Confirmed records of the endangered Trout Cod 'Maccullochella macquariensis' from the Murray River at Gunbower Island, Victoria

2012·1.2 MB·English

NaturalistNotes
Confirmed records ofthe endangered Trout Cod
Maccullochella macquariensis from the
Murray River at Gunbower Island, Victoria
Introduction This notepresentsinformation indicatingthe
The historical range of Trout Cod Maccullo- contemporarydistribution oftheMurrayRiver
chella macquariensis (Cuvier, 1829) is thought Trout Cod nowextends inthe MurrayRiverat
to have included much ofthe southern Mur- least to Cohuna. This extension may raise im-
ray-DarlingBasin(Lintermans2007;Trueman plications forfutureTrout Cod management.
2007). Severe reductions in both abundance ChronologyofTroutCodrangeextensionin
and distribution have led to the conservation theMurrayRiver
status of the species being listed as ‘Endan- In April 2009, the authors angled fourjuvenile
gered’ (EnvironmentProtectionandBiodiversity TroutCod(180-200mmtotallength)fromthe
Conservation Act 1999; Flora andFauna Guar- MurrayRivernearWhistlerTrackonGunbow-
anteeAct1988).Bythe 1980sTroutCodwasre- er Island near Cohuna, Victoria. More Trout
strictedtoonlyone,viable,naturallyoccurring Cod wereangledbytheauthorsfromthesame
population, located in the Murray River be- area in April 2010. These confirmed captures
tween YarrawongaandTocumwal (Berra 1974; indicateTroutCodarenowpresentintheMur-
Cadwallader et al. 1984; Ingram et al 1990). rayRiverintheGunbowerIslandarea.
ThepresentdistributionofthisTroutCodpop-
Recreational anglershavealsoreportedTrout
ulation is now reported to have increased and Cod from the area and these unconfirmed
includes the Murray River (and anabranches)
reports appear to be increasing. Anglers have
from Yarrawonga to around Barmah (TCRT reported captures at Gunbower Island to the
2008; Lintermans 2007) (Fig. 1). localCohunatacklestoreandonanglerinternet
Fig. 1. Distribution oftheTrout Codpopulation inthe MurrayRiver, south-east Australia. Bold
line indicates published Trout Cod distribution in the Murray River as reported in Lintermans
(2007);hashedlineindicatesthecontemporaryrangeextensionpresentedinthisstudy.
152 TheVictorianNaturalist
—
NaturalistNotes
forums (Fishnet and Fishvictoria). Additional the source ofthe fish and whether the fish are
anecdotal reports from anglers familiar with wild or derived from hatchery stockings. We
thespecieshave alsobeen received concerning argue that the Trout Cod in the Murray River
one fish near Murrabit in 2007, two fish from nearGunbower Islandare mostlikelytobethe
Swan Hill in 2007 andonefish near Tooleybuc resultofrangeextensioninthewildpopulation
in2008. ratherthan migration from hatcheryproduced
Indication ofan extension in the contempo- stockedfish.
rary distribution of the Murray River Trout Fishproductiontechniquesforarange ofna-
—
Cod population has been building for some tivefreshwaterspecies includingTroutCod
NSW
time. Prior to 2007, isolated reports from havebeendevelopedandrefinedbyboth
downstream of the Tocumwal area were oc- and Victorian fisheries agencies to the stage
casionally received. For example, an uncon- where they are now routine (Ingram et al
firmed Trout Cod was taken by a commercial 1999a;Ingrametal 1999b;Ingrametal 1992).
fisherman near Barmah in 1983. Buttheinitial This has allowed restocking programs to be
extension in the contemporary distribution of undertaken in an attemptto re-establishviable
the Murray River population was published Trout Cod populations in the Murray-Darling
only in 1993, when a single fish was collected Basin (Ingram et al 2008). Stocking activities
fromananabranch oftheMurrayRiverin Bar- havereintroducednearlyonemillionTroutCod
mah Forest (McKinnon 1993). This was fol- intoeightrivercatchmentsacrosstheMurray-
lowed shortly afterwards by anecdotal angler DarlingBasin (Ingrametal 2008). Evidenceof
reports of juveniles being taken in the area. natural recruitment from the stocked fish has
By about 2005, confirmed adult and juvenile been confirmed in four rivers and is suspected
Trout Codwere regularly sampled in the Mur- in another three rivers (Ingram et al 2008).
rayRiver near Barmah (Victorian Department Despite the limited success ofthe Trout Cod
of Primary Industries unpubl. data) and the breeding and stocking programs, the stocking
collection ofTrout Cod larvae by King et al. sites are all a considerable distance from Gun-
(2009) indicates that Trout Cod breeding was bower Island, and such activities are therefore
occurring in the Barmah-Millewa area. Un- not considered to be implicated in the exten-
confirmed reports ofTrout Cod captures be- sion of the contemporary distribution of the
tween Barmah and Echucawere received from Murray River Trout Cod population presented
recreational angler creel surveys conducted by inthisreport.
the Victorian Department of Primary Indus- There is evidence that some stocked Trout
triesinlate2008 (Brown2009).Fish movement Cod do movefrom their original stockingsite,
throughtheTorrumbarryWeirfishwayismon- but as adult Trout Cod have small home rang-
—
itored by Goulburn Murray staffand the weir es a few hundred metres (Lintermans 2007)
keepers recall seeing aWt least one Trout Cod in —and the closestTroutCodstockinglocations
thefishway(Terrence Holt,SeniorReservoir are hundreds ofkilometres away in the Mur-
Controller, Torrumbarry Weir, pers. comm., rumbidgee, Ovens and Goulburn Rivers, mi-
3 October2009). gration from these areas is not considered as a
likelyexplanationofTroutCodatCohuna.
Discussion
Thecapturesofconfirmed TroutCod fromthe TrTohuet CMoudrraurmobuinddgNeaerrRainvdeerraisansdtoNcSkeWd Fwiisthh-
Murray River near Cohuna confirm an exten-
eries report the current downstream extent of
sion in the contemporary distribution of the Trout Cod as Leeton Ski Club (Dean Gilligan,
Trout Cod in the Murray River population.
This extension is a positive development in pbeerso.vecrom4m0.0).kmLeeutposntrSekaimColfubthiesMeustrirmaayteRdivt-o
Trout Cod conservation and should encourage
er junction near Tooleybuc; therefore, Mur-
conservation efforts as applied to the Murray
rumbidgee River Trout Cod stockings are
Riverpopulation.
AkeyquestionregardingthepresenceofTrout unlikely to explain the captures at Gunbower
Island.
Cod intheMurrayRiveratGunbower Island is
Vol 129 (1) 2012 153
NaturalistNotes
The Ovens RiverhasbeenstockedwithTrout to the Newell Highway Bridge at Tocumwal.
Codandwasformerlyconsideredtheupstream The regulations mayrequire review as the dis-
limit of the contemporary range in the Mur- tribution ofTroutCod alongthe MurrayRiver
ray River (Lintermans 2007). Given that the extendswellbeyondthisprotectedarea.
Ovens River enters Lake Mulwala upstream A major problem with Trout Cod conser-
of Yarrawonga Weir, it is highly unlikely that vation is the difficulty of distinguishing the
stocked fish have travelled downstream from species from the closely related Murray Cod
their stocking site, through Lake Mulwala, the Maccullochella peelii. Anglers may easily misi-
Yarrawonga and Torrumbarryweirs,to the ex- dentifyTroutCodasMurrayCodbecausethey
istingTroutCod populationbelowYarrawonga maynotbeawareoftheir presence in the mid-
atGunbower Island. Murray River and therefore do not correctly
Trout Cod have been stocked into the Goul- identifythespecies. Educationalprogramsmay
burn RiverupstreamofSheppartonandthereis nowbe required to inform recreational fishers
evidenceofcontinuedoccupationandbreeding that Trout Cod distribution has extended in
ofstocked fish in theriver (Kosteretal. 2004). the Murray River. A publicity campaign high-
This is the closest stocked population to Gun- lighting the extended distribution and how to
bower Island. It is feasible that some ofthese distinguish Trout Cod from Murray Cod may
fish may have travelled downstream to the assistinfisheriescomplianceissuesandinpro-
Murray River and then through Torrumbarry tecting the endangered Trout Cod in their ex-
Weir to Gunbower Island. It is possible that pandingdistribution.
some of the Goulburn River fish could have A specific objective of the current national
moved downstream intotheMurrayRiver and Trout Cod recoveryplan isto facilitatecontin-
be responsible for some ofthe Trout Cod cap- ued sustainabilityofTroutCodpopulations. A
tures reported by anglers from the river in the specific performance criterion for the objec-
Echucaarea. tive isthattheareaofoccupancyofthenatural
Given thechronologyofreportsofTroutCod MurrayRiverpopulationisstableorincreasing
numbers increasing downstream in the Mur- (TCRT 2008). Evidence ofan extension in the
rayRiverfromTocumwal,weconsiderthatitis distribution ofthe population wouldmeet this
morelikelythattheTrout Codin theGunbow- performance criterion and indicate that con-
er area represent an extension ofthe contem- servation efforts for the recovery ofTrout Cod
porary distribution ofthe Murray River Trout arebeingeffective.
Codpopulation—through recruitment andex-
Acknowledgements
pansion in thenaturalpopulation—ratherthan
The authors would like to thank Scott Douglas for
immigration of stocked Trout Cod. However, assisting with angling the Trout Cod, and Brett In-
the fish stocked in the Goulburn River cannot gram, DaveMolloy,Jon Presserandtwoanonymous
be discounted as the source. Regardless ofthe referees tor their helpful comments on the manu-
source,TroutCodare nowpresentintheMur- script.
rayRiveratGunbowerIsland. References
We conclude that the Trout Cod distribu- BerraTM(1974)Thetroutcod,Maccullochellamacquarien-
tion in the Murray River has extended past sCios,nsaerrvaarteiofnre6s,h5w3at-e5r6.fish ofeastern Australia. Biological
the previously-published limits in Lintermans Brown P (2009) Sustainability ofrecreationalfisheriesfor
(2007)andcurrentlyextendsdownstreamfrom Murraycod:CreelSurveysontheMurrayGoulburn, Ovens
Yarrawonga to at least the Murray River con- aPrnodgLroadmdo—nRreisveerasr2ch00r6e-p2o0rt0.8.FiRsheecrrieeastiRoenvaelnFuieshAilnlgocGartainotn
tiguouswithGunbowerIsland.Anextensionin Committee,Melbourne.
TroutCodpopulationdistribution in the Mur- CatdrwiablultiaodnesraPnLdatrnadnsGlooocalteiyonGsJof(1M9u8r4r)aPyasctodanMdacpcruelsleoncthedlilsa-
rayRiverhasimplications forthemanagement peeliiandTroutCodM.macquariensis(Pisces:Percichthy-
ofthespecies,both in termsofregulations and 9id6ae3)3i-n43Vi.ctoria.ProceedingsoftheRoyalSocietyofVictoria
whTehreecpuerorpelneteNxpSecWt tFoisfhienrdietsherescpreceiaetsi.onal an- InSgJra,anmdBSAa,ngBearrAloCw(C1G9,90)ButrhcrhemaoterneedJJ,naGtoiovleefyreGsJh,waRtoewrlfaisnhd-
esinAustralia-somecasehistories.JournalofFishBiology
gling regulations include a seasonal angling 37(SupplementA),175-182.
closuredownstreamfromtheYarrawongaWeir
154 TheVictorianNaturalist
NaturalistNotes
Ingram BA, GooleyGJ and De Silva SS (1999a) Develop- TroutCodRecoveryTeam(TCRT)(2008)NationalRecovery
ments in the aquaculture of Australian percichthyids, PlanfortheTroutCodMaccullochellamacquariensis.(De-
MraacmcuunldloichFealrlmainspgp.WoIrnkPsrhoocpee(dBirnigbsieofIstlhaend,Aus1t2r-a1l3iaAnugBuasr-t TrpuaermtamnenWtTofS(u2s0t0a7in)abSiolimtey:rMeceollbleocutrionnes)ofnativefish in the
m19a9r9y),Inpdpu.st5r4i-e5s9). Ed MJ Wingfield. (Department ofPri- MCuordraMyac-cDualrlloicnhgelslyastemmacqwuiatrhisepnesciisa.lrSeufemrmenacreyto&theSoTurrocuet
IngramBA,GooleyGJ,DeSilvaSSandLovricD(1999b)De- Material from the Draft Publication ‘Bluenose: The Lost
velopmentofintensiveculturemethodsforAustralianper- WorldoftheTroutcod’PreparedasanInterimReportfor
cichthyids,Maccullochellaspp.InTheAnnualInternational NativeFishAustralia(Victoria)Incorporated.
ConferenceandExposition ofthe WorldAquacultureSoci-
Inegtyr.aBmoBokAoafnAdbstRriamctmser(2M6AApri(l19-922)MIanydu1c9e9d9).br(eSeyddinnegy)and
larvalrearingoftheendangeredAustralianfreshwaterfish
Troutcod,Maccullochellamacquariensis(Cuvier)(Percich-
thyidae).AquacultureandFisheriesManagement24,7-17.
IngramBAandThurstanS(2008)Re-introductionofTrout
Cod into the Murray-Darling River Basin, Australia. In
GlobalRe-introduction Perspectives. Re-introduction case-
studiesfrom around theglobe, pp. 37-41. Ed PS Soorae. John Douglas
(UIAUEC)N/SSCRe-introductionSpecialistGroup:AbuDhabi, FisheriesManagementBranch,
KifnlgowAJe,nhTaonnckeisnnaZtiavendfisMhashpoanwenyingJ a(2n0d09r)ecErunivtimreonntmeinnttahle FisheriesVic4t6orAiia,tkDeenpSatrrteemtenAtleoxfanPdrriam,arViycItnodruisatr3i7e1s4,
MurrayRiver,Australia.Riverresearchandapplications25,
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KosterW,CrookDandFairbrotherP(2004)SurveysofFish FisheriesResearchBranch,
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andWoodenI(2005)Thestatus,threatsandmanagement POBox494
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sin. Statement, recommendations and supporting papers
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McKinnonLI(1993)Asignificantrecordoftheendangered
Troutcod,Maccullochella macquariensis (Pisces: Percich-
thyidae) madeduringfish surveys ofthe Barmah Forest,
Victoria.TheVictorianNaturalist110,186-190.
Onehundredandten yearsago
NATURAL HISTORYNOTE
Thehon.secretaryreadanextractfromaletterfromMr. M‘Bain,ofPointLonsdale,toMr. S.A.LeSouef
withreferencetothespawningoftheMurrayCod,Oligorusmacquariensis,inwhichthewritergaveitas
hisexperience thatthefishspawnsaboutNovember,whentheriver,owingtothemeltingofthesnow,is
atitshighest,andspreadsovertheflatsalongitsbanks,sometimesformiles.Thoughhehadnotseenthe
ovahebelievesthefishspawninhollowburntlogsontheflats,wherethewateriswarm,havingfrequently
disturbedthefish in suchplaces, andafterwardsseenyoungfrynot morethanaquarterofaninchlong
swimmingabout intheholes. Directlythewatercommencestorecedetheyoungfrydepartandarenext
found in the mainstreams inplaceswherethereareeddies, and thebanksfringedwith weeds andlong,
thingrass;heretheyareaboutaninchlong,andifnotdisturbedwillremaininthelocalityuntilthenext
season,whentheywillbeabout4inchesinlength.
From TheVictorianNaturalistXIX, p.83,October9, 1902
Vol 129 (1) 2012 155