Riverpark Dolphin

Junior

Classification Kingdom Animalia Phylum Chordata Order Cetacea Class Mammalia SuborderOdontoceti Family Delphinidae Genus Tursiops Species Aduncus

Life Span

Females: 40+ years Males: 35+ years

Size

An average-sized adult is 1.8-2.43 metres long and weighs up to 230 kilograms

Reproduction

•Gestationis12months

• Females have one calf about once every 4 years

•Femalescanhave8calvesintheirlifetime

• A calf stays with its mother for 3-5 years

•Femalesmayfirstcalveataroundage10-12yearsold

•Malesmightnotmatesuccessfullyuntilmuchlaterduetointensecompetitionforaccesstofemales

Lesson plan 7 - Threats & solutions

Background information

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The dolphin with the white patch was named Kwillena by a Dolphin Watcher Photo: Hugh Finn

• Females have a network of female friends

• Males usually bond closely to one another and form a long-term partnership known as an alliance

•Afterweaning,juveniledolphinsspendseveralyears learning about their environment and the dolphin

societytheyinhabit.Duringtheseyears,theylearnimportant social and feeding skills they will need to survive as adults.

Social Structure

Scientificname:Tursiops aduncus

Commonname:Indo-PacificBottlenoseDolphin

SWAN CANNINGRIVERPARK

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Home ranges in the Swan and Canning Riverpark

•TheSwanRiverdolphinsdividetheirtimebetweentheestuaryandcoastalareas,suchasOwenAnchorage

•ThedolphinsareoftenseenintheCanningRiverand some will occasionally travel into the upper reaches of the Swan River

• Dolphin Watch volunteers help determine how far the dolphins travel upstream

• The dolphins most commonly seen in the riverpark use the rivers all year round and are thought to be long-term residents. It is likely that their mothers were also river dolphins

Community

•Itisestimatedtherearearound20-25dolphinsliving in the Swan Canning Riverpark

Status

• They are common in their range and protected by theWildlifeConservationAct1950

•InSharkBay,bottlenosedolphinsuseafeedingtechniquecalledsponging.To‘sponge’,dolphinstakeamarinespongefromtheseafloorandwearitontheirbeak(rostrum).Thespongeprovidesprotectionfortheirnosewhiletheyprobearoundontheseafloorforanimalshiddenin sand or under rocks.

•Untilrecently,allbottlenosedolphinswereconsideredmembersofonespecies,butnowscientistsrecognisetwospecies:theCommonBottlenosedolphin(Tursiops truncatus)andtheIndo-PacificBottlenosedolphin(Tursiops aduncus).InsouthwestWesternAustralia,CommonBottlenosedolphinsaregenerallyfoundwelloffshore,whileIndo-PacificBottlenosedolphinsoccur in coastal and estuarine areas.

•Incoastalandestuarineareas,bottlenosedolphinsaregenerallyobservedinsmallgroupsoflessthantendolphins.Intheopenocean,groupsmaynumberinthehundreds.

•Scientistsidentifydolphinsbypermanentmarksontheirdorsalfins.Thesemarkingsarescarsandallowfordolphinstobemonitoredacrosstheirlifetimes.

•MurdochandCurtinuniversitiesworktogetherwiththeSwanRiverTrusttomonitordolphinsin the rivers.

• River Guardians members can become Dolphin Watch volunteers and learn how to monitor dolphins in the rivers. www.riverguardians.com

Dolphin facts

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Dolphins in the Swan Canning Riverpark

•entanglementindiscardedfishingline•healtheffectsfromtoxiccontaminants• loss of habitat and decline in food species•poorwaterqualityfromnutrientcontamination• toxicalgalblooms•disturbancefromboattraffic•excessiveunderwaternoise• people illegally feeding dolphins which can lead to boat strikeandentanglement,astheycomeclosetoboats

• Keep your distance — never approach a wild dolphin. Stay at least 30 metres away if in the water or 100 metres away if in a boat

• Slow down—dolphinsoftenformrestinggroupsinthemiddlereachesoftheestuary,sokeepaneye out and slow down

• Never feed dolphins — it is illegal and leaves themvulnerabletoentanglementinfishinglinesorrope,boatstrikesanddisease

• Fish responsibly—dolphins,particularlycalves,cangettangledinfishingline.Disposeofunwantedmonofilamentlinecarefully,usebiodegradablefishinglineandcatchonlywhatyouneedwhilemaintainingfishstocks

• Bin any litter—rubbishsuchasplasticbagsandfishinglinecanseriouslyinjureorkillwildlife.Takerubbishhome,disposeofinbinsorpickuprubbish when you see it

• Report sick, stressed or injured dolphins — Department of Parks and Wildlife Helpline 94749055

• Prevent pollution—manyrivers,estuariesandcoastal waters near large urban development show signs of nutrient overloading and heavy metalcontamination.Toxicalgalbloomsareincreasingly common in estuaries and bays. Youcanhelpreducepollutioninriversby:

• Beingfertiliser-wiseathome–neverover-waterandonlyapplyfertiliserinspringorearlyautumn

• Wash your car on the lawn to keep detergents out of stormwater drains

• Growlocalnativeplantsinyourgarden• Pickupyourdog’swasteasitcanpromotealgal

blooms•Disposeofpaint,oilandchemicalsappropriately.

Ask your local council for help• Use phosphorous-free detergents to wash your

clothes• Keep garden weeds away from drains as they may endupasinvasiveweedsintherivers,andcompostleaves and clippings so they do not contribute to nutrients in the rivers

Solutions for looking after Riverpark dolphins

Threats to dolphins include:

Discardedfishinglinewrappedaroundthetailfinofthisdolphinpotentiallycaused this animal to die

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Class activity 1

1.Asapreparationactivity,providethebackgroundinformationtostudentstoreadthrough(excludingtheThreatsandSolutionsinformation(page2)asstudentswillberequiredtoworkshoptheseideas).

2.Bottlenosedolphinshaveafission-fusionsocialstructure,whichmeansthatgroupcompositionchangesfrequently(eg.onanhour-to-hourbasis,sometimesmoreorless).

3.Handoutstickynotesandtextas.Explainthatscientistsoftennamedolphinsaccordingtophysicalcharacteristicstheyseeontheirskinordorsalfin,includingnicks,cutsandscarsfromotherdolphinsandpredatorssuchassharks.Askeachgrouptonametheirdolphinaccordingtothephysicalcharacteristicstheycansee(eg.‘Spot’becausetherearespotsonthedolphin).

4.Askeachgrouptoidentifythreatstodolphinsintheriversandwriteeachthreatinredonaseparatestickynote.Stickeachnotewithathreattotheinflatabledolphin.

5.Rotatethedolphinsfromonegrouptothenext(askonestudentfromeachgrouptotaketheirdolphintothenextpod,clockwiseworksbest).Writeasolutionforeachofthethreatsinblacktexta(writtenandattachedtothedolphinfromthepreviousgroup)andattachtothestickynotewiththethreatwrittenonit.

What’s fun for you up top, can make our ears down here go pop!

Incompletingthisactivitystudentswill:

• identifythreatstodolphinsinourriverpark• developsolutionstoriverparkdolphinthreats• activelyparticipatewithingroupstoworkshopideas

Outcomes

• 4xinflatabledolphins(youcanpurchasefromToysRUsorClarkRubber,or,borrowthesefromtheSwanRiverTrust)

• 4xstickynotepads• 8xredandbluetextas

Preparation

ForstudentstolearnaboutIndo-PacificBottlenosedolphinslivinginthe SwanCanningRiverpark,investigatethethreatstothesedolphinsandworkshopsolutions.

Aim

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6.Inviteonepersonfromeachgrouptohandinallstickynotethreatsfrom theirgroup.Stickthethreattotheboardandcontinuetocollectthreatsfromeach group.Groupthedouble-upsintothemessuchasfishing(fishinglinerubbish,fishinghooks). Readoutthethreatsandsolutionsanddiscuss.

7.Discussanythreats/solutionsnotidentifiedbystudentsfromtheideasincludedinthebackgroundinformation.

Extension

Makeaposter,writeastoryorconductapresentationonhowtokeepourriversanddolphinshealthy.Thisactivitycouldalsobeextendedtobecomeanassessmentpiece.

Class activity 2

1. Conduct the Dolphin Quiz included in this lesson with students. Answers are provided.

Science curriculum links

Science and UnderstandingBiologicalSciences Year5(ACSSU043) Livingthingshavestructuralfeaturesandadaptations that help them to survive in their environment Year6(ACSSU094) Thegrowthandsurvivaloflivingthingsareaffectedby thephysicalconditionsoftheirenvironment

Science as a Human EndeavourUseandInfluenceofScience Year5(ACSHE217) Scientificknowledgeisusedtoinformpersonal Year6(ACSHE220) andcommunitydecisions

Cross-curricula links

ENGLISHLiteracyInteractingwithothers Year5(ACELY1699) Clarifyunderstandingofcontentasitunfoldsinformaland informalsituations,connectingideastostudents’own experiencesandpresentandjustifyapointofview Year6(ACELY1709) Participateinandcontributetodiscussions,clarifyingand interrogatingideas,developingandsupportingarguments, sharingandevaluatinginformation,experiencesandopinions

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Dolphin Quiz

Q. What species of dolphins live in the Swan Riverpark?

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Q.Howmanycalves(babydolphins)canafemaledolphinhaveinherlifetime?

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Q.Whyshouldn’tyoufeeddolphinsinthewild?

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Q.Howcanyoufishresponsibly?

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Q. What can you do at home to help keep our rivers and dolphins healthy?

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Dolphin Quiz - Answers

Q. What species of dolphins do we have in the Swan Riverpark?

Tursiops adunctusorIndo–PacificBottlenosedolphins

Q.Howmanycalves(babydolphins)canafemaledolphinhaveinherlifetime?8

Q.Whyshouldn’tyoufeeddolphinsinthewild?

Itisillegalandleavesthemvulnerabletoentanglement,boatstrikes,anddiseasewhentheyapproachhumansand boats

Q.Howcanyoufishresponsibly?

•Makesureyoudisposeofunwantedmonofilamentlinecarefullyasdolphins,particularlycalves,canget tangledinfishingline

•Usebiodegradablefishingline

•Takeonlywhatyouneedtomaintainfishstocks

Q. What can you do at home to help keep our rivers and dolphins healthy?

•Bewisewithfertiliserathome–neverover-waterandonlyapplyfertiliserwhenneededinspringorearly autumn

• Wash your car on the lawn to keep detergents out of the stormwater drains

•Growlocalnativeplantsinyourgarden

• Take your rubbish home with you and pick up rubbish when you see it

•Pickupyourdog’swaste,becauseit’sfullofnutrientswhichcanpromotealgalblooms

•Disposeofyourpaint,oilandchemicalsappropriately.Askyourlocalcouncilforhelp

• Use phosphorous-free detergents to wash your clothes. Phosphorous is one of the main nutrients that feed algal blooms

•Compostyourleavesandclippings.Ifwashedintostormwaterdrains,theycancontributetonutrient overload in the rivers

• Keep garden weeds away from drains as they may end up in the rivers as invasive weeds