dolphin watch - fin book

2nd Edition – June 2012

An identification catalogue for dolphins observed in the Swan Canning Riverpark

FinBook

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Foreword

As Chief Scientist of Western Australia it has been my pleasure and privilege to follow the splendid development of the Dolphin Watch Project. The dolphins in our South West estuaries are part of Western Australia’s environmental, social and cultural heritage. So it is great to know that five dolphin mothers have new calves in the Swan and Canning rivers this year.

The FinBook is making a key contribution to enhancing ‘citizen science’ as part of initiatives to support the health of our dolphin population. I commend this book to you and acknowledge the part it is playing in ensuring that community contributes significantly to protecting our precious environment.

Professor Lyn Beazley AO FTSE

Chief Scientist of Western Australia

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Table of Contents

Foreword ..............................................................................2

Welcome to FinBook ............................................................4

How to use FinBook .............................................................5

FinBook catalogue

Dolphins regularly sighted in the Riverpark .....................8

Dolphins occasionally sighted in the Riverpark ................20

Notes on individual dolphins ................................................22

Dolphin research in the Riverpark ........................................23

Dolphins in the Riverpark .....................................................24

Dolphin Watch ......................................................................26

Caring for dolphins in the Riverpark .....................................27

Glossary ...............................................................................29

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Welcome to FinBook

Welcome to FinBook 2012. FinBook is a catalogue of the bottlenose dolphins (Tursiops aduncus) observed within the Swan Canning Riverpark. This edition of FinBook catalogues the dolphins observed in the Riverpark between July 2011 and June 2012.

Using FinBook, community members can recognise individual dolphins and contribute information to assist in monitoring these unique residents of the Swan and Canning rivers. We also hope that FinBook will help people think of these wonderful creatures as unique individuals with long, complex lives that unfold right before our eyes.

FinBook is designed for river-goers of all ages and interests, so that everyone can play their part in keeping dolphins part of the estuary ecosystem.

Dr Hugh FinnMurdoch University

Dr Chandra SalgadoCurtin University

Delphine ChabanneMurdoch University

Marnie GiroudSwan River Trust

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How to use FinBook

Dolphins can be identified by the markings and nicks that are present on their dorsal fins. Many of these markings are permanent, thus allowing for dolphins to be monitored over time. Some dolphins are hard to identify because of a lack of markings and are known as ‘clean fins’.

FinBook is like a catalogue of ‘fin-prints’ for dolphins. The tables in FinBook show the right and left sides of each dolphin’s dorsal fin. FinBook also describes other unique features that can be used to identify individuals.

This is Arrow. Note the nicks along the dorsal fin (indicated by the arrow). The white marks on the fin and body are caused by the teeth of other dolphins. While the ‘rake marks’ will fade over time, the nicks on the fin will remain.

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Each dolphin has a profile showing images of the left and right side of the dorsal fin and providing information such as age-class (calf, juvenile, adult) and sex (where this is known).

Ten of the dolphins in FinBook were first identified during previous research studies in Cockburn Sound from 1993 to 1997 and in Cockburn Sound and the Swan River from 2001 to 2003. The year in which they were first observed is provided for all dolphins.

Some of the profiles also contain notes on notable marks, which are unique scars or other markings that are useful for identification.

Backpack is a male from Cockburn Sound. He was first sighted in 1993. His male alliance partner is Fingers. They are occasionally sighted in the Riverpark.

Backpack in 1995 (above) and in 2009 (right)

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FinBook is divided into two sections based on the frequency individual dolphins were observed in the Riverpark during the past year:

(1) dolphins regularly sighted in the Swan Canning Riverpark (22 dolphins).

(2) dolphins infrequently sighted in the Swan Canning Riverpark (3 dolphins).

Each dolphin has a profile that provides:

• the dolphin’s name (including any old names or former identifiers);• images of the left and right side of the dorsal fin (where available);• the dolphin’s age-class (adult/juvenile/calf); and• the dolphin’s known or suspected sex.

The dolphin profiles are clustered according to patterns of association. Like humans, dolphins are very social animals and tend to have long-term ‘associates’. We have organised FinBook so that dolphins appear among their known associates – so if you see one of these dolphins chances are that their associates might be somewhere near by.

For example, Daniele and Highnitch are regularly seen together and are considered to be associates of each other. Similarly, the dolphins Hii, Arrow, Bottomslice and Blackwall are often found together; these four dolphins are suspected males.

Mother-calf pairs are also grouped together. Mothers and their dependent calves are almost always seen together, so if you see one of the mothers, her calf will not be too far away. However, some calves are very independent, and two or more calves may play and interact with each other while their mothers are searching for fish.

Some notes on individual dolphins and a glossary are also provided at the end of this booklet.

Dolphins regularly sighted in the Swan Canning Riverpark

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Group 1 - suspected males usually seen together

Left side Right side

Name HiiSex Suspected maleAge AdultFirst recorded 2001

Name Arrow (UNK 16)Sex Suspected male Age AdultFirst recorded 2009


9


Name BottomsliceSex Suspected maleAge AdultFirst recorded 2001

Name Blackwall Sex Suspected male Age AdultFirst recorded 2001

Identifying feature Hunk missing out of peduncle (probable old shark attack wound)


10


Name Extreme(UNK 21)Sex UnknownAge AdultFirst recorded 2009

Name Print (UNK 33)Sex UnknownAge AdultFirst recorded 2009

Group 2 - adults and sub-adults often seen together


11


Name Pebbles(UNK 25)Sex UnknownAge AdultFirst recorded 2009

Name PanuniSex UnknownAge Sub-adultFirst recorded 2011


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Name HighnitchSex FemaleAge AdultFirst recorded 2001Mother ofHighhope

Name HighhopeSex UnknownAge CalfBorn July 2011Calf ofHighnitch

Group 3 - Highnitch and Daniele


13


Name DanieleSex Suspected femaleAge AdultFirst recorded 2009


14


Name MoonSex FemaleAge AdultFirst recorded 2001Mother of Night

Name NightSex UnknownAge Calf - about three years oldCalf of Moon

Group 4 - dolphins sometimes seen with other mother-calf pairs or females


15


Name TupacSex FemaleAge AdultMother of Gizmo

Name GizmoSex UnknownAge Calf - about three years oldCalf of Tupac


16


Name Pirulli(UNK 18)Sex FemaleAge AdultFirst recorded 2009 Mother of Soul

Name SoulSex UnknownAge Calf - about one year oldCalf of Pirulli


17


Name Akuna(UNK 32)Sex UnknownAge AdultFirst recorded 2009

Name Claw (UNK 47)Sex UnknownAge AdultFirst recorded2009

Sometimes seen with Moon and/or Tupac and their calves


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Left side

Name Dunedoo(UNK 19)Sex UnknownAge AdultFirst recorded 2009

Seen with Moon and/or Tupac and their calves


19


Name TworakesSex FemaleAge AdultFirst recorded 2001Mother of Zari

Name ZariSex UnknownAge Calf - three to four years oldCalf of Tworakes

Group 5 - Tworakes and calf

Named in memory of Zari Ryan (age 12), who had an enduring love for dolphins. Zari, a fun-loving Perth girl, sadly passed away from leukaemia in 2009.

Dolphins occasionally sighted in the Swan Canning Riverpark

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Name BackpackSex MaleAge AdultFirst recorded 1993

Name FingersSex MaleAge AdultFirst recorded 1993

Male alliance

Cockburn Sound resident. Only observed in Inner Harbour and coastal areas

Cockburn Sound resident. Only observed in Inner Harbour and coastal areas

Dolphins occasionally sighted in the Swan Canning Riverpark

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Left side

Name NeckSex MaleAge Adult

Solitary male

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Notes on individual dolphins

The dolphins in the Swan and Canning rivers were studied intensively from October 2001 to June 2003. During that time Murdoch University researchers identified 55 dolphins in the Swan Canning Riverpark and Fremantle Port (Inner Harbour). Of those dolphins, about 20-25 dolphins were considered to be ‘resident’ within the estuary, with the number varying depending on the number of calves present.

This edition of FinBook includes nine of the 2001-3 residents: Blackwall, Bottomslice, Hii, Highnitch, Moon, Tupac, and Tworakes. We have also included Backpack and Fingers – these two males are resident in Cockburn Sound but make occasional forays into the estuary looking for females.

From July 2011 to April 2011, we identified 39 dolphins within the Swan Canning Riverpark and Inner Harbour for the Port of Fremantle. Many of these dolphins are observed only in the Inner Harbour and not in the Riverpark (i.e. they do not venture into the estuary). Dolphin groups sighted in Inner Harbour often include both ‘river’ dolphins and dolphins from coastal areas. All of the ‘river’ dolphins also range within coastal habitats near Fremantle, so they spend part of their lives within the estuary and part in the ocean outside.

Some of the dolphins from coastal areas (e.g. the male alliance of Fingers and Backpack) occasionally venture into the estuary, though usually only into the lower reaches.

Twenty-two dolphins were consistently observed within the estuary over this period and we consider them to be resident within the Swan Canning Riverpark. Included among these 22 dolphins are five dependent calves: Night (calf of Moon), Gizmo (calf of Tupac), Soul (calf of Pirulli), Highhope (calf of Highnitch) and Zari (calf of Tworakes).

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Dolphin research in the Riverpark

Coastal and Estuarine Dolphin Project

Research for the Coastal and Estuarine Dolphin Project (CEDP) is driven by the belief that the best future for Perth’s dolphins lies with ecosystems that are healthy and resilient and with communities that are actively engaged in caring for their local dolphin populations and the environments they inhabit.

CEDP (http://mucru.org/) is a collaborative research program addressing the health, ecology and conservation of dolphins in the Perth region. Murdoch University and Curtin University established CEDP as a response to the deaths of six dolphins within the Swan River in 2009. CEDP works in partnership with state and local government, industry and the community of Western Australia.

Current CEDP Research

CEDP is a comprehensive assessment of the status of dolphins in an area extending from Rockingham to Scarborough along the coast and inland to the City of Perth. This area encompasses Cockburn Sound, Owen Anchorage, Gage Roads and the Swan-Canning Estuary. The objective of this research is to determine the structure and connectivity of dolphin populations within the Perth area. The resident dolphin community in the Riverpark is very small, so it is vital that we understand its status and connections to other populations.

CEDP research also analyses sighting information collected by Dolphin Watch volunteers. This research involves the application of innovative statistical approaches.

The overall objectives of CEDP are to:• conduct rigorous and innovative research into the ecology of dolphins

in the Perth region;• provide scientific information and advice to industry and government to

support the conservation of dolphins and their habitat; and• share information and expertise with the public to improve community-

based conservation and monitoring for dolphins.

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Dolphins in the Riverpark

Dolphins are a unique part of the Riverpark. What do we know about the ecology of the dolphins inhabiting the Canning and Swan rivers?

A resident community

The Riverpark is home to a resident community of about twenty dolphins. These dolphins account for nearly all of the sightings of dolphins in the Riverpark, although dolphins from nearby coastal areas are occasional visitors.

The dolphins are classified as ‘resident’ because they use the estuary year-round. Based on our knowledge of bottlenose dolphins elsewhere, these are also likely to be life-long residents of the estuary. Seven of the residents were first identified in 2001, when the first research on the Riverpark dolphins was undertaken. Two of the occasional visitors – the males Fingers and Backpack – were first sighted in Cockburn Sound in 1993.

The dolphins resident in the Riverpark are said to comprise a ‘community’ of dolphins because they range over similar areas (the Riverpark and adjacent coastal waters) and frequently interact and associate with one another. These ranging and association patterns distinguish them from other dolphins that may be resident in Cockburn Sound or Owen Anchorage.

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A life between the ocean and the estuary

The dolphins in the resident community spend part of the lives in the coastal areas outside of the Riverpark, sometimes venturing as far as Cockburn Sound to the south and Gage Roads to the north. They move between the Riverpark and the coastal waters on a daily or near-daily basis. Thus, their lives are like a see-saw between the ocean and the estuary.

Though dolphins are most frequently sighted in the lower and middle reaches of the Canning and Swan rivers, they sometimes travel up into the upper reaches of both rivers. Where the dolphins go and when they go there will reflect patterns in the abundance and distribution of their prey.

Important prey for dolphins in the Riverpark include mullet, herring, whiting, and cephalopods (e.g. squid, cuttlefish and octopus). They are also likely to feed at least occasionally on black bream and other fish species. Dolphins can’t chew, so if they catch prey that are too big to swallow whole, they must break them into smaller pieces. They do this by throwing them around at the surface or by rubbing them along the sediment at the bottom.

Foraging (searching for fish) is the main activity of dolphins within the Riverpark. Most dolphins will need to consume upwards of 10 kg of fish a day – that’s a lot of fish, so it’s easy to see why dolphins are always on the look-out for a feed.

Dolphins will forage anywhere in the two rivers and in any kind of habitat. So you may see them chasing mullet in the shallows along the shore, preying on herring in the deeper water, or trying to corral octopus amongst the pens in a marina.

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Dolphin Watch

The Swan River Trust, Murdoch and Curtin universities created a social science research and education project called Dolphin Watch which involves the community as citizen scientists in researching bottlenose dolphins in the Swan Canning Riverpark.

Researchers from Curtin and Murdoch work with the Trust’s River Guardians program to train Dolphin Watch volunteers in techniques for monitoring the movement and behaviour of dolphins in the Riverpark.

Community involvement is a great boost to the research and allows large amounts of information to be gathered on how dolphins use the Riverpark that could not be gathered through conventional scientific research programs.

The public plays an essential role in monitoring this iconic species as citizen scientists. By becoming a member of the River Guardians program the public becomes more informed on river conservation issues and can participate in activities to help the rivers and the animals living within them. With 425 trained Dolphin Watchers observing dolphins, the information is helping to provide more observations to be analysed by research scientists.

Since Dolphin Watch began, volunteers have contributed photographs and observations of the locations and behaviours of dolphins in the Riverpark. Originally this was confined to the upper reaches of the Swan and Canning rivers, however the entire Riverpark is now being monitored due to public insistence. Volunteer information and photographs help build a picture of the community of dolphins in the system.

The Dolphin Watch project will continue to develop and change over time to expand research capabilities and to encourage volunteers to participate through online monitoring and other initiatives.

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Caring for dolphins in the Riverpark

It’s easy to help care for dolphins in the Swan Canning Riverpark by following these simple rules.

Keep your distance – never approach a wild dolphin and make sure you keep at least 30 metres away if you’re in the water or 100 metres if you’re in a boat.

Slow down for dolphins - dolphins often form resting groups in the middle reaches of the estuary, so keep an eye out for dolphins, and slow down if you spot any.

Never feed dolphins – it is illegal and leaves them vulnerable to entanglement, boat strikes and disease.

And finally, take rubbish home with you or dispose of it in a rubbish bin. When fishing on the rivers please fish responsibly. Dolphins, particularly calves, can get tangled in fishing line. Make sure you dispose of unwanted fishing line in a proper rubbish bin, use a biodegradable line and take only what you need to maintain fish stocks.

If you see dolphins in distress, please call the Department of Environment and Conservation’s (DEC) WILDCARE Helpline on (08) 9474 9055. WILDCARE Helpline provides 24-hour state-wide referral to a dedicated group of volunteer wildlife carers and professionals for anyone who finds sick, injured or orphaned native wildlife.

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Reducing nutrients to care for dolphins in the Riverpark

The Swan and Canning rivers are an important habitat for bottlenose dolphins. It is a place that they bring their calves and where they come to socialise and feed. Good quality habitat in the river system will continue to support the growth, survival and reproduction of these dolphins.

There are abundant fish resources in the river system with over 130 fish species and a multitude of invertebrates, including crabs, prawns and molluscs.

Keeping our dolphins in the rivers system means looking after the ecological health of the system so that these food resources in their river habitat remain available and abundant.

Nutrients and organic loading threaten ecological health and habitat value by promoting algal blooms, deoxygenation and fish kills.

We know from the Swan Canning Water Quality Improvement Plan that we need to halve the amount of nutrients in the system in order to protect water quality and ecological health.

Everyone living in the catchment has a role to play in reducing nutrients and protecting dolphin habitat. You can do this by:

• Only applying fertiliser when it’s needed in spring or early autumn – follow application rate instructions, don’t over apply and never over water.

• Growing local native plants – they need less water and fertiliser, and attract native birds, lizards and insects.

• Composting your leaves and grass clippings so they don’t wash into drains and add nutrients to the rivers.

• Keeping garden weeds away from drains - they may end up in rivers and overtake foreshore vegetation.

Check out our www.riverguardians.com for more helpful tips and information.

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Glossary

Calf – a dolphin still dependent upon its mother, usually < 5 years old

Dorsal fin – the fin on a dolphin’s back (its ‘dorsal’ surface)

Juvenile – a young dolphin, usually about 4–10 years old

Leading edge (of dorsal fin) – the front edge of the fin (vs. ‘trailing edge’)

Peduncle – an anatomical term for the tail stock of a dolphin

Sub-adult – a dolphin that is not quite adult-size but larger than a juvenile

FinBook

Project partners

Supported by Contact us

Swan River Trust River Guardians Program9278 0971 [email protected]

Murdoch Cetacean Research Unithttp://mucru.org/

Curtin University Centre of Marine Science & Technologyhttp://cmst.curtin.edu.au/

dolphin watch - fin book

Documents

finbook catalogue dolphins

individual dolphins

edition of finbook

dolphins dorsal fin

canning rivers

catalogue of fin

dolphin mothers

dolphin population