? Or should this happen to the most degraded site in an effort to restore them,

or at least aid their restoration? These questions of course come solely from a fisheries

management perspective, but similar situations present themselves when considering

other (albeit only anthropogenic) causes. For example, Shoal Bay – Island Harbour has

the heaviest tourist usage out of all five Marine Parks (pers. obs.) and Dog Island the

least. Should this be more strictly controlled and potentially effect one of Anguilla’s most

important industries? Another example is highlighted by speculating that nutrient levels

are higher in Shoal Bay – Island Harbour due to land based leaching and/or lower level of

water movement effectively flushing the area on a regular basis. This is an area that

should be looked at in great detail and is indeed part of DFMR’s future work plan.

Below are some recommendations that can be made from the information presented

within this report:

• Special attention should be given to those Marine Parks that are closest to

mainland Anguilla, and the management of these areas enhanced.

• An investigation should be made as to whether Dog Island, especially that area

around West Cay, be nominated for special status as an almost pristine region.

• Special management should be considered for fish species that are recorded in

lower numbers than historically suggested, for example groupers and jacks.

• With a full coastal water quality monitoring programme soon to begin, legislative

support should be given to back up any recommendations made from it. Other

initiatives carried out by DFMR, such as the recent Diadema antillarum

translocations should also be encouraged and supported.

• Independent monitoring schemes by developers should be encouraged, as well as

exploring the potential to establish an educational field station that would

facilitate visiting students or researchers to conduct their work in Anguilla.

Endeavors such as these will help build the knowledge base that is currently

lacking which is essential in assisting with in the decision making process that is

needed when pursuing sustainable development.

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Appendix I – Survey Site Descriptions & Coordinates

Shoal Bay – Island Harbour Marine Park

SB01 (N18 15.584 W063 02.549) – Pavement reef with scattered dead coral heads. Lots of soft corals and reasonable fish presence. Classed as mixed reef community, low complexity. Shot placed on flat area

close to small sand channel.

SB02 (N18 15.167 W063 02.469) – Same area as AMMP site. Complex dead Acropora palmata stands

in shallow parts (also a couple of live ones), more mixed community on slope into deeper region. Sand

bottom at 18m. Algae dominated on the most part. Classed as mixed reef community, high complexity.

Shot placed in the middle of a partially dead large Montastraea annularis colony.

SB03 (N18 15.723 W063 02.026) – Shallow area with dead Acropora palmata and Proites porites colonies. In very shallow area it is mostly very bare flattened coral rubble. As site deepens it become more

scattered coral heads with Porites porites fragments scattered around sandy areas. Soft corals also. Classed

as mixed reef community, medium complexity. Shot placed amongst dead Acropora palmata stands, close

to large dead Porites porites structures.

SB04 (N18 15.425 W063 02.110) – Situated near Shoal Bay Reef dive buoy. Quite similar in many ways to SB02 although less Acropora palmata rubble/dead stands and more algae cover. Shallow but slopes

down to sandy bottom around 18m. Some fish diversity but abundance seems low. Classed as algae

dominated mixed reef community, high complexity. Shot placed in approximately 5m of water among

rubble and soft corals.

SB05 (N18 15.854 W063 01.499) – Situated near Lobster Reef dive buoy. Small slope from shallows into deeper water made up of rubble from various coral species. Resembles a grave yard somewhat with

low live hard coral cover. Some soft corals. Fish diversity & abundance seemed low. Classed as mixed reef

community, medium complexity. Shot placed in small sand/rubble patch surrounded by soft corals.

SB06 (N18 15.572 W063 01.604) – Same area as AMMP sub-site (to become site in it’s own right when

more are added to the AMMP project). Reef slopes from shallows (mainly consisting of Porites porites &

Montastraea annularis colonies – both alive and dead) down to 19m sandy bottom. Many fish swimming

(Snappers, Sergeant Majors, Parrotfishes, Grunts, Chromis) off slope over deeper water. Down slope coral

diversity increases (both hard & soft) although much is dead and algae predominates. Classed as algae

dominated mixed reef community, medium – high complexity. Shot placed in 5m of water on Porites

porites rubble.

SB07 (N18 15.752 W063 01.314) – Similar in many ways to SB06, although here in shallows many dead Acropora palmata stands predominate, and slope down to sandy bottom is only 12m. Very low fish

diversity and high algae cover. Many soft corals and intrusive fish/crayfish traps. Classed as algae

dominated mixed reef community, medium – high complexity. Shot placed in small sand patch surrounded

by dead coral heads.

SB08 (N18 15.497 W063 01.034) – Located inshore between Shoal Bay East (Upper) and Island Harbour. Large patch reefs, with this site being located on the northern edge of one. Shallow reef (3m with

some structures breaching surface) that gradually slopes down to sandy bottom at 12m in parts, although

sandy areas are shallower in parts. Algae dominated with not much live hard coral. Soft corals quite

abundant. Fish diversity and abundance reasonable with large parrotfish common. Classed as Algae

dominated mixed reef community, medium to high complexity. Shot placed on flat area near large

Montastraea annularis colony.

20

SB09 (N18 16.017 W063 00.110) – Inner side of outer reef area north of Scilly Cay. Generally flat with small – medium old coral heads of mixed species. Small sand patches. Lots of small soft corals suggesting

past mortality event. Fish abundance high if considering smaller species, although a few parrotfish were

present. Similar in many ways to SB01. Algae present in quantity but not as dominant as at other sites.

Classed as mixed reef community, low complexity. Shot placed in bare area close to one of the larger small

sand patches.

SB10 (N18 15.798 W063 00.224) – Outer side of inner reef slightly west of Scilly Cay. Steep reef slope (made mainly from dead and broken Acropora palmata stands – in shallows some still survives) from 2m

shallows drops to sandy bottom at 9m. Sandy bottom has scattering of coral structures/rock. Heavy algae

growth and little live hard coral apparent. Quite an abundance of reasonable sized Parrotfish. Good variety

of soft corals. Classed as algae dominated mixed reef community of high complexity. Shot placed in

around 5m of water on slope (about 100m east of submerged pedal boat).

SB11 (N18 15.898 W062 59.873) – Outer side of inner reed slightly east of Scilly Cay. Shallow area (2-5m) of pavement reef with some raised topology. Large numbers of soft corals, but also small hard coral

colonies present. Some small dead Acropora palmata stands, although a few patches are still alive. Fire

coral appeared common. Lots of small juvenile fish noted, with a scattering of large parrotfish too. Algae

not dominant. Classed as a mixed reef community of low complexity. Shot placed close to raised topology,

with flatter region to the north.

SB12 (N18 15.828 W062 59.723) - Located on end of reef that stretches past back of Scilly Cay. Complex Acropora palmata stands/rubble. Shallow in parts but slopes down to c.8m deep sand/rubble

region. Algae dominated reef with low live hard coral cover and limited soft corals. Fish diversity and

abundance low although a few large Parrotfish were noted. This area seems somewhat ecologically dead

although it is classed as algae dominated mixed reef community, high complexity. Shot placed on coral

rubble at c4m.

Little Bay Marine Park

LB01 (N18 13.641 W063 04.216) - Located around AMMP site in eastern side of Marine Park. Sea

grass, with mixed Halimeda and saucer blade algae. All fish sighted were small/juveniles. Approximately

6m in depth. Numerous small sand hills and a couple of bare sand patches present. Classed as seagrass bed.

Shot placed in small sand patch.

LB02 (N18 13.572 W063 04.379) - Located around AMMP site in central part of Marine Park. Sea grass,

with mixed Halimeda and saucer blade algae. All fish sighted were small/juveniles. Approximately 8.5m in

depth. Numerous small sand hills present. Site situated closer to some larger sandy areas than other sites at

Little Bay. Classed as seagrass bed. Shot placed in small sand patch.

LB03 (N18 13.452 W063 04.340) - Located in western side of Marine Park. Sea grass, with mixed

Halimeda and saucer blade algae. All fish sighted were small/juveniles. Approximately 8m in depth.

Numerous small sand hill and some bare sand patches present, some larger than others. Classed as seagrass

bed. Shot placed in small sand patch.

Sandy Island Marine Park

SA01 (N18 12.773 W063 07.588) – Located close to the small cay NW of Sandy Island. 4 – 7 meters in

depth with sandy/rubble bottom dominated by soft corals (some hard corals present – mainly Mustard Hill

although noticed a bit of Staghorn). Mainly juvenile fish (lots of small blue headed wrasse), surgeonfish

and parrotfish. Classed as soft coral dominated mixed reef community of low complexity. Shot placed in

sand patch near slightly raised area with dead coral heads and lots of soft corals (mainly Sea Plumes)

housing a huge shoal of French Grunts.

21

SA02 (N18 12.549 W063 07.481) – Located southwest of Sandy Island. This site is very similar to SA01 although some patches of soft corals seemed rather denser here. Fish assemblage seemed similar also

although no large schools of French Grunts noted. Classed as soft coral dominated mixed reef community

of low complexity. Shot placed in sand patch near dense soft coral area (mainly Sea Plumes).

SA03 (N18 12.841 W063 07.148) – Located on eastern side of reef around sandy island quite close to ship wreck. Highest amount of hard coral seen to date with huge finger coral colonies and good sized

Montastraea sp. Also Staghorn colonies present which are rare around Anguilla. Some sandier areas and

also some areas that appear fairly barren/dead. Some algae but patchy. Hundreds of Chromis noted. Classed

as hard coral dominated mixed reef community of medium complexity. Shot placed in sand/silt depression

in middle of a huge finger coral colony.

SA04 (N18 12.850 W063 06.934) – Located east of site SA03. Sand channels with ridges of hard corals (dead Acropora palmata etc). Gradual slope into a sandy bottom at around 10m. Reasonably abundant soft

corals, with live hard coral being quite sparse. Moderate fish abundance and diversity. Class as mixed reef

community of medium complexity. Shot placed in one of the sand channels.

Prickly Pear Marine Park

PP01 (N18 15.995 W063 11.403) – Located on southwestern side of Prickly Pear West, comprising a

small ridge with interspersed sand holes. Not much hard coral cover but many brightly coloured sponges

and also lots of small soft corals. Good fish diversity with both small juveniles and larger individuals

(Barracuda, French Grunts etc). Hundreds of Bluehead wrasse. Also sighted a Hawksbill Turtle. Depth

between 5 – 10 meters (although more shallow areas present near sea rocks). Not algae dominated. Classed

as mixed reef community of low complexity. Shot placed on flat area on top of the ridge.

PP02 (N18 16.290 W063 10.567) – Located on northern side of Prickly Pear East in inner area of outer reef. Many large coral heads with small sand patches or lower relief hard bottom. Large Montastraea

annularis colonies present in mixed states of health – some mostly dead. Also areas of Acropora palmata

rubble – a few colonies alive. Limited soft corals present. Fish diversity and abundance moderate. Some

algae growth, but hard to say if it is dominant. Classed as mixed reef community of medium/high

complexity. Shot placed in small sand patch surrounded by (mainly dead) coral colonies.

PP03 (N18 15.718 W063 10.070) – Located on eastern end of Prickly Pear East. Shallow region near rocks comprised of sandy bottom with quite dense scattering of coral colonies/heads. Good diversity of fish

present with both juveniles and adults (especially Parrotfish). Depth 3 – 7 meters. Not algae dominated.

Classed mixed reef community of medium complexity. Shot placed on sand patch amongst coral heads.

PP04 (N18 16.156 W063 08.891) – Located midway along northern coast of Seal Island. Flat pavement reef with scattered, mostly algae covered, old coral heads. Also some patches of dead Acropora palmata

and some small canyons. Many Grunts, Tangs and Parrotfish around this rubble. Site slopes up towards sea

rocks to the south, with gradual slope down into deeper water to the north. Few soft corals, but still classed

as mixed (pavement) reef community of low/medium complexity. Shot placed amongst area of coral

rubble.

PP05 (N18 15.934 W063 08.194) – Located past east of southern coast of Seal Island (Inner west of Long Reef). Gently sloping reef comprised mainly of low topology Montastraea annularis colonies

(mostly dead) interspersed among sandy/hard bottom with some algae cover. Shallow areas (3m) slowly

slope down to sandy bottom at around 10m, although the actual survey site only varies between 5 – 8.5

meters in depth. Mostly juvenile fish notes. Some soft coral and algae cover. Relatively high numbers of

Hamlets and many Three Spot Damselfishes (Stegastes planifrons) present. Classed as mixed reef

community of medium complexity. Shot placed among dead coral colonies at c6m.

22

PP06 (N18 15.741 W063 07.513) – Located almost midway along Long Reef (Inner). Very similar to PP05 although the gently sloping reef comprised mainly of Montastraea annularis colonies (mostly dead)

has slightly higher topological complexity with less sandy/hard bottom areas. Also seems to have a better

diversity of hard corals (some Staghorn (Acropora cervicornis) for example). Shallow areas (3m) slowly

slope down to sandy bottom at around 10m, although the actual survey site only varies between 6 – 8.5

meters in depth. Mostly juvenile fish notes. Some soft coral and algae cover. Relatively high numbers of

Hamlets and many Three Spot Damselfishes (Stegastes planifrons) present. Classed as mixed reef

community of medium complexity. Shot placed in small sand hole at c7m.

PP07 (N18 16.222 W063 06.269) – Located along Long Reef, towards it’s eastern end pretty close to the MV Sarah wreck. Some shallow areas of dead Acropora palmata, but some living colonies present also.

Also large colonies of Porites porites and Montastraea sp with finger coral being dominant. Other live hard

corals present – probably the highest percentage cover of all sites studies. Some scattered sand patches and

a good abundance and diversity of fish. A very pretty survey site. Classed as a hard coral dominated mixed

reef community of medium/high complexity. Shot placed in small sand hole near a large Montastraea sp

colony.

PP08 (N18 16.150 W063 05.525) – Located on the far western outer end of Long Reef. Shallow (3m) area with slope down to rocky/coral/sand plateau at 10m. Many dead, but also a number live, Acropora

palmata colonies. Many White Encrusting Zoanthids (Palythoa caribaeorum) present in shallower regions.

Strong current present. Good fish diversity, low levels of algae and some soft corals. Classed as mixed reef

community of high complexity. Shot places among dead coral colonies (midway down slope).

Dog Island Marine Park

DG01 (N18 16.526 W063 14.559) - Located midway along the southeastern coast of the island. Generally this region consists of pavement reef with scattered algae and the odd small ridge or small rock.

The location of this site was the same as this although it had more topological features than the immediate

surrounding area – such as a few small (20cm deep) ledges housing many lobsters; and a scattering of some

small rocks. For such low complexity this site had an abundance of fish – mainly grunts, goatfish,

surgeonfish and (interestingly) black bar solider fish. Classed as an algal pavement reef of low complexity.

Shot placed in small rubble covered depression surrounded by small ledges.

DG02 (N18 16.650 W063 16.392) – Located on the northeastern coast of West Cay. A very

topologically complex region with limited hard coral but many brightly coloured sponges. Some areas of

densely packed soft corals. Topology is not ‘complex’ here like mounds of Acropora palmata are for

example, rather highly three dimensional with tall rock peaks and trenches resembling a mountain range.

High fish diversity and abundance with many Black Durgeons, Grunts and Bar Jacks. Classed as a mixed

reef community of high complexity. Shot placed on top of a small plateau amidst the ‘mountains’.

DG03 (N18 17.142 W063 15.616) – Located near the southeastern coast of Mid Cay. A flat pavement

area slopes up and becomes covered in low lying hard corals (mixture of dead & alive). As this slope

gradually reaches it peak soft corals become more dominant. The peak then dips sea ward gradually into

the deep – this area is soft coral dominated. A good diversity and abundance of fish present. Classed as

mixed reef community of medium complexity. Shot placed in sand hole amongst the low lying hard corals

just prior to the slope peaking. It should be noted that on the relatively calm day this exposed site was

surveyed quite a strong current was present making work more difficult.

**See following page for a map illustrating the locations of these study sites**

23

24

Appendix II – Notes on Data Analysis and Limitations

Occurrence Categories (RDT)

Based on overall density if extrapolated into numbers seen per hectare of representative

habitat, where <1ha-1 is considered ‘rare’, <10 ha

-1 ‘Uncommon’, <150 ha

-1 ‘Occasional’,

<750 ha-1 ‘Common’ and >750 ha

-1 is ‘abundant’. These categories do not take into

account specifics of any particular species’ life history traits (i.e. being cryptic and

therefore problematic to accurately survey), nor are the categories based on prior research

as to what should be considered, for example, an abundantly occurring species. The

categories are merely a tool used within this report to provide qualitative results for a

species’ abundance, where in the results section the ‘most commonly occurring species’

are those that fall into the category of ‘abundant’. These categories also relate to hectares

of representative habitat and are not realistic when considering variations that can occur a

short distance away from a site. Hectares were used rather than square meters in order to

emphasize differences between sites. The exact figures that resulted from the RDT

surveys should be used for more detailed future analysis, although again any particular

species’ life history traits should be considered when drawing any conclusions. For

example many Damselfish (Pomacentridae) are often cryptic as are most Blennies

(Labrisomidae, Chaenopsidae, Blenniidae & Tripterygiidae) and Gobies (Gobiidae). In

many of these cases a mere presence/absence can be concluded rather than an accurate

abundance/density. It should also be noted that species were placed into different

abundance categories when submitting data to REEF depending on their tally per survey

conducted where: 1 = ‘one’, 2 – 10 = ‘few’, 11 – 100 = ‘many’, and >100 = ‘abundant’.

Relative Abundance (SPC)

Results were only worked out to a relative abundance value (individuals survey-1)

because in the methodology fish were counted within a five meter radius of the surveyor,

thus forming a sphere. Within this sphere, especially on sites that were characterized by a

steep slope, there might be a variety of habitats, including open water. For this reason it

was felt more appropriate to leave abundance relative. As it turns out most of these

figures were not used in the discussion section so this point is largely academic.

Underlying substrate categories (Habitat)

For the purpose of this project the underlying substrate was split into three categories

defined as: Solid – Rock or other consolidated hard material that does not move readily;

Rubble – Loose hard material ranging in size from pebbles to small boulders, although

they must be potentially movable (i.e. could shift location in a storm); and Sand – as

described. When categorizing the substrate the surveyor was encouraged to make

investigations to find out, for example, if sand was only a light covering over rock, and so

underlying substrate should therefore be classed as Solid. For this reason, and also due to

plants/algae overgrowing sand, the percentage cover in the underlying substrate section

may differ greatly to that in the sand percentage cover when making biotic/barren

assessment.

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Biotic or Barren (Habitat)

These categories of the habitat relate to the percentage cover of either flora, fauna or

barren (sand, sediment) characteristics over the underlying substrate. Initially a category

existed for bare rock, but as none was seen during surveys this was later disregarded.

Although rock can look bare a lot of the time it invariably is covered with either

sediment, turf algae, coralline algae or a mixture. Turf algae rarely exists on its own and

is usually accompanied with a dusting of sediment (sometimes a very heavy dusting),

hence why these two characteristics were grouped together. Coralline algae usually has a

covering of turf algae too, a fact that should be noted when considering the results from

this habitat work.

Note on depth limitation (General)

Because of replicate number surveys were not carried out in water deeper than ten

meters. With fewer logistical constraints it would have been more favorable to specify a

depth for a certain number of survey replicates (i.e. 5m, 10m & 15m – habitat

permitting). With the resources available it was felt advantageous to specify a depth

range for all surveys, but record the depth of each survey for use in later analysis.

Definition of ‘Health’ (General) This term is used in a general sense throughout this project, and is a qualitative measure

rather than quantative. For example, a site with high fish density and/or diversity may be

described as having a healthy fish population, although this may not necessarily be the

case (i.e. the dense population may be caused by a large school of Jacks passing through

and so not represent a high resident population). The term is also used when referring to

habitat, and is based loosely on high coral cover and low fleshy algae. Sediment may also

be seen as a negative characteristic, but high complexity (rugosity & relief) a positive

one. When the term has been used it is not based on any calculations or index of health

and so is used again in a qualitative sense. More detailed analysis may come to different

conclusions than have been drawn here regarding which sites were in fact the most

‘healthy’.

Variation of habitat types between study sites within Marine Parks (General)

For the most part of this report sites within each Marine Park are grouped together and

talked about in general terms. However, sites often varied greatly within each park and so

this grouping is not necessarily correct. For example, SB01 was flat pavement type reef at

a relatively constant depth with scattered coral colonies and soft corals where as SB02

was a more complex region sloping from 2m down to a depth of more that 15m, where it

then developed a sandy bottom. The reason sites have been grouped like this is because

of the general nature of this report, but when conducting a more detailed analysis it would

be an incorrect thing to do. This is the main reason for including site descriptions in

Appendix I, so that grouping can be made based on similar habitat

characteristics/geographic location. This document only represents a ‘report’ on work

conducted and brief discussion and is not meant to form the basis of management

decisions unless accompanied by a more detailed analysis and socioeconomic

assessments.

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Survey Numbers within Marine Parks (General)Each park had a varying number of

study sites, the amounts of which were chosen as described in the methods section.

However, although this was a wise thing to do for the most part, some artifacts may be

produced in the dataset as a result. For example, during the RDT surveys the number of

species recorded in a park as whole is likely to be higher if more sites are visited due to

the increased likelihood of sighting less common species. For a more realistic result each

park was given a diversity value based on the mean number of species seen within each

site across the park as a whole. It should be noted here that an actual diversity index was

not used in this report, which might prove beneficial if conducting a more detailed

analysis.

Data Inconsistencies (General)

Density discrepancies between the RDT surveys and SPC surveys such as that seen in

PP04. Reasons for this are unclear but are likely due to a mixture of reasons. For

example, the survey types look at different groupings of fish, so a higher RDT result than

SPC is likely caused by a huge school of fish not recorded using the SPC methodology,

for example, Wrasse (Labridae) or Chromis sp. In cases where SPC yields higher results

than RDT, the most likely scenario is caused by a school of fish, for example, Acanthurus

sp., swimming past the surveyor and not being sighted by the RDT surveyor. This latter

scenario would likely be solved by increasing survey replicate number. However, there

are other possible reasons that could be due to data handling/analysis. For example,

results from RDT & SPC methods may yield more similar results if both were split into

the same categories (i.e. RDT results grouped into fish families as SPC results were).

Another possible reason for this later discrepancy that would not be solved by increasing

replicate number would be double counting individuals. This is far more likely to happen

when using the SPC methodology than it is with RDT surveys because rather than

remaining in the same spot you swim over new habitat at all times. For this reason when

discussing results in this report SPC data are on the whole only used for size class

distributions (if double counting did occur then it is assumed it will be uniform across all

size classes and so not affect the distribution curve), and RDT data for density and

diversity purposes. On a few occasions however they are mentioned because they

highlight an interesting issue. It is not suggested that any future, more detailed statistical

analysis, should follow this course as it is probable that there are extremely valid and

correct reasons for this inconsistency, however, for the purpose of this report this is the

decision that was made.

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Appendix III – Example Datasheets: Roving diver datasheet (this page); Fish size class datasheet (second page following); Habitat quadrat datasheet (third page

following).

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References

Bythell J. (1995). The Anguillian Marine Resources Atlas. Natural Resources Institute,

University of Greenwich, Kent, UK.

Humann P. & Deloach N. (1989). ‘The Reef Set’. New World Publications.

Oxenford H.A. & Hunte W. (1990). ‘A survey of marine habitats around Anguilla, with

baseline community descriptors for coral reefs and seagrass beds’. Report for the

Department of Agriculture and Fisheries, Government of Anguilla, 177 pages.

Wynne S.P. & Côté I.M. (2007). ‘Effects of habitat quality and fishing on Caribbean

spotted spiny lobster populations’. Journal of Applied Ecology 44. p.488 – 494.

Documents

Ecological Baseline Survey of Anguilla’s Five Marine Parksgov.ai/documents/fisheries/Ecological_Baseline_Surveys_of_Anguilla… · Park before the survey work began in earnest