The evaluation of a recreational fishing stock enhancement ... · Swan River black bream have been maintained as broodstock at FMC since 1990. Broodstock have been maintained in seawater

FISHERIES RESEARCH REPORT NO. 124, 2000

The evaluation of a recreational fishing stock enhancement trial of black bream

(Acanthopagrus butcheri) in the Swan River, Western Australia

C.J. Dibden, G. Jenkins, G.A. Sarre, R.C.J. Lenanton and S.G. Ayvazian

Fisheries Research DivisionWA Marine Research Laboratories

PO Box 20 NORTH BEACHWestern Australia 6020

Fisheries Western Australia

Fisheries Research ReportTitles in the fisheries research series contain technical and scientificinformation that represents an important contribution to existing knowledge,but which may not be suitable for publication in national or internationalscientific journals.

Fisheries Research Reports may be cited as full publications. The correctcitation appears with the abstract for each report.

Numbers 1-80 in this series were issued as Reports. Numbers 81-82 wereissued as Fisheries Reports, and from number 83 the series has been issuedunder the current title.

EnquiriesFisheries Western Australia3rd floor SGIO Atrium168-170 St George’s TerracePERTH WA 6000Telephone (08) 9482 7333Facsimile (08) 9482 7389Website: http://www.wa.gov.au/westfish/res

Published byFisheries Western AustraliaPerth, Western AustraliaDecember 2000ISSN: 1035 - 4549ISBN: 0 7309 8450 8

An electronic copy of this report will be available at the above websitewhere parts may be shown in colour where this is thought to improveclarity.

Fisheries research in Western AustraliaThe Fisheries Research Division of Fisheries Western Australia is based at theWestern Australian Marine Research Laboratories, P.O. Box 20, North Beach(Perth), Western Australia, 6020. The Marine Research Laboratories serve asthe centre for fisheries research in the State of Western Australia.

Research programs conducted by the Fisheries Research Division andlaboratories investigate basic fish biology, stock identity and levels,population dynamics, environmental factors, and other factors related tocommercial fisheries, recreational fisheries and aquaculture. The FisheriesResearch Division also maintains the State data base of catch and effortfisheries statistics.

The primary function of the Fisheries Research Division is to provide scientificadvice to government in the formulation of management policies fordeveloping and sustaining Western Australian fisheries.

Contents

Page

Abstract ............................................................................................................ 1

1.0 Introduction .................................................................................................... 1

2.0 Methods .......................................................................................................... 2

3.0 Results .............................................................................................................. 4

4.0 Discussion ........................................................................................................ 5

5.0 Conclusions ...................................................................................................... 6

6.0 References ........................................................................................................ 7

7.0 Table and Figures .......................................................................................... 7

8.0 Appendices ...................................................................................................... 11Appendix 1: Tagged black bream release information ............................ 11Appendix 2: Press releases ...................................................................... 17Appendix 3: Tagged black bream recapture information ........................ 20Appendix 4: Recaptured tagged black bream biological information .... 22Appendix 5: Tagged black bream vs wild stock black bream

growth comparison .......................................................... 23

i

Fish. Res. Rep. Fish. West. Aust. 12000, 124, 1-23

The evaluation of a recreational fishing stockenhancement trial of black bream(Acanthopagrus butcheri) in the Swan River,Western Australia.

C.J. Dibden, G. Jenkins, G.A. Sarre, R.C.J. Lenanton, S.G. Ayvazian.

Abstract

During 1995, a study was undertaken to monitor and evaluate the recovery of SwanRiver black bream stock which had been supplemented with fish produced from acaptive-breeding program. Fish were individually tagged and subsequently releasedinto the Swan River. The objectives of the study were (a) to determine both thesurvival and the growth rate to a size at which hatchery-reared fish could enter therecreational fishery and (b) whether they could then be caught by the recreationalfishers. Of the 767 fish released into the upper Swan River on 28 March 1995, 97 fish(12.6%) were recaptured to the end of October 1997.

The results from this initial study show that captive-bred black bream released intothe Swan estuary can survive and grow in the wild and may also be more catchablethan wild fish. The results also show that captive-bred fish introduced into the wildcan ultimately contribute to the recreational black bream fishery.

1.0 IntroductionIn 1993, the Western Australian Recreational and Sport Fishing Council (WARSFC) sponsoreda Landcare Environmental Action Programme project based at the South Metropolitan Collegeof TAFE’s Fremantle Maritime Centre (FMC). The “Mariculture Restocking Programme”, asit was known, had as one of its initial aims, the production of juveniles for use in the restockingof marine recreational finfish resources, and, at the same time, training students in techniquesused in the aquaculture industry.

Tarwhine (Rhabdosargus sarba) was the first species targeted by this project. Juveniles grownfrom fertilised eggs, collected from Underwater World at Sorrento Quay and raised at FMC,were released into wild marine populations off the Perth metropolitan area. Besides ensuringthat juveniles released into wild populations were produced from broodstock from thatpopulation and that all juveniles were disease free, no attempt was made to evaluate the successof these releases.

Subsequently during 1995, WARSFC proposed that, in association with FMC, FisheriesWestern Australia (FWA) and Murdoch University (MU) Fish Group, hatchery-bred SwanRiver black bream (Acanthopagrus butcheri), which had been successfully raised at FMC forseveral years, be released into the Swan River. Acanthopagrus butcheri was chosen as it is arelatively easy species to breed in captivity, is extremely hardy and is considered to be one ofthe most important recreational species in Western Australia (Potter et al. 1996). The SwanRiver was selected for these trials, not because the bream stock in this system was consideredbadly depleted, but because of the proximity of the river to FMC, the high recreational anglingpresence within this system with its close proximity to the capital of the State, and theopportunity to readily access data from angler caught tagged fish.

2 Fish. Res. Rep. Fish. West. Aust.2000, 124, 1-23

After consultation with FWA, it was decided that, in the first instance, in order to monitor thesuccess of introducing captive-bred black bream into the Swan River for stock enhancement,the fish should be grown to a size (at least 12 months old) that would enable them to beindividually marked with external tags. All juveniles were produced from Swan Riverbroodstock, and were to be certified free of disease prior to release. The monitoring of therecaptures was to be undertaken by FWA, with MU Fish Group providing additional resources.The monitoring was intended to provide data on the survival and growth of the captive-bredfish present in recreational angler catches, and acceptance by the anglers of these fish relativeto wild-stock fish (e.g. fighting qualities, appearance, taste). Thus, the primary purpose of thisstudy was to monitor the recovery of individually tagged captive-bred black bream releasedinto the Swan River, to determine their survival and growth rate to a size at which they enteredthe recreational fishery (minimum legal size), and whether they are vulnerable to capture bythese fishers.

This report presents the results of this study, together with all validated data sets which maybe needed for more detailed analyses in the future.

2.0 MethodsSwan River black bream have been maintained as broodstock at FMC since 1990. Broodstockhave been maintained in seawater at 35 ppt in a flow-through system and fed on a fresh dietsupplemented with vitamins. The first eggs for culture trials were collected from these fishwith the aid of hormones (HCG) in 1993. Black bream broodstock have subsequently spawnednaturally since 1994, producing over 90 million eggs from December to February each year(Jenkins 1995).

Black bream larvae were reared intensively in 5,000 litre cylindroconical fibreglass tanks atFMC in 35 ppt seawater. The larvae were initially fed a diet of rotifers at a rate of four to 10 rotifers per ml, with the algae Nannochloropsis oculata being maintained at an average celldensity of 500,000 cells per ml during this period. When larvae reached an average length of7 mm, they were weaned onto a diet of Artemia over a six-day period. Artemia were then fedto the larvae at a rate of 0.4 per ml until the larvae reached an average length of 10 mm. Larvaewere then weaned onto micro-pellets over a 10-day period. The micro-pellet diet wascontinued until the juvenile stage was reached. Juveniles were subsequently fed a Nippia-MLpellet diet.

During 1995, a large number (thousands) of juvenile black bream from the 1994 breedingprogram were made available for the stock enhancement trial. One week prior to release, 775of the 14-month-old black bream were individually marked with an external plastic T-baranchor tag. The weight (gm) and fork length (mm) of each fish were also recorded whentagged (Appendix 1). During the tagging process, the fish were anaesthetised with Benzocaineat 50 ppm and the T-bar inserted between, and locked behind, the dorsal pterygiophores of thefish. The tags had a yellow cylindrical body on which instructions for return were inscribed.Fish were maintained at FMC for one week after tagging to ensure that the tags were secureand that all fish to be released had recovered from the process.


Most (767) of these fish were released into the Swan River at the south side of Ron CourtneyIsland (Figure 1), on 28 March 1995. The fish release was publicised through the media(Appendix 2) with recreational anglers being encouraged to contact the Coastal/EstuarineBranch of FWA Research Division and provide details of the recapture, in return for a reward(a “Scratch and Win” lottery ticket, provided by the WA Lotteries Commission).

Anglers that reported black bream recaptures to FWA were asked to provide the followinginformation: tag number, date caught, recapture site, details of gear used, and demographicinformation relating to each angler (Appendix 3). Recaptured fish were classed as:

1. Fish and Tag return if the whole fish or filleted frame, and the tag were returned.

2. Tag Only return if only the tag was returned.

3. Re-Release if the tag was left intact and the number recorded and the fish was returned tothe water.

The recapture site information for the Fish and Tag returns, Tag Only returns and Re-Releases,was used to calculate the distance travelled (in metres) by the black bream from the releasesite, using an estimated river centreline as the standard path travelled. The number of days atliberty was determined by simply subtracting the release date from the recapture date. Thenumber of days at liberty was used to estimate the age of each fish recaptured by adding thetime at liberty to the age at release in months [i.e. age = time at liberty + release age].

The daily rainfall for the period 22/03/95 (just prior to release) through to 31/10/97 for thePerth area was extracted from Bureau of Meteorology monthly reports. This information wasused to examine the possible effect of rainfall (and thus river flow) on tagged black breammovements in the river.

Angler demographics were used to determine the distribution of residential locations of therecreational anglers that caught tagged fish.

Whole fish and filleted frames that were returned to FWA, were forwarded to the MU Fish Group for detailed biological examination. On examination, each fish was measured (TL ± 1 mm). Reproductive organs, where available, were dissected and stored in Bouinssolution for subsequent histological examination. Alimentary canals were removed and storedin 70% ethanol. Stomach fullness, on a scale from 1 to 10 (distended), was estimated andcontents examined under a binocular microscope. Each dietary item was identified to thelowest possible taxon. The percentage frequency and the relative contributions of each dietaryitem to the total number in the stomach of each fish was calculated. Volumes of dietary itemswere expressed using the ‘points’ method (Hynes 1950, Hyslop 1980), which takes intoaccount stomach fullness. Since volumetric data best represent the relative importance of anyparticular dietary category, especially in cases where advanced digestion of some prey maymake it difficult to identify the number of individuals of a prey species (Hyslop 1980),subsequent analyses were performed using only volumetric data of the dietary categories.

The age of each returned tagged black bream was extrapolated from its known hatchery birthdate if the recovery date was known.


3.0 ResultsOf 767 fish tagged and released, 97 fish were recaptured (Appendix 3) to 31 October 1997. Ofthese, 40 were returned as Fish and Tag returns, 40 were Tag Only returns and 17 were Re-Released (Table 1). There were also reports of the capture of a further 11 tagged fishsubsequent to 31/10/97, however, as recapture details could not be confirmed, these fish werenot considered in the analyses. Further, three of the Re-Released fish have since beenrecaptured and, together with tags, returned intact to FWA. This relatively high recapture rateprovides direct evidence that hatchery-reared fish can survive long durations in the wild.

Examination of the recapture and release data in arbitrary distances both downstream andupstream from the release site (Figure 1) showed that of the 97 fish recaptured, 23 fish werecaught within 2 km of the release site, 34 fish between two and 10 km of the release site,24 fish between 10 and 15 km of the release site, and 16 fish were caught at a distance greaterthan 15 km from the release site. Sixty-two of the fish were caught upstream of the releasesite, four fish were recaptured near the release site and the remaining 31 fish downstream. Thegreatest recapture distances were 42 km downstream and 25.4 km upstream from the releasesight. The average recapture distance from the release site was 2.1 km upstream. The leastnumber of days at liberty was nine, the greatest was 945 and the average was 317 days (Table1).

The location of fish recaptures did appear to be influenced by the magnitude of the winterrainfall (≈ river flow). After the first substantial rains for 1995 (during mid-May) and duringthe ensuing winter (June and July), 71% of the recaptured fish were caught downstream of therelease site (Figure 2). During the spring and summer period after the last rains for 1995, agreater proportion of the recaptures were taken upstream of the release site. However, withinthe first 12 months after release, there was no statistically significant correlation (R2 = -0.04)between daily rainfall and recapture site (expressed as distance from the release site) (Figure2). It is difficult to determine the extent to which the spatial pattern of recaptures was relatedto the distribution of fish and angler effort. It could be assumed that both the distribution offish and anglers varies with season.

Forty fish were returned (32 whole and eight others). Of these 40 fish, three were recapturedwithin 46 days of release and showed no increase in length. The remainder increased in lengthby as little as 2 mm and as much as 58 mm (Appendix 4). As expected, the greatest increasesin length and weight were observed in fish that were at liberty the longest.

The lengths and estimated ages of the only recaptured fish for which there were adequate data,i.e. nine males and 14 females, were fitted to von Bertalanffy growth curves developed byPotter et al. (1996), and compared with the equivalent cohort of wild Swan River black breamusing a Students T-Test (Appendix 5). There was a statistical difference (p < 0.05) betweenthe length-age relationships, with the lengths of the captive-bred fish which had been grown inoptimum laboratory conditions for 14 months being greater for the ages examined than wild-caught fish.

Dietary analysis of the 22 fish examined with food in their stomachs and intestines (Appendix4), showed that prey items included bivalve mussels (Swan River Mussel, Xenostrobus sp.,another small bivalve, Tellina deltoidalis, and the small brown bivalve Arthritica semen), theamphipod Paracorophium excavatum (approximately 5 mm in size), some plant material,polychaetes (the Swan River bloodworm Marphysa sanguinea) and prawn pieces. These last


two prey items were most probably bait used to catch the fish. Each of these prey items hadbeen shown to be present in the diet of wild stock Swan River Black bream (Potter et al. 1996).Twelve of the fish examined had empty guts, but six of these had prey items in the intestine.

Fifteen of the fish were determined to be male (TL 142 mm to 253 mm) and seventeen fishwere determined to be female (TL 163 mm to 253 mm). The remaining fish could not be sexedas no gonads were retained. Analysis of available gonads indicated that three males (lengths184 mm, 191 mm and 234 mm, aged 1.6 yrs, unknown age, and unknown age, respectively)and two females (lengths 236 mm and 253 mm, aged 1.9 yrs and unknown, respectively) weresexually mature with gonads of stage 5 (Appendix 4). However, most recaptured fishexamined were not mature, either because they were recaptured outside the spawning period,or because they had yet to reach the length of maturity. The lengths and ages of these fish werecomparable with the lengths and ages for sexually mature Swan River wild-stock black bream(Potter et al. 1996).

A number of anglers who returned tagged fish also reported wild fish in their catch, however,most of these had relatively few wild fish in their catch. Few recreational fishers reportedrelatively large numbers of wild fish in catches that included tagged fish (usually only a singletagged fish). However, a high proportion (34%) of individual angler catches contained one ortwo tagged bream as the sole catch. These data suggest that tagged black bream were morecatchable than individuals from the wild population. The geographical distribution of therecreational fishers that reported catching tagged black bream were mainly from suburbswithin 10 kilometres of the Swan River, on the upstream side of Perth city (Figure 3).

For reasons of confidentiality, the names of the people that reported tag recaptures toresearchers cannot be published, but there were 76 individuals who provided information, withone person catching five tagged fish, two people catching four tagged fish, two people catchingthree tagged fish and seven people catching two tagged fish (Table 1). Several of the 76respondents commented that they were fishing specifically for black bream in the Swan Riverand had “special hot-spots” that they targeted depending upon the time of day and weatherconditions prevailing at the time, and that the fish that they caught had “fought” like a fish ofmuch greater size.

4.0 DiscussionThe results from this initial study show that captive-bred black bream released into the Swanestuary can survive and grow in the wild for at least three years. The prey items present in thestomachs and intestines of those fish examined, were also present in wild-stock Swan Riverblack bream (Potter et al 1996). This would suggest that captive-bred black bream are capableof foraging for prey items that constitute a natural diet. When compared with the wild fish,growth rates of the captive-bred fish indicate they grew at least as well as the wild fish in theSwan River, suggesting they have adapted well to their natural environment.

The results of this study also show that captive-bred fish introduced into the wild do contributeto the recreational black bream catch (97 recreational recaptures reported to 31 October 1997,out of a possible 767 released fish, i.e. 12.6% recaptured).

Unfortunately, the total numbers of wild-stock black bream caught over the same period oftime by recreational fishers were not available, precluding a direct comparison between themagnitude of catches of wild-stock black bream and captive-bred black bream. Such a


comparison could have revealed any differences in the ability of anglers to catch hatchery-bredfish relative to wild stock, which is an important consideration for recreational fisheriesmanagers (i.e. are the captive-bred fish more or less catchable when compared with wild fish).However, from the small number of anglers that provided total catch composition informationwith fish recapture reports, it appeared that the hatchery-bred fish may be more catchable thanwild fish. There are also no data available on the spatial and temporal distribution ofrecreational fishing effort during the period of the study. This lack of recreational catch-effortdata makes the precise interpretation of fish movement from the recapture data difficult.Nevertheless, the available results appeared to indicate that the captive-bred fish behavedsimilarly to wild fish in response to annual events such as winter rains. Some knowledge ofhow the captive-bred fish responded to the intrusion of marine water into the Swan Riverwould also have assisted in deciding how well the fish have adapted to their naturalenvironment. The important point here is, the better the stocked fish adapt to the naturalestuarine environment, the greater the chance of survival, with the ultimate result that more fishare likely to become available in the recreational fishery.

5.0 ConclusionsThis initial recreational stock enhancement trial has shown that captive-bred fish growninitially to about 15 cm in the hatchery, and then introduced into the wild, can ultimatelycontribute to the recreational fishery. However, several further issues need to be considered,these include:

To what extent can the introduced hatchery-bred fish enhance the recreational fish stocks? Partof the answer to this question involves an assessment of whether younger, smaller, and hencecheaper to produce, juvenile black bream will survive equally well in the wild and ultimatelycontribute to the recreational fishery.

There is also the important issue of the quantification of the cost and benefit of stocking blackbream in the Swan River.

The ability of introduced fish to quickly adapt to a natural diet is likely to be a telling factorinfluencing their rate of survival. This factor will assume greater importance if smaller fish arereleased as mortality of smaller fish is generally higher than that of larger fish.

In an attempt to address some of these issues, a second restocking trial in the Swan River wasundertaken. The FMC and FWA released approximately 30,000 small, juvenile black bream(< 70 mm TL) into the Swan River. Fish were tagged using a fluorochrome dye,oxytetracycline, and released at a much smaller, and thus more cost-effective size.Unfortunately, the planned comprehensive monitoring program to evaluate recreational angler-caught fish returns, commencing between 18 months and 2 years post-tagging, could not beundertaken due to lack of funding.


6.0 ReferencesHynes, H.B.N. (1950). The food of fresh-water sticklebacks (Gasterosteus aculeatus and

Pygosteus pungitius), with a review of methods used in studies of the food of fishes.Journal of Animal Ecology 19,39-58.

Hyslop, E.J. (1980). Stomach contents analysis - a review of methods and their application.Journal of Fish Biology 17, 411-429.

Jenkins, G. (1995). Aquaculture potential of the black bream (Acanthopagrus butcheri).ACWA News, April 1995, 9, 16-18.

Potter, I.C., Hyndes, G.A., Platell, M.E., Sarre, G.A., Valesini, F.J., Young, G.C. and Tiivel,D.J. (1996). Biological data for the management of competing commercial andrecreational fisheries for King George whiting and black bream. Fisheries Research andDevelopment Corporation Report, FRDC Project 93/82. School of Biological andEnvironmental Sciences, Murdoch University, Murdoch, W.A.

7.0 Table and Figures

Table 1 Summary of information from tagged black bream tag recaptures reported prior to31 October 1997.

Fish and Tag returns (includes two Re-Released fish) 40 fishTag Only returns 40 fishRe-Released fish 17 fishTotal 97 fish

Distance from Ron Courtney Is. release site:Furthest upstream 25.4 kmFurthest downstream 42.0 kmAverage recapture distance 2.1 km downstream

Days at liberty for recaptured fish:Least number of days 9 daysGreatest number of days 945 daysAverage number of days 317 days

Number of recreational anglers that reported catching tagged fish:Five fish 1 personFour fish 2 personThree fish 2 peopleTwo fish 7 peopleOne fish 64 people

8Fish. R

es. Rep. Fish. W

est. Aust.

2000,124,1-23

Figu

re 1T

he tag

release and

recaptu

re locatio

ns o

f black b

ream in

the S

wan

River sto

cken

han

cemen

t trial.

1

5

3

1

4

1

n

1

1

2

1

1 2

2

1

n

1

4

n

n

1

24

5

24

3

6

16

15

6

2

-42 km@ Kent St weir

-36 km@ Wadjup Pt

Shelley

-27 km@ South Perth

Yacht Club

-21 km@ Narrows

-1 km

-10 km-2 km

1 km

2 kmReleaseLocation

10 km

Causeway

BunburyBridge Garratt Rd

TonkinHwy

Guildford Rd

PickeringPark

West Swan Rd

Kings MeadowOval

CavershamHouse

MiddleSwan

Rd

15 km

>15 km

25 km@ Henley BrookRottnest Is

Study Area

Perth

<

-15 km<

<<

<

<

<<

N

Release Location, Ron Courtney Is, 767 tagged fish released on 28/03/95.

Pre-winter 1995 recapture sites, where 'n' = number recaptured.

Winter 1995 recapture sites, where 'n' = number recaptured.

Post-winter 1995 to 30/10/96 recapture sites, where 'n' = number recaptured

31/10/96 to 31/10/97 recapture sites, where 'n' = number recaptured

X km Distance from release site at recapture (negative numbers indicate recapture downstream and positive numbers indicate recapture upstream of release site)

SCALE

0 2 km

>-15 km

Fish. Res. Rep. Fish. West. Aust.92000,124,1-23

Figure 2Daily rainfall in the Perth metropolitan area and distribution of recaptured blackbream relative to the place of release for the period 22/03/95 to 31/10/95.

Date

-30000

-20000

-10000 0

10000

20000

30000

0 10 20 30 40 50 60 70 80First su

bstan

tial rains

28/03/95

19/04/95

11/05/95

02/06/95

24/06/95

16/07/95

07/08/95

29/08/95

20/09/95

12/10/95

03/11/95

25/11/95

17/12/95

08/01/96

30/01/96

21/02/96

14/03/96

05/04/96

27/04/96

19/05/96

10/06/96

02/07/96

24/07/96

15/08/96

06/09/96

28/09/96

20/10/96

Distance (m)

Rainfall (mm)

UPSTREAMDOWNSTREAM

R2 = -0.04

Fish recap

tures

Rain

fall


Figure 3 Spatial distribution of the residential locations of recreational fishers that reportedcatching tagged black bream.

116oE

32oS

3 fishers > 10 km from river

2 fishers > 10 km from river

1 fisher > 10 km from river

1 fisher < 10 km from river




N

3 0 3 6 kilometers

Clarkson

Ballajurra

Kingsley

Greenwood

Duncraig Girrawheen

Balga

Balcatta

Beechboro

Noranda

MorleyDianella

Lockridge

Eden Hill

Henley BrookHerne Hill

Middle Swan

Caversham

Bassendean

Swan ViewMidlandWest Midland

GuildfordBellevue

HazelmereSouth Guildford

Helena Valley

Maida Vale

High Wycombe

AscotBelmont

Cloverdale

Maylands

RivervaleCarlisle

Kewdale

ForrestfieldKensington

South Perth

Wembley

North Bridge

Coolbellup

Willeton

Armadale

Gosnells


8.0 AppendicesAppendix 1 Tagged black bream release informationTag Fork Length Weight CommentNumber (mm) (g)

0001 147 860002 176 1300003 142 64 Tag lost0004 153 900005 141 66 Tag lost0006 191 1660007 173 1350008 153 1060009 155 890010 155 900011 150 850012 155 870013 155 870014 157 98 Tag lost0015 155 970016 190 1640017 160 1020018 169 1430019 146 810020 170 1240021 150 1030022 146 890023 168 1250024 160 1090025 150 750026 145 900027 150 890028 185 1480029 156 950030 166 1160031 161 1160032 157 920033 168 1150034 173 143 Tag lost0035 158 108 00360036 165 1080037 152 880038 165 1210039 173 1330040 145 730041 160 980042 168 1200043 133 590044 169 1190045 167 1120046 147 810047 160 1020048 187 1680049 165 1220050 164 970051 163 1200052 Tag damaged0053 150 810054 165 1130055 186 1520056 145 720057 152 990058 165 1110059 153 1120060 155 920061 155 910062 173 1400063 177 1430064 155 1020065 141 80

Tag Fork Length Weight CommentNumber (mm) (g)

0066 160 1000067 130 750068 140 520069 174 1260070 161 950071 193 1660072 161 1050073 140 660074 157 970075 151 840076 164 1170077 150 1700078 134 540079 153 830080 165 1050081 142 640082 148 820083 139 630084 160 1020085 155 960086 145 81 Tag lost0087 145 800088 157 900089 160 970090 162 1040091 184 1440092 150 780093 158 1020094 169 1400095 141 660096 177 1360097 132 610098 166 1090099 186 1600100 165 1060101 160 1100102 140 710103 165 1070104 191 1620105 136 570106 167 1180107 166 1270108 162 1000109 135 560110 175 1290111 174 1120112 159 1100113 176 123 2 Tags0114 175 1140115 163 1060116 138 610117 122 420118 156 910119 153 860120 135 620121 137 700122 131 460123 183 1620124 140 590125 160 990126 182 1480127 149 880128 155 940129 166 107 2 Tags0130 168 117



0131 152 840132 156 970133 152 850134 126 450135 184 1460136 145 760137 138 760138 152 920139 167 1230140 135 680141 180 1390142 160 960143 160 1050144 164 1070145 151 780146 176 1410147 154 940148 161 1080149 148 970150 153 840151 180 1430152 152 870153 168 1270154 172 1240155 158 940156 154 950157 155 960158 155 900159 122 460160 145 770161 165 1020162 162 1080163 183 1480164 152 1020165 170 1210166 136 570167 171 1110168 163 1090169 167 1180170 162 1150171 173 1410172 148 850173 142 750174 157 980175 190 1750176 159 910177 145 730178 165 1230179 177 1320180 154 850181 151 810182 175 1330183 150 960184 165 1110185 152 780186 155 890187 162 1210188 185 1050189 135 600190 170 1170191 169 1100192 174 1160193 157 970194 160 1000195 162 101 Ab Tag0196 156 97


0197 138 650198 Tag damaged0199 140 720200 163 1030201 160 880202 149 830203 144 630204 160 970205 198 1930206 173 1350207 161 1050208 155 870209 150 760210 160 1020211 138 740212 150 800213 162 1180214 172 1290215 164 1050216 177 1510217 160 1150218 150 830219 145 760220 188 1330221 182 1500222 160 1020223 170 1210224 152 850225 158 970226 160 1030227 145 850228 154 980229 191 1640230 156 830231 145 700232 180 1470233 164 1090234 160 950235 142 640236 143 740237 152 850238 155 970239 154 1010240 168 1120241 160 1100242 169 1020243 153 880244 171 1340245 162 1180246 160 1040247 144 710248 160 1020249 158 980250 164 1170251 148 920252 160 990253 163 960254 154 890255 160 1060256 162 1080257 163 1170258 180 138 2 Tags0259 142 560260 155 960261 146 780262 165 98

Appendix 1 Tagged black bream release information (continued)



0263 179 1570264 172 1220265 172 1200266 159 930267 139 700268 150 760269 155 940270 162 1020271 164 1030272 152 750273 154 980274 137 550275 164 1080276 129 490277 155 88 Tag lost0278 147 700279 142 590280 165 1190281 167 1320282 152 980283 147 720284 203 2040285 139 740286 180 1420287 154 890288 138 780289 156 860290 179 1670291 180 1370292 171 1220293 162 1080294 163 1140295 165 1230296 145 710297 162 1060298 173 1220299 190 1650300 161 960301 165 101 Tag lost0302 175 1400303 155 77 Tag lost0304 147 790305 145 700306 155 920307 165 1090308 147 740309 137 640310 151 790311 151 790312 167 1010313 146 880314 165 1050315 162 1130316 159 1040317 155 1010318 169 1150319 155 870320 143 660321 149 740322 167 1230323 154 850324 159 1020325 149 750326 145 680327 167 1160328 149 76


0329 147 910330 133 660331 155 1000332 175 131 Tag lost0333 141 670334 169 1090335 160 910336 165 1060337 144 640338 165 1150339 167 1260340 153 810341 159 1170342 152 1080343 169 1120344 143 710345 160 1020346 155 840347 165 1180348 152 1120349 150 890350 159 880351 140 580352 155 480353 160 88 Mort0354 164 960355 160 1030356 160 99 Mort0357 160 980358 167 1340359 170 116 Mort0360 178 1340361 148 770362 150 850363 138 680364 170 1110365 163 1100366 166 1080367 147 750368 175 1410369 181 1310370 155 860371 143 760372 164 1180373 170 1130374 160 1210375 160 101 Mort0376 164 890377 150 700378 164 970379 165 1020380 160 1010381 151 840382 179 1520383 175 1250384 153 870385 162 1040386 160 1020387 155 910388 150 800389 171 1220390 156 910391 153 890392 165 1020393 161 950394 160 101




0395 167 1130396 153 900397 182 143 Tag lost0398 150 740399 162 840400 144 710401 164 1040402 161 1090403 120 38 Tag lost0404 164 1080405 128 410406 168 1200407 152 900408 171 1240409 140 830410 155 1110411 191 1580412 167 1040413 163 1140414 175 1520415 167 1030416 174 1280417 165 990418 123 36 Tag lost0419 132 540420 163 1230421 161 1020422 180 1500423 167 1170424 158 1020425 148 720426 160 1040427 161 1030428 165 1020429 152 920430 187 1620431 157 1070432 159 850433 152 920434 150 730435 164 970436 147 860437 157 940438 155 970439 154 840440 172 1260441 163 970442 164 1040443 148 760444 175 1340445 150 850446 142 680447 163 1100448 173 1180449 200 1900450 166 1160451 147 800452 153 95 Tag lost0453 165 1210454 170 1040455 152 820456 160 94 Tag lost0457 150 810458 159 890459 149 760460 168 118


0461 172 1380462 140 640463 160 980464 158 960465 152 680466 186 144 Mort0467 161 1080468 186 1480469 136 540470 148 780471 165 1110472 160 890473 155 750474 165 110 Mort0475 149 750476 180 1440477 154 900478 166 1020479 150 900480 191 1730481 164 1170482 179 1360483 168 124 Tag lost0484 157 940485 152 910486 158 1040487 181 1410488 173 1050489 172 1110490 152 940491 187 1520492 175 1330493 169 1210494 151 800495 163 1170496 149 830497 152 810498 155 990499 166 1220500 171 1310501 150 810502 143 660503 139 1370504 145 740505 156 900506 185 1370507 185 1620508 165 1080509 170 1170510 179 1350511 164 1060512 162 880513 176 1330514 155 900515 171 1270516 160 890517 165 1190518 167 960519 161 103 Tag lost0520 158 910521 140 630522 158 1040523 195 1840524 158 89 Tag lost0525 165 1080526 170 116




0527 154 900528 151 770529 182 1250530 163 1070531 160 890532 174 1240533 138 79 Tag lost0534 170 1350535 160 1060536 155 89 Tag lost0537 164 990538 166 1120539 163 1000540 183 1490541 165 1050542 151 810543 175 1290544 147 770545 159 102 Tag lost0546 170 1130547 162 940548 147 720549 154 870550 178 1360551 135 530552 145 680553 164 900554 166 1210555 175 1280556 175 1180557 130 400558 169 1300559 161 890560 185 1500561 170 1210562 152 900563 164 1000564 154 900565 122 400566 164 1120567 207 2150568 120 38 Tag lost0569 174 1410570 165 1140571 150 850572 143 800573 181 1280574 166 1030575 152 830576 146 690577 140 650578 175 1210579 167 1120580 192 1460581 161 1100582 154 770583 160 1110584 144 680585 163 117 Tag lost0586 152 900587 155 840588 172 1480589 167 1040590 165 1010591 150 840592 172 122


0593 175 1180594 188 1680595 160 950596 137 820597 162 980598 150 820599 164 1070600 175 135 Tag lost0601 169 1160602 164 75 2 Tags0603 154 850604 162 1160605 155 960606 167 1080607 176 1240608 154 960609 168 1100610 158 980611 179 1350612 147 760613 153 970614 175 1300615 147 870616 129 530617 142 720618 157 930619 162 980620 168 1200621 156 960622 171 1160623 157 1100624 170 1050625 174 1280626 139 610627 152 870628 155 800629 197 1870630 160 1000631 145 680632 168 1030633 149 830634 174 1260635 157 950636 159 840637 168 1200638 169 1180639 165 1080640 159 930641 166 1120642 153 770643 190 1660644 171 1160645 165 1010646 166 1050647 145 800648 168 1150649 125 410650 151 820651 163 1020652 167 1100653 148 880654 154 790655 175 1340656 148 840657 154 830658 161 92




0659 180 1370660 159 900661 152 830662 164 1070663 172 1270664 160 850665 163 970666 165 1210667 137 770668 160 970669 148 900670 180 1310671 154 790672 133 530673 164 1100674 178 1380675 173 1170676 159 1230677 169 1090678 182 1320679 153 860680 141 640681 172 1120682 188 1690683 152 880684 175 1350685 155 990686 160 980687 149 750688 160 980689 145 820690 169 1130691 175 1280692 184 1480693 177 1390694 153 880695 150 880696 160 910697 176 1350698 133 510699 160 1050700 164 1070701 160 950702 125 440703 129 710704 166 1050705 149 690706 150 780707 180 1360708 150 840709 154 840710 155 740711 125 590712 170 1130713 173 1050714 134 520715 170 1200716 150 880717 184 138



0718 149 810719 185 1360720 147 710721 174 1390722 165 1250723 155 960724 170 1230725 155 910726 150 830727 148 740728 154 830729 160 970730 172 1170731 159 960732 150 800733 162 960734 172 1110735 149 820736 192 1680737 165 1050738 187 1500739 151 900740 142 680741 155 910742 181 1400743 159 1010744 165 970745 174 1260746 180 1370747 Tag damaged0748 162 1030749 165 1050750 141 790751 160 990752 162 980753 135 760754 173 1160755 145 680756 130 47 Tag lost0757 140 610758 140 640759 166 118 Tag lost0760 178 1300761 161 1070762 148 68 Tag lost0763 166 1180764 169 1200765 127 670766 165 1050767 154 900768 160 910769 161 1040770 169 1340771 196 1740772 171 1110773 145 760774 179 1430775 153 83


Appendix 2 Press releases


Appendix 2 Press releases (continued)




Appendix 2 Press releases (continued)


Appendix 3 Tagged black bream recapture information

Tag no. Date Recapture Suburb Days Increase Distance Seasonof status of at in length from release

capture fisher liberty (mm) site (m)

0015 06/04/95 TO South Guildford 9 - 3277 Autumn0018 06/04/95 FT South Guildford 9 3 3277 Autumn0020 06/04/95 FT Girraween 9 0 3277 Autumn0696 08/04/95 FT Lockridge 11 0 -1721 Autumn0040 14/04/95 TO South Guildford 17 - 3650 Autumn

0722 02/05/95 FT West Midland 35 2 16400 Winter0529 13/05/95 FT Caversham 46 0 8273 Winter0157 14/05/95 FT Ascot 47 9 -2205 Winter0538 14/05/95 FT Balga 47 9 3650 Winter0061 18/05/95 TO Beechboro 51 - 5035 Winter0434 28/05/95 FT South Perth 61 13 -14331 Winter0648 28/05/95 FT South Perth 61 6 -14331 Winter0134 04/06/95 TO Greenwood 68 - -14331 Winter0074 06/06/95 FT Morley 70 8 -14128 Winter0482 06/06/95 FT Bassendean 70 9 -14331 Winter0187 17/06/95 RR Rivervale 81 - -6500 Winter0370 18/06/95 RR Rivervale 82 - -1721 Winter0050 04/07/95 TO Kensington 98 - -17696 Winter0452 19/07/95 TO Maylands 113 - -5285 Winter0464 27/07/95 TO Coolbellup 121 - 3277 Winter

0581 29/08/95 RR 154 - -27158 Spring0165 19/09/95 FT Midland 175 14 10937 Spring0236 20/09/95 FT Middle Swan 176 12 12271 Spring0291 20/09/95 FT Henley Brook 176 11 12271 Spring0140 22/09/95 FT Middle Swan 178 7 12271 Spring0117 28/09/95 RR Midland 184 - 12271 Spring0764 06/10/95 RR Kewdale 192 - 3650 Spring0106 15/10/95 RR Beechboro 201 - -1004 Spring0448 29/10/95 FT Noranda 215 - 1676 Spring0579 29/10/95 FT Noranda 215 - 1676 Spring

0029 04/11/95 FT Noranda 221 - 12271 Summer0180 04/11/95 FT Noranda 221 - 1676 Summer0219 04/11/95 FT Balcatta 221 - -1721 Summer0340 04/11/95 FT Noranda 221 - 12271 Summer0347 04/11/95 FT Noranda 221 - 1676 Summer0108 09/11/95 FT Henley Brook 226 - 8273 Summer0266 09/11/95 FT South Guildford 226 13 5300 Summer0311 12/11/95 RR Bellevue 229 - 6105 Summer0594 25/12/95 FT Gosnells 272 25 -1004 Summer0249 27/12/95 RR Willeton 274 - 8273 Summer0072 01/01/96 TO Balcatta 279 - -7081 Summer0123 01/01/96 RR 279 - 3277 Summer0143 01/01/96 TO Balcatta 279 - -7081 Summer0622 04/01/96 TO Bassendean 282 - 0 Summer0775 05/01/96 TO Armadale 283 - -757 Summer0261 10/01/96 TO Bassendean 288 - 12271 Summer0616 13/01/96 TO SwanView 291 - 16050 Summer0319 15/01/96 TO Beechboro 293 - 5655 Summer0181 17/01/96 FT Midland 295 45 5655 Summer0382 23/01/96 TO Helena Valley 301 - 5035 Summer0588 27/01/96 FT Middle Swan 305 33 15084 Summer

0058 01/02/96 TO Belmont 310 - -1721 Autumn0300 01/02/96 FT Carlisle 310 45 1676 Autumn0104 02/02/96 FT Middle Swan 311 45 14200 Autumn0184 18/02/96 FT Noranda 327 57 10400 Autumn0684 19/02/96 FT Herne Hill 328 57 16050 Autumn0106 20/02/96 FT Kewdale 329 53 -2265 Autumn0031 27/02/96 TO Duncraig 336 - 13558 Autumn0508 27/02/96 TO Duncraig 336 - 13558 Autumn0584 03/03/96 RR Noranda 341 - 15326 Autumn




Appendix 3 Tagged black bream recapture information (continued)

Tag no. Date Recapture Suburb Days Increase Distance Seasonof status of at in length from release

capture fisher liberty (mm) site (m)

0172 09/03/96 FT Girraween 347 60 0 Autumn0629 11/03/96 FT 349 56 12271 Autumn0223 21/03/96 FT Duncraig 359 58 17448 Autumn0185 05/04/96 RR Herne Hill 374 - 25451 Autumn0571 05/04/96 RR Herne Hill 374 - 25451 Autumn0171 06/04/96 FT Cloverdale 375 53 255 Autumn0744 09/04/96 FT Eden Hill 378 70 17448 Autumn0334 13/04/96 TO Forrestfield 382 - 1676 Autumn0687 15/04/96 TO Hazelmere 384 - 5655 Autumn0188 19/04/96 TO Kingsley 388 - 5035 Autumn0488 21/04/96 TO Guildford 390 - 5035 Autumn0200 25/04/96 RR Gosnells 394 - 14500 Autumn

0479 06/05/96 RR Morley 415 - 0 Winter0286 12/05/96 FT Kingsley 411 73 5035 Winter0479 16/05/96 FT Belmont 405 60 -757 Winter0560 16/05/96 FT Belmont 415 75 0 Winter0279 19/05/96 FT Kingsley 418 92 5035 Winter0422 22/05/96 TO Balcatta 421 - 12271 Winter0400 25/05/96 RR Dianella 424 - 255 Winter0260 01/06/96 TO Maida Vale 431 - 255 Winter0592 11/06/96 RR Morley 441 - 2400 Winter0051 15/07/96 FT Girraween 475 - 5655 Winter

0358 07/10/96 TO Wembley 559 - -21303 Spring0467 09/10/96 TO High Wycombe 561 - -5953 Spring0604 13/10/96 TO Bassendean 565 - -1496 Spring0238 17/10/96 FT Northbridge 569 - -21303 Spring

0196 03/01/97 TO Lynwood 647 - -7532 Summer0322 06/02/97 TO Stratton 681 - 16050 Autumn0668 09/02/97 TO Bayswater 684 - -42964 Autumn0028 17/02/97 FT Swan View 692 0 649 Autumn0629 11/03/97 FT 714 83 12271 Autumn0007 16/03/97 RR Balcatta 719 - 5655 Autumn0654 30/03/97 TO Hazelmere 733 - 11131 Autumn0596 25/04/97 FT Bedford 759 123 3670 Autumn

0513 21/08/97 FT Ferndale 877 - -36666 Spring0141 26/10/97 TO Clarkson 943 - -12225 Spring0089 28/10/97 TO Ballajurra 945 - -14128 Spring

317.58 2171.515464

Recapture Status: TO - Tag Only returnFT - Fish and Tag returnRR - Re-Release

Blanks indicate insufficient information returned from fishers

Fish. Res. R

ep. Fish. West. A

ust.22

2000,124,1-23

Ap

pen

dix 4

Recap

tured

tagg

ed b

lack bream

bio

log

ical info

rmatio

nTag no. Days Age Release Recapture Release Recapture Sex Gonad Gonad Gut Prey No. of Comments

at (months) fork length fork length weight weight stage weight fullness item/s preyliberty (mm.) (mm) (gm) (gm) (gm) (0 = empty in gut items

10 = full)

722 34 15.1 165 167 125 139 H 3 0.24 0 - - empty gut434 60 16.0 150 163 73 87 F 2 0.42 8 #1 - prawn - most likely bait used157 36 15.2 155 164 96 114 M 2 0.28 1 #1 - prawn - most likely bait used538 36 15.2 166 175 112 140 M 2 0.30 0 - - empty gut74 69 16.3 157 165 97 87 F 2 0.18 7 #1 & 1 prawn - most likely bait used

#2 -648 80 16.6 168 174 115 121 M 2 0.26 0 - - empty gut482 6 14.2 179 188 136 152 F 3 1.04 5 #2 20 prey in intestine only696 7 14.2 160 160 91 91 M 2 0.58 1 #3 2 prey in intestine only529 16 14.5 182 182 125 134 F 2 0.49 0 - - empty gut18 9 14.3 169 172 143 140 M 2 0.20 2 #2 & 2 prey in intestine only

#4 - #4 - intestine also15 9 14.3 155 NA 97 NA NA NA NA NA - - no head, guts or gonads20 8 14.3 170 170 124 129 F 2 0.40 10 #1 1 prawn - most likely bait used481 NA - 164 165 117 117 M 2 0.19 8 #1 1 prawn - most likely bait used266 192 20.3 159 172 93 114 F 2 0.28 6 #4 6 #4 - intestine also236 145 18.8 143 155 74 91 M 2 0.11 2 #9 5 #9 & #2 in intestine also181 254 22.3 151 196 81 166 ? NA NA 5 #1, 1 #2, Crab and sand (#6) in intestine also

#4 & -#2 3

594 231 21.6 188 213 168 NA NA NA NA NA - - no head, guts or gonads- - distinct Moore River fish shape

586 NA - 152 200 90 205 F 3 1.46 10 #2 50 prey in intestine only587 NA - 152 200 90 205 F 3 1.46 10 #6 - distinct Moore River fish shape140 NA - 135 142 68 81 M 1 0.05 NA - - distinct Moore River fish shape106 288 23.5 167 220 118 235 NA NA NA 0 - - large vol. of #2 in intestine588 266 22.7 172 205 148 255 F 3 2.22 5 #1, - moderate vol #2 in intestine

#4 & -#8 2

165 144 18.7 170 184 121 150 M 5 1.89 0 - - #2 in intestine457 NA - 150 156 81 92 M 2 0.30 0 - -104 270 22.9 191 236 162 324 F 4 2.63 8 #7 1 #7 most likely bait used, intestine empty184 287 23.4 165 222 111 282 M 2 0.20 9 #1 - large vol. of #2 in intestine

#2 10 pink hue to scales684 287 23.4 175 232 135 NA NA NA NA NA - - no guts or gonads

- - pink hue to scales300 269 22.8 161 206 96 213 F 3 1.50 10 #2 & 5 #2 in intestine

#7 1 #7 most likely bait used291 NA - 180 191 137 157 M 4/5 1.76 0 - - some #2 and sand (#6) in intestine286 NA - 180 253 142 NA F 4 4.40 2 #1 - prawn - most likely bait used279 NA - 142 234 59 NA M 3 0.56 5 #1 - prawn - most likely bait used280 NA - 142 234 59 NA M 4 0.57 6 - - some #1 and #2 in intestine560 415 27.6 185 235 150 307 F 3 1.73 0 - - #2 in intestine479 415 27.6 150 210 90 232 F 3 2.77 0 - - #2 in intestine172 347 25.4 148 208 85 NA NA NA NA NA - - no guts or gonads 223 359 25.8 170 225 121 276 F 3 1.57 0 - - #2 in intestine744 378 26.4 165 235 97 306 F 3 2.45 10 #1 - prawn - most likely bait used629 349 25.5 197 253 187 369 M 3 0.84 10 #1 1171 375 26.3 173 226 141 299 F 4 3.00 0 - -

Prey item

key#1 =

crustacean body parts#2 =

Sw

an River m

ussel, Xenostrobus

sp.#3 =

small w

hite mussel

#4 = filam

entous algae, possible indirect ingestion#6 =

sand#7 =

polychaete, Sw

an River bloodw

orm#8 =

crustacean, amphipods ~

5 mm

#9 = sm

all brown bivalve, A

rthritica semen

22Fish. R

es. Rep. Fish. W

est. Aust.

2000,124,1-23



Appendix 5 Tagged black bream vs wild stock black bream growthcomparison

Tag no. Days Release Recapture fork Predicted fork Release Recapture Sex LN recapture FL/ at fork length length (mm) of length(mm) based weight weight predicted FL

liberty (mm) tagged fish on Potter et al., 1996 (gm) (gm)

Males 696 7 160 160 140.5 91 91 M 0.12985402318 9 169 172 141.0 143 140 M 0.198880424

157 36 155 164 147.2 96 114 M 0.108313014538 36 166 175 147.2 112 140 M 0.17323256648 80 168 174 157.0 115 121 M 0.103093265165 144 170 184 170.6 121 150 M 0.075735296236 145 143 155 170.8 74 91 M -0.096989537184 287 165 222 198.6 111 282 M 0.111625415629 349 197 253 209.7 187 369 M 0.187731463140 NA 135 142 68 81 M457 NA 150 156 81 92 M481 NA 164 165 117 117 M291 NA 180 191 137 157 M279 NA 142 234 59 NA M280 NA 142 234 59 NA M

Sample-no: 9 t-test: 3.741901 Mean: 0.110163992 DoF: 8 Variance: 0.007800767 t-signif: [email protected]

Tag no. Days Release Recapture fork Predicted fork Release Recapture Sex LN recapture FL/ at fork length length (mm) of length(mm) based weight weight predicted FL

liberty (mm) tagged fish on Potter et al., 1996 (gm) (gm)

Females 482 6 179 188 141.7 136 152 F 0.28258299520 8 170 170 142.2 124 129 F 0.178583209

529 16 182 182 144.1 125 134 F 0.233530321434 60 150 163 154.3 73 87 F 0.05470168874 69 157 165 156.4 97 87 F 0.053711142

266 192 159 172 182.9 93 114 F -0.061701531588 266 172 205 197.7 148 255 F 0.036113159300 269 161 206 198.3 96 213 F 0.038044562104 270 191 236 198.5 162 324 F 0.173025396223 359 170 225 215.1 121 276 F 0.044923016171 375 173 226 218.0 141 299 F 0.036131624744 378 165 235 218.5 97 306 F 0.072740106479 415 150 210 225.0 90 232 F -0.068916816560 415 185 235 225.0 150 307 F 0.043561167586 NA 152 200 90 205 F587 NA 152 200 90 205 F286 NA 180 253 142 NA F

Sample-No: 14 t-test: 2.931847 Mean: 0.07978786 DoF: 13 Variance: 0.010368574 t-signif: [email protected]

Documents

The evaluation of a recreational fishing stock enhancement ... · Swan River black bream have been maintained as broodstock at FMC since 1990. Broodstock have been maintained in seawater