Nassau Grouper Guide for Schools
Transcript of Nassau Grouper Guide for Schools
Nassau Grouper an Iconic Bahamian Species
The
GuIde for BahamIan SchoolS
• Classification
• DistinguishingFeatures
• LifeCycle,Adaptations
• Importance
• Threats,ConservationandManagement
• ClassroomActivities
APublicationofThe
Bahamas Reef environment educational Foundationwww.breef.org ForEducationalUseOnly
Nassaugrouperarevulnerabletooverfishingbecauseduringthewintermonthstheyformlargegroupscalledspawningaggregationsor‘schools’inordertoreproduce.Theseaggregationsformatpredictabletimesandlocationsandarethereforeaneasytargetforfishers.Catchingthefishatthistimethreatensthesurvivalofthespeciesandthusthelivelihoodofthepeoplewhodependonthem.Theaggregationsaretheonlyopportunitiesfortheseiconicfishtoreproduce.
TohelpsustaintheBahamianNassaugrouperfishery,protectionofNassaugrouperspawningaggregationsbeganin1998withseasonalclosuresduringthewintermonths.DuringtheclosedseasonthecaptureorsaleofNassaugrouperisprohibited.ThisconservationmeasurewillhelptoensurethatthereisaplentifulsupplyofthisfishfortheenjoymentoffuturegenerationsofBahamians.
ThisbookletwasdevelopedbyBREEFtosupportthelearneroutcomesoftheScienceandSocialSciencecurriculainTheBahamas.TheinformationcanbeutilizedtoteachEnvironmentalBiologyunitssuchasBiodiversity,InterdependencebetweenSpeciesandtheEnvironment,EndangeredSpecies,ProtectedAreas,ConservationandEnvironmentalStewardshipand,FisheriesManagement.Discussionquestionsdenotedby havebeenincludedthroughout.
FormoreinformationaboutNassaugrouperandmarineecologyresourcesvisitourwebsiteatwww.breef.org.Bookclassroompresentationsorcoastalfieldtrips,[email protected].
Welookforwardtoyourfeedbacksothatwecanbetterserveyourmarineeducationneedsandpromoteenvironmentalstewardshiptoall.
The Nassau grouper is the most important commercial fin fish species in the Bahamas. The species, however, has been overfished throughout the region and is considered an endangered species throughout its range. The Bahamas is considered to be one of the few regions in which fish populations are considered to be ‘relatively’ healthy.
Note to Teachers
TheBahamasReefEnvironmentEducationalFoundation(BREEF)isaBahamiannon-profit
foundationestablishedin1993.OurmissionistopromotetheconservationoftheBahamianmarineenvironmentthatsustainsourwayoflife.BREEFinformsthepublicaboutourmarineenvironmentandthethreatstoouroceansandcoralreefs,motivatingpeopletogetinvolvedwithprotectingourcriticalresources.
BREEFiscommittedtoeducatingpeopleaboutthemarineenvironmentandtherolethatitplaysinourtourismandfishingindustries,andinprovidingfood,recreationandshorelineprotectionforusall.Thisimportantlearningtool,developedbyBREEFwithfundingfromtheLyfordCayFoundation,isdesignedforuseinBahamianclassrooms.Itwillhelptoprovideenriching,engagingclassroomexperiencesforsciencestudentsthroughoutTheBahamas.
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TheNassaugrouperisanimportantmarinespeciesnativetotheBahamasandtheCaribbeanregion.ConcernsaboutthestatusofthisnaturalresourceandtheimpactofitsdeclineonthecultureandsocioeconomicenvironmentoftheBahamashaveledtotheimplementationofconservationandfisherymanagementstrategiesdesignedtopreventcollapseofthisimportantfishery.
ManyBahamiansrelyongrouperforemployment,togeneraterevenueforthediveandtourismindustriesandasanimportantfoodsource.Itistherefore,essentialthatadequatemeasuresareputinplaceandenforcedforeffectivemanagementofthisspecies.
Introduction
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nassau Grouper - Classification/TaxonomyTheClassificationsystemisdesignedtodescribeandgrouplivingthingsmakingthemeasiertoappreciateandstudy.Therearesixbasiclevelsintheclassificationsystem.Theyare:
Kingdom Phylum Class Order Family Genus Species
Organismsaregroupedaccordingtotheircharacteristics.Thelargestgroupingisthekingdom.Organismsinthesamekingdomsharethesomebasicfeaturesbutcanbeverydifferentinappearance.
Asonemovesthroughtheclassificationlevels,fromkingdomtospecies,theorganismsineachgrouphavemorefeaturesincommon.Thesmallestgroupiscalledthespecies.Organismsofthesamespeciesaresoalikethattheyareabletosuccessfullyreproduceandproducefertileoffspring.
TheNassaugroupercanbeclassifiedasfollows:
Kingdom Animal –multicellularorganismsthatingesttheirfoodPhylum Chordata (Vertebrates)–animalswithbackbonesClass Actinopterygii–fishwithfinsthatconsistofawebofskinsupportedbybonyspinesOrder Perciformes–dorsalfinsdividedintotwopartsi.e.spinyatthefrontandsoftat thebackFamily Serranidae–allgroupersandseabassesGenus Epinephelus Species striatus
Thecommonnameofanorganismcanvaryfromplacetoplace.Thereforetoavoidconfusion,eachorganismisgivenaninternationallyrecognizedscientificname.Anorganism’sscientificnameisderivedfromitsgenusandspecies.ThisiscalledtheBinomialSystemofNomenclaturei.e.namingspecies
Binomial = Bi (Two) + Nom (Names)
Common Name Scientific Name
Nassaugrouper Epinephelus striatusQueenConch Strombus gigasSpinyLobster Panulirus argus
InascientificnamethegenusbeginswithaCAPITALLETTERandthespecieswithalowercaseletter.Thesearetheneitherunderlinedorwritteninitalics.
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Importance of the nassau GrouperTheNassaugrouperisanimportantreefinhabitantthroughouttheCaribbeanregion.
•Thehealthofthereefisdependentonthedelicatebalancebetweencorals,algae(seaweed),herbivores,carnivoresanddetritivores.Asahigherlevelpredator,Nassaugrouperhelpcontrolthepopulationofotherreeforganismshelpingtomaintaintheecologicalbalance.
•Itisanimportantfoodfish,andisthereforeanimportantpartof Bahamianculture.
‘Boil fish’ is traditionally made with Nassau grouper. How can the Bahamian public continue to enjoy this dish during the closed season?Boil fish can be made with other fish species such as red snapper and hog fish. Bahamians can also be encouraged to try lionfish as an alternative. Eating lionfish would also help to reduce the numbers of this harmful invasive species.
•Thefishingindustrycontributesapproximately$85-90Mannuallytotheeconomy,withsalesofNassaugroupercontributingapprox$1.5M.Nassaugrouperisfishedcommerciallyandrecreationallybyhandline,fishpots(traps),andhawaiianslingandspear.
Fishers need to be able to continue to make a livelihood during closed seasons. What can we do to support them? Purchase other species of fish during the closed season such as snappers. Support the establishment and respect the boundaries of Marine Protected Areas (MPAs). Create other job opportunities.
•DiversandsnorkelersfromaroundtheworldvisitTheBahamas.TheopportunitytoencounterendangeredspecieslikeNassaugrouper,sharksandseaturtlesinthewildaddsvaluetoourtourismproduct.
•Studieshaveindicatedthatsomegrouperspeciesarepredatorsofthelionfish.Lionfishareavenomousinvasivemarinespecieswithfewnaturalpredators.Theycompetewithnativefishlikesnappersandgroupersforfood,threateningtheirsurvival.Maintaininghealthygrouperpopulationsmayhelptocontrollionfishpopulations.
Diet
Juvenile Nassau grouper: small crustaceans, small fish
Adult Nassau grouper:shrimp, crabs, octopus, a variety of reef fish
An invasive species is a non-native (alien) species that can cause harm to the economy, the environment or to human health.
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Distinguishing Features of the Nassau Grouper
TherearemanydifferenttypesofgrouperinBahamianwaters:Theseinclude:Tigergrouper,Blackgrouper,Rockhind,Goliathgrouper(Jewfish),Yellowfingrouper,Yellowmouthgrouper,andConeys,eachwithspecificdistinguishingfeatures.Althoughgroupersaresimilarinappearance,theNassaugroupercanbeeasilyrecognizedby:
Grouperscanchangecolortoblendinwiththeirhabitat.Infact,Nassaugrouperexhibitfourcolorpatternswhilebreeding.howevertheycanalwaysbedistinguishedfromothergroupersbythedarksaddle-shapedmarkingonthebaseofthetail.ForidentificationpurposesallothergroupercaughtduringtheNassaugrouperclosedseasonmustbelandedwiththeheadonandtheskinintact.
The government has declared that all grouper caught during the closed season must have its head and tail on and skin intact. Why is this rule necessary?Since other grouper species can be caught during the Nassau grouper closed season. Nassau grouper are easily distinguished by the black saddle shaped marking on the base of the tail.
Diagonal marking (band) through the eyes
Five olive brown vertical markings (bars) on a light body
Y-shaped marking on the front of the face between the eyes
Dark saddle shaped marking on the base of the tail
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Despiteitsname,theNassaugrouperhasbeenhistoricallyfoundthroughoutthewesternAtlanticOcean,GulfofMexicoandtheCaribbeanSea,includingBermuda,FloridaandTheBahamas.howevertodaymanyofthesepopulationsareindecline.
Habitat & Life CycleNassaugrouperoccupyavarietyofhabitatsduringtheirlifecycle.Althoughadultgrouperareusuallysolitaryanimals,duringthefullmoonsofNovembertoMarchtheymigrateoverlongdistances,groupingtogetherinlargenumberstobreed.Aschoolofbreedingfishiscalledaspawningaggregation.historicallyaggregationshadtensofthousandsoffish,buttodaythesenumbershavedwindledsignificantly.
Otherfish,includingsnappers(muttonfish,lanesnappers,etc.)andotherspeciesofgrouper,andbonefishalsoaggregatetospawn.Theysometimesusethesamespawningsites,butmaydosoatdifferenttimesofyear.
Spawning BehaviourNassaugrouperchangecolorwhentheybreed.Duringtheday,theymayexhibittheirnormalcoloration.however,atdusk,justbeforespawning,fourdistinctcolorphasesarevisibleinaspawningaggregation.Theseare:
•Normal–typicalcolorationofaNassaugrouper.•Bicolor –occursinbothmalesandfemalesduringthelateafternoon.Thesehaveadarkbackandalight-colouredbelly.•White belly-femalesinthenormalcolorphasebutwithwhiteabdomensswollenwithova(eggs).•Dark –seenincourtingandspawningfish,theentirebodyisdark.Theseareprobablyfemalesthatarereadytospawn.
Spawningoccursaroundsunset.Atthistimethefishperformcourtshiprituals,releasingspermandeggsinthewater.Eggsarefertilizedexternally(inthewater)andhatchwithin23-40hours.Thelarvaefloatinthewatercolumnfor35-70days,afterwhichtheysettleintonurseryareas,suchasmangrovecreeksandseagrassbeds.Afterayear,thejuvenilesgenerallymovetoshallowreefswheretheyremainforuptofouryearswhentheyusuallymovetodeeperreefs.MostNassaugrouperaresexuallymaturebythetimetheyaresevenyearsold.
Source: Woods Hole Oceanographic Institution website: http://www.whoi.edu Illustration by Jack Cook/WHOI Graphic Services
Geographical distribution
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How does the reproductive behavior of Nassau grouper make the species vulnerable to overfishing?
•Nassaugrouperareslowtomature,theystartatfourtofiveyears(3.8-4lbs).Approximately75%ofthepopulationissexuallymatureatsevenpounds.Theyalsoreproduceseasonally,i.e.onlyduringthewintermonths.Thesefactorsresultinfewoffspringandpopulationsthatcanbeeasilyoverfished.Incontrast,lionfisharesexuallymatureatoneyearandreproduceyearround.
•Nassaugroupergatherinlargenumbers(historically1000s,currently100s)tospawnatpredictabletimesandlocationsmakingthemaneasytargetforfishers.
•Fishingonaspawningaggregationresultsintheharvestofbreeding fishthatmaynothaveyethadachancetoreleasetheirgametes(spermandeggs).
•Thefishtravellongdistances,over100miles,toreachanaggregationsite.Thereforeharvestingfishatanaggregationsitedepletesnotonlylocalfishpopulationsbutalsopopulationsfarawaysincefishareunabletoreturntotheirhomereefs.
•Fishingactivityataspawningsitemaydisruptbreedingactivity.
•Currently(2014),theminimumsizelimitforharvestingNassaugrouperinTheBahamasisthreepounds(approx.17”length),yetrecentscienceindicatesthattheyarenotsexuallymaturebeforetheyweighatleastfivepounds.Asaresult,somegroupersarelegallycaughtasjuveniles,beforetheyhavehadachancetoreproduce.
Why do closed seasons correspond with the reproductive seasons of organisms?This ensures that the species is allowed to reproduce successfully, ensuring replenishment of our marine resources and safe guarding livelihoods.
Fish Spawning Aggregation (FSA)
Spawn = eggs of an aquatic animal +Aggregation = a collection or grouping (schooling)
Nassau Grouper Factoids:
• Nassau grouper start to mature at 4-5 years old (19” length). 75% of the population matures by 22”.
• Spawning sites are also called ‘grouper holes’.
• Nassau groupers may swim over 100 miles from their home reef to reach a spawning aggregation site.
• They return to their home reef after spawning.
• They may live for 20+ years.
• Nassau grouper swallow their prey whole.
• Nassau grouper have been reported to eat lionfish which have very few natural predators in this region. A healthy Nassau grouper population may help to reduce the numbers of harmful invasive species.
• Like many reef fish Nassau groupers can change sex from female to male.
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Life Cycle of the Nassau GrouperEpinephelus striatus
eggs and sperm released into water during spawningFertilized egg
23-40 hours
LarvaePlanktonic larvae
float on ocean currents for 35-50 days
early Juvenile
Stage10-12 months in mangrove creeks
& seagrass
Sub-Adult Stage
1-4 years shallow patch reefs
Adult5+ years
deeper reefs
movement to patch reefs larvae settle
onto the seafloor
eggs hatch
*migration toand from fSa
movement to deeper reefs
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fish adaptationsAdaptationsarephysicalfeatures,behavioursandphysiologicalcharacteristicsthatallowanorganismtosurviveinitsenvironment.Forexample,fishareadaptedtolifeinwater.Theyhavefinsforswimmingandgillstoextractoxygen.
TheNassaugrouperisasolitary,bottomdwelling,carnivorouspredatorthatfeedsonawidevarietyoffish,suchasgrunts,andparrotfish.Theyalsofeedoninvertebratessuchascrabs,octopus,andcrawfish.Theyareambushpredators,waitinginreefcrevicesforunsuspectingpreywhichtheyengulfwholewithstrongsuction.ANassaugroupercanswallowpreyhalfitslength.
ThephysicaladaptationsofaNassaugrouperareconsistentwiththoseofacarnivore:themuscularbodyandroundedtail,allowsthemtomaneuvereasilyandtoswimwithshortburstsofspeed.Bodystripesandtheabilitytochangecolorallowthemtocamouflagesothattheyarelessvisibletopreyandpredators.
Physical adaptationsoffishinclude:Bodyshape- the flattened shape of a ray indicates that it is a bottom dweller, while the streamlined shape of barracuda indicates that it can swim fast.
Mouthsize– a small mouth indicates an herbivorous fish (surgeonfish); a large mouth indicates a carnivore (grouper).
Toothsize/shape– carnivores often have large pointed teeth (barracuda) while herbivores have small or fused beak-like teeth (parrotfish).
Colorpattern– bright colors warn of potential danger (lionfish – venomous), whilst predators are often silvery or camouflage to conceal them from prey (barracuda).
Tailshape– a forked tail indicates a fast swimmer (marlin), whilst a tapered tail belongs to the slowest (eel).
Distinctivemarkings– spots and stripes break up the body shape to confuse predators.
Laterallines– detect vibrations/movement in water.
Behavioral adaptations canbeinheritedorlearned.Theyarestrategiesthatalloworganismstosurviveintheirenvironmentbyhelpingthemtofeed,avoidpredation,respondtoenvironmentalchangesandtoreproduce.
Examples are:
Socialbehaviours– solitary, schooling, colonial, territorial
Predationstrategy– ambush, pack hunting, trapping
Survivalstrategy– swimming speed, burrowing
Periodofactivity– nocturnal, diurnal
Locomotion– motile, sessile, migratory
Courtshipdisplay– color changes, swimming patterns
This grunt was removed whole from the Nassau grouper’s stomach
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GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species 9
Physiological adaptations aremetabolicresponsestoanorganism’senvironmentthatensureitssurvival.Examplesincludetheabilitytowithstandhypoxic(lowoxygen)conditionsortemperatureextremes,andtheproductionofvenomtocapturepreyorasadefensemechanism.Bioluminescenceoftenseenindeep-seafishcanattractmatesorattractprey.Organismsalsoutilizeavarietyofreproductivestrategiestoincreasethesurvivalofoffspring:eggguarding,livebirth,hermaphroditism,abilitytochangesex,synchronousreleaseofgametes,andproductionofvastnumbersofoffspring.
Which of the reproductive strategies mentioned do Nassau grouper employ and what is the advantage of this to the species?Synchronous release of gametes – Nassau grouper aggregate to spawn. During courtship males and females release eggs and sperm at the same time. This increases the probability that the eggs will be fertilized. Since Nassau grouper are unable to care for their young, the more offspring that they produce, the greater the chance that some of them will survive to adulthood.
The Nassau Grouper Fishery in The BahamasDuetopopulationdeclinesthroughoutitsrangetheNassaugrouperisconsideredanendangeredspecies.TheBahamasisoneofthefewplacesinwhichthisspeciesisstillharvestedonacommercialscale.TheDepartmentofMarineResourcescollectsfisherylandingsdata,andin1994startedtodistinguishbetweenlandingsofNassaugrouperandothergrouperspecies.Betweentheyearsof1994-1997,sevenhundredto1.1millionpoundsofNassaugrouperwerereportedtobelandedannually.MonthlylandingsdatashowsthatmuchoftheannualcatchwasharvestedfromspawningaggregationsduringthewintermonthsofDecembertoFebruary.
In1998sitespecificclosures(AndrosandLongIsland)wereimplementedwithcountrywideclosedseasonsbeginningin2004.FisherieslandingsforNassaugrouperfrom2004onwardthereforereflectNassaugrouperharvestedduringtheopenseason.Landingsdatashowadeclineintheamountoffishlandedonanannualbasis.Thisdeclinemaybeduetotheimplementationoftheclosedseasonsincewhatwaspreviouslythemostproductivetimeofyearforlandingsisnowclosed.Thedatamayalsoreflectchangesinfishingeffortbutraisesconcernsaboutthesustainabilityofthefishery.Currentsurveysofspawningsiteshavedocumentedpopulationdeclinesandpoachingactivity.
ArethelastremainingNassaugrouperfisheriessustainable?In2009theDepartmentMarineResourcespartneredwithscientiststoexplorethisissue.280fishermenfromthroughoutTheBahamaswereinterviewedtorecordtheirviewsonthestatusofthefisheryanditsfuture.
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TheinterviewsrevealedthatmostofthefisherswereconcernedaboutthestatusoftheNassaugrouperfishery.Theyexpressedconcernsaboutoverfishing,thecaptureofsmall-sizedfish,theuseofcompressors,poachingandthelackofmonitoringandenforcementoftheclosedseason.Accordingtothefishers,thelandingsofNassaugrouperhavebeendecliningsincethe1900’sbeforeseasonclosuresbegan.ThistrendisreflectedinthefisheriesdatawhichshowsthatalthoughtheNassaugrouperlandingshavebeendecliningsteadily,thetotalfisherieslandingshavenotbeendecliningtothesameextent.Giventhesefindings,thestudyconcludesthatTheBahamas’Nassaugrouperfisherymaybefullytoover-exploited.Thestudygivesthefollowingrecommendationsforthemanagementofsustainablefishery:continuationoftheannualclosedseason,improvedmonitoringcontrolandsurveillanceduringtheopenandclosedseasonsataminimum,alongwithprotectionofspawninggroundswithinMPAs,continueddatacollectionandassessmentofNassaugrouperpopulations.
Protection and managementIn1996andagainin2003,theNassaugrouperwasplacedontheInternationalUnionforConservationofNature(IUCN)RedListforspeciesatahighriskofglobalextinction.Thespecieshasbeenassessedasendangeredbecauseitisestimatedthatitspopulationhasdeclinedby60%inthelast30years.
Regionally,overathirdoftheNassaugrouperspawningaggregationshavedisappeared.ItisconsideredtobecommerciallyextinctinFlorida,Bermuda,PuertoRicoandtheVirginIslands.InBermuda,grouperlandingsdeclined15-foldoverasixyearperiod,andinCuba,ofthespawningaggregationsidentifiedin1884,onlyoneexiststoday.Todate,recoveryatanextinctsitehasneverbeenrecorded.InTheBahamas,thereisstrongconcernoverthestatusofourNassaugrouperpopulationsassignificantpopulationdeclineshavebeenrecordedforallstudiedaggregationswithseveralnolongeroccurringattimeswhentheyhadformedinthepast.
Nassau grouper landing by value ($) and weight (lbs.) 2002-2011 Source: The Department of Marine Resources
1,000,000
900,000
800,000
700,000
600,000
500,000
400,000
300,000
200,000
100,000
0
3,000,000
2,500,000
2,000,000
1,500,000
1,000,000
500,000
0
TOTAL NASSAU GROUPER LANDINGS: 2002 - 2011
2002200320042005200620072008200920102011
Value($)Value($)
Weight(lbs)Weight(lbs)
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ThreatsOrganismsareconstantlyfacedwiththreatsbothnaturalandhuman-inducedthataffecttheirsurvivalandabilitytoreproduce.Throughnaturalselection,theyareadaptedtocopewithnaturallyoccurringthreatstotheirsurvivalincludingdisease,predation,naturaldisastersandcompetitionbetweenspecies.however,duetoadvancesintechnologyandincreasedhumanpopulationpressure,humanshaveaddedstressorsthathaveresultedinpopulationdeclinesandextinctions.humanactionsthathaveresultedindeclinesinNassaugrouperpopulationsinclude:
Fishing on spawning aggregationsNassaugroupergatherinlargenumberstospawnatpredictabletimesandlocations.Thisbehaviourmakesthemparticularlyvulnerabletooverfishingbecause:
a.fishingonaspawningaggregationremovesfishthatmaynothavehadanopportunitytoreproduce.b.fishingonanaggregationinoneareacandepletefishpopulationsinotherareas.c.fishingactivitymaydisruptspawningbehaviour.
Fishing during the closed seasonTheclosedseasonoccursduringthewintermonthsofDecembertoFebruary,correspondingwiththemainmonthsofbreedingperiodfortheNassaugrouper.Catchingthefishatthistimeofyearreducesthenumberofsexuallymaturefishinthepopulation.
Harvest of juvenilesBahamianFisheriesRegulationsprohibittheharvestofgrouperweighinglessthanthreepounds.Catchingundersized/immaturegrouperbeforetheyaresexuallymatureandcanbreed,threatenspopulationsforthefuture.
Habitat loss Nassaugrouperinhabitmangrovecreeksasjuvenilesandcoralreefsasadults.Bothoftheseecosystemsarebeingnegativelyimpactedbyhabitatdestructionforcoastaldevelopment,e.g.dredging,pollution,climatechangeandbythepresenceofinvasivespecies.
Pollution Pollutionandrun-offofsedimentandnutrients(fertilizers,sewageetc.)fromthelanddecreaseswaterclarityandencouragethegrowthofseaweedthatpreventscoralgrowth.Coralreefs,thehabitatofadultNassaugrouper,needclearsun-litwatertothrive.
Invasive speciesInvasivespeciesarenon-nativespeciesthatcanharmtheenvironmentbyreducingnativebiodiversity.Thelionfishisathreattogrouperpopulations.Lionfisharecarnivorous,venomousfish.TheirdietissimilartothatofcommerciallyimportantfishspeciessuchastheNassaugrouperandsnappers.Lionfishthereforecompetewithgroupersforprey.
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management of the nassau Grouper FisheryInresponsetothedeclineofNassaugrouperstocks,avarietyofconservationmechanismshavebeenimplementedbothregionallyandlocally.
•Closed seasons–fishingisprohibitedorlimitedduringaspecifiedperiodthatcoincideswiththebreedingseason.InTheBahamas,theGovernmentdeclarestheclosedseasonatitsdiscretion.Unlikethecrawfishseason,theNassaugrouperclosedseasonhasnotyet(2013)beenfixedinlegislation.BREEFandotherconservationpartnerssupportthestrengtheningoflawsregardingtheclosedseasontoincludeannualfixeddatessothatfishers,restaurantsandthegeneralpubliccanmakeadequatepreparations.Untilthisoccurs,timelyclosureadvisoriesshouldbeissued.InTheBahamas,site-specific,seasonalclosuresofspawningaggregationsitesbeganwiththe1998/99breedingseasonswhichprogressedtocountry-wideseasonalclosuresin2004tomakeenforcementmorefeasible.SpecialprotectionisalsousuallygiventothehighCay,Andros,spawningaggregationsite.
What other regulations are needed to ensure that the closed season is not violated?BREEF and other NGOs advocate for the sale (by fishers, restaurants etc.) of Nassau grouper to be prohibited during the closed season. Marine Protected Areas should be established which protect known spawning sites. These sites can be effectively monitored by defense force officers, park wardens and fisheries officers.
Do you think that there should be a closed season for any other species, if so, why?Varied, opinions - based on concepts learned. Although closed seasons reduce fishing pressure, in other regions they have proven to be ineffective if they are established after populations have declined below critical levels. Another factor that must be considered is the timing of closed seasons. For example, a closed season for conch would coincide with the closed season for crawfish. If two fisheries are closed at the same time, this can negatively impact the livelihood of fishers and the economy. Other methods that may be considered for protection of marine species are: establishment of Marine Protected Areas and reducing or eliminating export of a particular marine product to reduce the demand for harvest and therefore protecting our food security.
Bahamas Country-wide closed seasons to date:
Jan 1 - 31 2004
Dec 16 2004 - Feb 16 2005
Dec 13 2005 - Feb 14 2006
Dec 1 2006 – Feb 28 2007
Dec 15 2007 - Feb 28 2008
Dec 1 2008 – Feb 28 2009
Jan 1-Feb 28 2010
Dec 1 2010 - Feb 28 -2011
Dec 1 2011 - Feb 29 -2012
Dec 1 2012 - Feb 28 -2013
Dec 1 2013 - Feb 28 2014
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•Establishment of a Bahamian network Marine Protected Areas (MPA) –theseactasreplenishmentzonesandshouldincludeallhabitatsessentialfortheNassaugrouperlifecycle–mangrovecreeks,seagrassbeds,shallowreefs,deeperreefs,andspawningaggregationsites.StudiesindicatethattheNassaugrouperpopulationisfargreaterintheExumaCaysLandandSeaPark(ECLSP)whichhasbeenano-takezone(allfishingisprohibited)since1986.Additionally,anetworkofMPAsisbeingestablishedthroughoutTheBahamastoprovidefisheryreplenishmentzones:e.g.SouthBerryIslandsMarineReserve,TheExuma(JewfishCays)MarineReserve,NoNameCayMarineReserve.ThroughtheBahamas2020Declaration,theGovernmentofTheBahamashascommittedtoeffectivelyconserveatleast20%ofthenear-shoremarineenvironmentacrosscountryby2020.
The Bahamas is expanding its network of Marine Protected Areas. How does this support our fishing industry?Effective MPAs protect fish species within their boundaries, increasing fish populations which then repopulate adjacent fishing grounds. Fish within reserves can successfully reproduce, seeding adjacent fishing areas with larvae. Marine Reserves protect critical habitat that is essential to the survival of important fishery resources such as conch, grouper and crawfish.
•Size limits–regulationslimittheharvestofjuveniles(lessthan3pounds).
•Fishing bans–Since1990therehasbeenacompletebanonthefishingofNassaugrouperinUSfederalwaters.
•Protection of specific spawning sites during the closed season –somesitesinBelizehavebeenprotectedsince2002.DuringtheBahamianclosedseason,specialprotectionisgivenforthehighCay,Androsspawningaggregationsitewhichisdesignatedasa‘ProtectedArea’.Allfishingisprohibitedinthisareaforthefulldurationclosedseason.however,duetochallengesinenforcement,anMPAatthislocationismorefeasible.
• Scientific Research–moreresearchisneededsothattheinformationcanbeusedtoguidepolicy.Someofthequestionsthatscientistswouldliketoanswerare:
Canaggregationsthathavedisappearedreforminnewareasoragaininthesamearea?
ArefishindifferentregionsinTheBahamasspawningatthesametime?
Doindividualfishspawnmorethanonceperseason?
BerryIslandsECLSP GreenCayGreat/LittleExuma
2000
1500
1000
500
0MeanNassauGroup
erbiomass(g/120
m2 )
Areas in Central Bahamas
MPA
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Doindividualsreproduceeachyearandifso,dotheyalwaysgotothesamesite?
Whatistheminimumnumberoffishrequiredatanaggregationsiteforspawningtooccur?
WhatarethecharacteristicsofthebesthabitattypesforjuvenileNassaugrouper?
WhatisthestatusofNassaugrouperstocksthroughoutTheBahamas?
Wheredolarvaespawnedataparticularsitego?
Additional conservation measures that should considered:
•Communityconsultationandeducationprogrammes.
•InclusionofaggregationsiteswithintheboundariesofMarineProtectedAreas.
•Increasingtheminimumharvestablesizefrom3+lbsto5+lbs,whichisclosertotheaveragesizeof sexuallymatureNassaugrouper.
•BREEFdoesnotsupporttheexportofNassaugrouper.Thiswillhelptoensurethatthefishisavailableforlocalconsumption.
•Enforcementofexistingseasonalclosures.
•Legislationforafixedclosedseason.
•CompleteprohibitionofthesaleofNassaugrouperduringtheclosedseason.
•AddresstheproblemofillegalpoachinginBahamianwaters.
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species 15
Why is an annual closed season with legislated fixed dates important? To provide permanent protection for Nassau grouper during its breeding season. To reduce confusion regarding the dates of the closed season. With advanced knowledge of the closed season dates the fishing community, seafood processors and consumers can prepare just as they do for crawfish.
Case StudyThe Grouper Moon Project & the Cayman Islands Example
TheCaymanIslandssupportthelargestknownaggregationofNassaugrouperintheworld.AfteritsdiscoveryonthewestendofLittleCaymanin2001,ReefEnvironmentalEducationFoundation(REEF)*andtheCaymanIslandsDepartmentofEnvironment(CIDOE)launchedagroundbreakingresearchandeducationprogram,knownastheGrouperMoonProject,tostudytheaggregation.AftertwoyearsofsignificantharvestattheLittleCaymansite,theCaymanIslandsgovernmentissuedan8-yearbanin2003onfishingforNassaugrouperatallcurrentandremnantaggregationsites.
REEFandCIDOEhavecoordinatedannualeffortstomonitorandstudytheLittleCaymanaggregation,aswellasseveralremnantaggregationsonCaymanBracandGrandCayman.TheGrouperMoonProjectresearchhasgrowninscopetoincludeanambitiousacoustictaggingproject,juvenilehabitatresearch,geneticstudies,multi-speciesinvestigations,andadrifterprojecttounderstandhowcurrentsandotheroceanographicconditionsaffectgrouperlarvaerecruitment.Thisintensiveresearchhasindicatedthatthepolicyactionsareindeedworking.Attheendof2011,basedonfindingstodate,theCaymanIslandsMarineConservationBoardextendedtheprotectionsforanadditionaleightyears,andabroaderpackageofharvestrulesaimedtomaximizelong-termNassaugrouperconservationiscurrentlyunderreview.Theseincludeaclosed,no-takeseasononNassaugrouperfromNovember–April,aslotsizelimitallowingtakeofindividualsbetween16”–24”,andadailybaglimitof4fishperpersonperday.Inaddition,duetotheextensiveuseofspawningsitesbydozensofotherfishspecies,ithasbeenrecommendedthattheseimportantplacesbeclosedtoharvestyear-round.Whilethisisaclearmanifestationofprojectsuccess,theCaymangovernmentknowsthatit’simperativetodocumentcontinuedrecoveryofthespecies,andpromotesustainedsupportforNassaugrouperconservationintheCaymansandelsewhere.
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species16
Grouper Moon Education Program
Toensurelong-termsuccessandeffectiveconservationofNassaugrouper,REEFandCIDOEhaveconductedextensiveoutreachthroughnewsmedia,publicserviceannouncements,printedmaterial,anddocumentaries.WithsupportfromDisneyWorldwideConservationFundbeginningin2011,REEFbeganworkingonthecreationandimplementationofaneducationprogramdesignedforelementaryandhighschoolstudents.ThecurriculumfocusesonbringingtheNassaugrouperintoCaribbeanelementaryandhighschoolclassroomsthroughlessonplansandlive-feedwebcaststhatconnectstudentsintheirclassroomswithscientistsinthefield.Theseuniqueandexcitinglivewebcastsutilizestate-of-the-artunderwatervideotechnology,allowingstudentstoengagewithGrouperMoonscientistsandvirtuallyexperiencewhatit’slikeswimmingamongthethousandsofNassaugrouperthatgatheronthewestendofLittleCaymanduringwinterfullmoons.
ForfurtherinformationabouttheGrouperMoonProject,visitwww.REEF.org/groupermoonproject.TolearnmoreabouttheCaymanIslandsDepartmentofEnvironment,visitwww.doe.ky.
*REEFisaUS-based,non-profitorganization,it’smissionistoconservemarineecosystemsbyeducating,enlisting,andenablingdiversandothermarineenthusiaststobecomeactiveoceanstewardsandcitizenscientists.Whilesimilarinname,REEFandBREEFarenotaffiliated.however,BREEFcollaborateswiththeGrouperMoonProjectpartnersoneducationandoutreacheffortsfocusedonNassaugrouperspawningaggregations.
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species 17
aQuaculTure— fish farming is this a feasible solution?Aquacultureistherearingofaquaticorganismsinacontrolledenvironment.Today40%ofthefisheatenintheUSisfarmraised.Canaquacultureplayaroleinhelpingtoconserveourlocalfisheries?
Aquaculturecanposemanychallenges.Thesuccessoffarmingaquaticorganismsdependsonseveralfactorsincludingthetypeoforganism(nativevs.non-nativespecies,herbivorevs.carnivore),sourceoffeed,costofequipment,andimpactontheenvironment.Aquaculturefacilitiescanimpacttheenvironmentthroughhabitatdestruction,pollution,intentional/unintentionalreleaseofnon-nativespecies.Whilethepotentialforsupplyingseafoodthroughfishfarmingisgreat,measurestoconservewildpopulationsmustbeimplementedtoprotectourculture,livelihoodsandnaturalheritage.
Pros
• Reduces fishing pressure on wild fish/conch stocks.
• Creates jobs, revenue and provides opportunities for local investment.
• It increases scientific knowledge e.g. understanding of the life cycle, of the resource so that we can make informed decisions about their management.
• Farm raised organisms can potentially be released into the wild to boost wild stocks. However, this has not been successful because the farm raised species often lack the natural behaviours which help them to survive in the wild e.g. predator evasion.
Cons
• Construction of aquaculture facilities often impact natural nursery habitats such as wetlands.
• Farming of carnivorous species such as Nassau grouper would impact wild fish populations
because fish are harvested from the wild to feed the farmed fish.
• Increases the risk of disease transmission and parasites from farmed to wild populations.
• By-products of the industry such as, chemicals used to treat parasites, excess nutrients in feed and waste often causes water pollution.
• Fish farms may threaten the livelihood of fishers.
• Farms are susceptible to weather, predators and disease so measures must be taken to counteract these which are often expensive.
• Species chosen for aquaculture are often hardy species that can grow and reproduce quickly. When they are non-native to a particular region, these characteristics can make them particularly damaging invasive species.
• Costs are often high.
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species18
A. Fish adaptations – Design a fishBackgroundinformation:studentsshouldunderstandhowthephysicaladaptationsoffishallowthemtosurviveintheirenvironment.
Materials:paper/card,coloredpencils Task:ChallengeeachstudenttocreateanIDcardfortheirownnewlydiscoveredfishspecies.
INSTRUCTIONS TO STUDENTS:1.Onthefrontofthecardmakeadrawingofyourfishshowingitsphysicaladaptationsandwriteits imaginaryscientificnameandcommonnames.
2.Writeaparagraphonthebackofthecardexplainingwherethefishlivesandtheadaptationsthatyourfishhasthathelpsittosurviveinitschosenhabitat.
3.Studentsshouldusethecardstotelltheirclassmatesabouttheirnewlydiscoveredspecies.
4.Displaycardsintheclassroom.
SupportingClassroom Activities
Grouper 101
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species 19
B. Fishing for the Future - Fishing Simulation Activity Time: 30 minutes
OVERVIEWInthisfishingsimulationactivity,studentswillmodelseveralconsecutiveseasonsofaNassaugroupercommercialfishery.Theywillexplorehowfishingtechnology,populationgrowth,andsustainablepracticesimpactfishcatchandfisheriesmanagement.Asstudentsprogressthroughthefishingseasonstheyarelikelytooverfishtheiroceansandwillhavetomigratetootheroceanstomeettheirbasicneeds.Mostgroupswilleventuallycreateatotalcrashoffishstocksinalltheoceans.Thisdemonstrationwillclearlyindicatethebenefitsofsustainablefishingpractices.
Objectives:Studentswill:1.Modelthefactorsthatcanresultinoverfishing.2.Discusssocial,environmentalandeconomicimpactsofoverfishing.3.Identifysustainablefishingpractices.
Materials:hardcandye.g.M&Ms(two14-ouncebagsforupto30students),onecupperstudent,onestrawperstudent,onesmallbowlpergroup,onespoonpergroup,stopwatch
BEFORE YOU BEGINDividetheclassintogroupsofupto5students.Put30candiesineachbowl.Selectonestudentineachgrouptoactasamoderatori.e.torecordcatches,identifystudentswhowereunabletocatchtheirquotaandtoaddadditionalcandiestothebowlaftereachround.
INSTRUCTIONS1.Explainthegamerules:
•Eachstudentisafisherwhoselivelihooddependsoncatchingfish.•Thecandiesrepresentfishintheocean.
•Eachfishermustcatchatleast2fishineachroundtosurvive(i.e.oneforpersonalconsumptionandtheotherforsale).Thegreaterthenumberoffishcaughtthegreatertheearningsofthefisher.
•Whenthefishingseasonopensforeachround,studentsmustfollowinstructionsgivenforfishingi.e.fisheriesregulations.
•Fishingisnotpermittedbetweenrounds(closedseason).
•Whentheseasonclosesaftereachround,theremainingfishineachbowlrepresentsthebreedingpopulation.
•Onenewfishwillbeaddedtothebowlattheendofeachroundforeveryfishthatisleftintheocean.
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species20
2.Giveeachgroup:abowl(ocean)with30Candies(fish)andhavethemnametheirocean.
3.Giveeachstudentastraw(fishingrod)andcup(fishingvessel)inwhichtheymustplacethefish thattheycatch.
ROUND 1 Fisheries Regulations–Studentshave20secondstofish.Studentsshouldusethestrawtofishwhileholdingtheirhandsbehindtheirbacks.Fishingduringtheclosedseasonwillresultindisqualification.
Attheendofeachround:•haveeachfishercounthis/hercatch(candiesincup)andrecordtheircatch(fisher’slog).
•Calculatethenumberoffishcaughtineachroundi.e.Numberoffishincupminusthenumberoffishcaughtthepreviousseason.
•Calculatethevalueofthecatch,usingarateof$50perfishi.e.50multipliedbythenumberoffishcaught.
•Recordthenumberoffishthatremaininthebowl.
•Aftereachround,fisherswhodonotcatchaminimumoftwofishmustsitoutforthefollowinground,afterwhichtheymayreturntothegame.
•Themoderatorshouldaddonenewfishforeveryfishleftinthebowl(ocean).
ROUND 2Fisheries Regulations–Studentshave20secondstofish.Theremainingstudentsshouldholdthestrawintheirhandstofish;[thisrepresentsnewtechnologysuchasafastervesselorfish-findingsonar.Thesuccessfulfisherswereabletopurchasethesewiththeprofitsofthepreviousfishingseason].Fishingduringtheclosedseasonwillresultindisqualification.
ROUND 3 Afterthesecondfishingseason,givethemostsuccessfulfisherineachgroupaspoontouseinsteadofastraw.Thisrepresentsinequityinthefishingindustryinwhichsomefishersutilizemoreadvancedfishingtechnologysuchas,electricfishingreels.Continuethegameforroundthree.
ROUND 4Ifstudentshavedepletedtheiroceans,allowthemtoinvadeotheroceans.Donottellthemthatthattheycandothisbeforehand.Fishersmayeithergoasagrouptooneoceanordispersetoseveraloceans.
Season Number of Fish in Cup Number of Fish CaughtValue of Catch@ $50 per Fish
Number of Fish left in the Ocean
1
2
3
SAMPLE FISHER’S LOG
GUIDEFORBAhAMIANSChOOLSThe nassau Grouper: an Iconic Bahamian Species 21
Additional Rounds -Repeatfishing,recording,andreplenishmentoffishstocksuntileithersustainablefishingisachievedoruntilallormostgroupsdepletetheirstocks.
Discussion Questions
Usethefollowingsamplequestionstohelpstudentstoreflectabouttheactivityandhowitsimulatesrealworldfisheryissues.
• How did you feel when you realize that you had depleted your fish stock?
• How did you feel when other fishers joined your group?
• How does this activity relate to real oceans and fishery issues?
• What happens to a resource when you have infinite population growth, growing technology and a finite resource?
• To whom do the fish in the ocean belong?
• How do the actions of consumers and fishers impact the resource?
• Who is responsible for taking care of the resource?
• Introduce and discuss the concept of sustainability using the following definition: “Meeting the needs of the present without compromising the ability of future generations to meet their own needs.”
• Ask why sustainability may be an important goal for a society and what might be difficult about realizing this goal?
• What actions can we take to ensure a sustainable Nassau grouper fishery?
SourcesReferencedforthisguideinclude:
Bestor,C.“BiologicalProfilesNassaugrouper”.FloridaMuseumofNaturalhistory.DownloadedonJune102008.www.flmnh.ufl.edu
Cheung,W.,Sadovy,Yetal.ArethelastremainingNassaugrouperEpinephelus striatusfisheriessustainable?StatusquoinTheBahamas.EndangeredSpeciesResearchVol.2027-39,2013PublishedonlineFebruary22
Cornish,A.&Eklund,A.M..“Epinephelus striatus”.In:IUCN2007.2007IUCNRedListofThreatenedSpecies.Publishedin2003.Downloadedon11June2008.
humann,P.,DeLoach,N.ReefFishIdentification:FloridaCaribbeanBahamas(3rded.).Jacksonville,FL:NewWorldPublications,Inc.(2002)
MacalisterElliott&PartnersLtd.BREEF.FisheriesmanagementActionPlanforTheBahamas.ReporttotheBahamasDepartmentofFisheries.1998.
MaljkovicA.,VanLeewenT.E.Predationontheinvasiveredlionfish,Pterois volitans(Pisces:Scorpaenidae),bynativegrouperintheBahamasCoralReefs.2008.
Sadovy,Yvonne,andAnne-MarieEklund.SynopsisofbiologicaldataonNassaugrouper,Epinephelus striatus(Bloch,1792),andthejewfish,E. Itajara(Lichtenstein,1822).U.S.Dep.Commer.,NOAATech.Rep.NMFS146,andFAOFisheriesSynopsis157,65p.1999.
WoodsholeOceanographicInstitution.[MapshowinggeographicdistributionofNassaugrouperIllustrationbyJackCook/WhOIGraphicServices].www.flmnh.ufl.edu.
©2014ApublicationofTheBahamasReefEnvironmentEducationalFoundationUnit11,CavesProfessionalCenter,CavesVillage,WestBaySt.P.O.BoxCB11005,Nassau,TheBahamasTel:327-9000,Fax:327-9002Email:[email protected]
Photographs and Illustrations:Catherine
Booker,CraigDahlgren,Jimhellem,Josh
Stuart,Paulhumann,SandraVoegeli,Stuart
Cove’sFinPhoto,TheDepartmentofMarine
Resources,BREEF,WoodsholeOceanographic
Institution
FundinggenerouslyprovidedbyLyfordCayFoundation,Inc.
AdditionalsupportprovidedbyTheGrouperMoonProject
BREEFgratefullyacknowledgesthe
followingpeopleandorganizationsfortheir
contributionstothisEducator’sGuide:
CharleneCarey,CraigDahlgren,Lester
Gittens,CasuarinaMcKinney-Lambert,
Dr.YvonneSadovy,ChristySemmens,
KristaSherman,RebeccaStrachan,The
DepartmentofMarineResources,REEF,The
GrouperMoonProject,theCaymanIslands
DepartmentoftheEnvironment.
Bahamas Reef environment educational Foundation
ThisworkislicensedunderaCreativeCommonsAttribution-NonCommercial-ShareAlike4.0InternationalLicense.