Fishing line and plastic endangering young dolphins

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A leading Perth dolphin researcher is urging fishers to be extra vigilant with the proper disposal of fishing lines and hooks after seeing several of the marine mammals in Cockburn Sound caught up in discarded line.

Dr Delphine Chabanne, from Murdoch University’s Harry Butler Institute, said she had seen two young bottlenose dolphins within about eight months that had line wrapped tightly around their bodies. Others had been seen caught in line in previous years.

“We want people to understand the harm fishing line and other pollutants cause to marine animals, including dolphins,” Dr Chabanne said.

“Many of the animals recorded with fishing gear entanglement are calves or juveniles and as they grow the lines dig into their skin.“

Dr Chabanne, who is also researching dolphin behaviour as part of the Western Australian Marine Science Institution Westport Marine Science Program, said she feared what researchers saw from boats was the tip of the iceberg.

“More individuals may have injuries from fishing line gear that’s not always visible to us.  As an example, we don’t always get to see the pectorals and tail fin, or fluke, of individuals which makes it difficult to evaluate the full extent of fishing gear impact on dolphins.”

Dr Chabanne said the risk of fishing lines to the animal varied but it could result in death.

“There are some dolphins that manage to get rid of the line by themselves with minimal harm to their bodies but for others, the injuries are too serious and they die, which can be a slow process.”

Some dolphins had been euthanised when their injuries were considered too serious.

Dr Chabanne said line wasn’t the only danger to the animals.

“I have seen a dolphin with a plastic bag around its dorsal fin. If this was to become stuck around its blowhole it would suffocate,” Dr Chabanne said. “Plastic too is a problem when it breaks up into microplastics which are ingested by fish, the main diet of dolphins.”

Studying the elusive syngnathids of the Sound

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Dozens of Perth divers and keen underwater photographers are helping research into the seahorses and pipefishes of Cockburn Sound and Owen Anchorage as part of a project which will also see water-borne DNA tested for evidence of the beautiful but elusive animals.

The project forms part of the WAMSI Westport Marine Science Program and Dr Glenn Moore, the Curator of Fishes at Western Australian Museum, is leading a research team looking into the diversity and distribution of syngnathids, a family of highly specialized and often cryptic fishes that also includes seadragons.

The fish have national protection under the Environmental Protection and Biodiversity Conservation Act of 1999.

“They are one of the most challenging groups of fish to survey,” Dr Moore said.

“We can’t run fine nets over the reef because they get caught up and the fish are difficult to spot diving, so we are using multiple methods including looking at historical records.”

“We are using as many data sources as we can to try and compile as much information as possible about the syngnathids in the Sound.”

Dr Moore said citizen scientists had so far uploaded more than 1,000 images to an online portal along with the location where the fish were spotted.

He said one limitation of citizen scientists was they tended to head towards common dive areas where seahorses were well known but the information was still valuable.

Environmental DNA testing will also start soon on water collected from Cockburn Sound to add to information about their distribution.

“We have done some water sampling and we will do eDNA work in the next few months.

“We have frozen water samples and these will be analysed at a specialist laboratory at Curtin University.

“We are hoping we can start to build a picture of their distribution and habitat preferences,” Dr Moore said.

He said part of the eDNA work involved building a DNA library.

“You need to have something to match the eDNA to when we are doing the analyses.

“We need to get DNA from specimens we are looking for and that is a challenge because we don’t get to collect all the species we know are there.”

Dr Moore said most syngnathids lived in shallow coastal waters and were especially reliant on habitats well represented in Cockburn Sound, including seagrass, filter-feeder communities, shallow detritus, reefs and artificial structures.

He said the distribution, habitat preferences and abundance, particularly of seahorses and pipefish, wasn’t well known but the research aimed to find out more with the aim of improving their protection.

Photos: Western Australian Museum

Big pods and ‘fearless mums’ among the dolphins of Kwinana Shelf

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A dolphin with a distinctive white flash and a female bearing the scars of a shark bite, likely suffered while protecting her calf, were among about 120 individual dolphins recorded by researchers in the Kwinana Shelf area last year.

Dr Delphine Chabanne, from Murdoch University’s Harry Butler Institute, is leading the project which forms part of the WAMSI Westport Marine Science Program and involves monitoring dolphin distribution from Woodman Point to James Point within Cockburn Sound.

The dolphins that were recorded included 24 calves under two years of age.

The research team did the surveys from a boat travelling along parallel lines, 500 metres apart.

Dr Chabanne said 55 percent of the non-calf dolphins were re-identified from the last survey work between 2011 and 2015, indicating there are long term dolphin residents in Cockburn Sound.

“The long-term connection with other resident communities is also supported with four of the Swan Canning estuary resident male dolphins observed interacting with dolphins in Cockburn Sound,” Dr Chabanne said.

The team photographed the animals, noted their GPS coordinates and recorded water temperature and depth at the locations.

“One of the challenges was to make sure we have photographs for all dolphins when the groups are large,” Dr Chabanne said.

“We were seeing 15 to 35 dolphins in a pod, sometimes breaking into smaller groups then re-joining before breaking again into smaller groups all in less than 30 minutes. This fission-fusion behaviour is typical in bottlenose dolphins.”

Dolphin with shark bite mark on fin. Photo: Delphine Chabanne

Dr Chabanne said ‘Tippy’, one of the adult females, had a damaged dorsal fin from a shark bite.

“The females are more vulnerable to being attacked because the sharks will often target the calves and the mothers will work very hard to protect them.”

The first time ‘Tippy’ was recorded with fresh shark bites, her calf was only two months old. Two weeks later, ‘Tippy’ had suffered from further shark bites. The next time she was seen, unfortunately, her calf had disappeared.

Predation by other animals is not the only risk. Dr Chabanne said researchers spotted at least two calves with fishing lines around their bodies or pectorals.

Dr Chabanne said ’Tippy’, was first recorded in the early 1990s and is believed to be close to 40 years old. In fact, several individual dolphins observed in Cockburn Sound during the last year are between 30 and 40 years old.

Another female called ‘Jinx’, with a distinctive white mark on her back, is believed to be close to 30 years old and gave birth to a new calf this year.

Dr Chabanne said the average life expectancy for a female in the wild was 40 years, with males often not surviving beyond 35 because of fighting and riskier behaviour such as venturing into less protected areas.

The researchers are looking at where the dolphins in the Kwinana Shelf area spend most of their time during the year and working out why they are in certain areas.

Dr Chabanne said data was collected over four seasons to see how dolphins responded to changes in the environment.

Dolphin dreams a reality for WAMSI scientist

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On International Women’s Day, March 8, WAMSI Science Coordinator Dr Kelly Waples reflects on her career

As a young girl in beachside California, Kelly Waples dreamt of being a dolphin trainer from the first time she visited a marine aquarium. Her interest soon shifted from spectacle to science but a passion for the marine mammals remained.

Dr Waples, now a Principal Scientist for Department of Biodiversity, Conservation and Attractions and a Science Coordinator for Western Australian Marine Science Institution (WAMSI), ultimately did her doctoral research on rehabilitating and releasing captive dolphins.

“I was always interested in dolphin behaviour, but as I spent more time in the field, I became interested in applying what we learn about these animals to conservation questions,” Dr Waples said.

“The opportunity to work on a dolphin release came up and I jumped at the chance to return to Australia and participate in what was, at the time, a groundbreaking project.”

She described finishing her PhD and moving to Australia as a time when her career hit a crossroads.

“It became clear to me that to pursue a career in marine mammal field biology was not going to be easy or provide much in the way of job security.”

A move to wildlife conservation as a coordinator of wildlife management in New South Wales was ultimately a rewarding opportunity.

“I was responsible for coordinating and advising on a range of issues from nuisance flying foxes and possums to whale strandings and oil spills,” Dr Waples said.

“I was lucky to again have a career change when I returned to Perth and joined the Marine Science Program at DBCA.

“I have more of a science coordination role at WAMSI and have the opportunity to interact with a wide range of scientists from various disciplines to participate in research supporting conservation decisions and to advise on a number of marine mammal issues.”

In her role at WAMSI, Dr Waples is back working on a project involving her first research ‘love’- marine mammals.

“I’ve really enjoyed this last year with the opportunity, through the WAMSI Westport Marine Science Program, to be out in the field in our own backyard here in Perth learning more about the endangered Australian sea lions.”

“I’m learning new skills and working with a wide range of fantastic scientists, veterinarians and marine staff.”

Reflecting on International Women’s Day, Dr Waples said while most of her early mentors and colleagues were male scientists it had been heartening to see that change over time with many amazing and dedicated female scientists joining the ranks.

“I hope that I have done my part (improving the gender balance) by championing young female scientists where I can and giving them the advice and support to choose their paths well.”

Beach walkers invited to help penguin research

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A Western Australian Marine Science Institution project led by a scientist from The University of Western Australia is inviting people to help penguin research while getting fit.

Dr Belinda Cannell, from UWA’s Oceans Institute, said the project at Cockburn Sound was seeking volunteers who regularly walk at the beach to record any Little Penguins they find deceased.

She said her research over the past 30 years had shown many people were keen to help scientists and the community better understand the species.

“This will be the second year in a row the project has run, although volunteers also helped with similar research from 2007 to 2009,” Dr Cannell said.

“The feedback is people generally love to have an excuse to be out there doing some exercise, enjoying the environment and helping with important scientific research.”

Volunteers will be asked to walk a section of the Cockburn Sound foreshore, which has been divided into one-kilometre lengths, at least once a week for about a year.

Volunteers took part in more than 300 surveys last year but did not record any dead penguins.

Dr Cannell said the volunteer program was open to all members of the public, from citizen scientists and community groups, to corporate organisations and ocean lovers.

“If we find dead penguins we want to know what caused their deaths and see if there is a seasonal pattern,” Dr Cannell said.

“And importantly we want to identify strategies to protect the species.”

People who are interested in volunteering for the Little Penguin research project can email Dr Cannell here.

Cockburn Sound – home to a surprising diversity of marine species
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Scientists have found an unexpectedly diverse assemblage of marine life living on the seafloor in Cockburn Sound.

The species were identified following surveys of benthic communities in soft sediment and naturally occurring hard substrate as part of a research project that seeks to better understand benthic biodiversity and mitigate environmental impacts in the area.

The research team from the Western Australian Museum and Curtin University carried out a series of scuba-based visual surveys along the Kwinana Shelf, an area which had not been surveyed for some time.

At 12 sites sampled across two seasons, the researchers documented more than 2500 individual specimens on belt transects, including the hairy and porcelain crabs, worm snails, hammer oysters, blue ring octopus and the starry octopus, Octopus djinda, along with purple sponge barnacles, a range of urchins, sea cucumbers and sea stars, as well as eleven different species of scleractinian coral.

Thirty-five sponge species were identified, of which 21 have not previously been collected from Cockburn Sound.

Every individual animal encountered was identified in-situ or collected for identification in the laboratory. Work on the specimens is ongoing, but currently, more than 200 species across eight major marine invertebrate groups have been identified.

Dr Zoe Richards from the Western Australian Museum and Curtin University said “Derbal Nara (as Cockburn Sound is known to the Noongar people) is a nursery for pink snapper but what people might not realise is that one of the reasons the snapper aggregate and spawn there is because there is a huge variety of food sources in the Bay. Animals such as sponges, soft corals and tunicates form microhabitats for crustaceans, molluscs, worms and many other epifauna animals that the snapper prey upon”.

“The unexpected diversity and abundance of the smaller (<5 cm) marine animals has been critical to document in recent times, as this faunal component is vastly understudied on a global scale, an important aspect of food web ecology and consistently reveals species new to science” – Dr. Lisa Kirkendale, Western Australian Museum

Many of these specimens require genetic sequencing to confirm their identification and this is currently underway through the WA Museum’s Molecular Systematics Unit.

Additionally, the Museum has hosted Murdoch University and Edith Cowan University scientists have worked closely with Museum scientists to assist on site who are assisting with the processing of trawl samples that were collected in another phase of the project, and those samples will be used to assess the ecological values of the benthic community.

This research is being carried out under the WAMSI Westport Marine Science Program that will inform the development of Western Australia’s new container terminal.

Common construction materials trialled for future artificial reef

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Researchers from Murdoch University and Edith Cowan University are investigating materials for a future artificial reef in Cockburn Sound that will act as a settling area for local, non-invasive invertebrates.

The experiment, carried out under the WAMSI Westport Marine Science Program, is trialling four common construction materials (PVC, low-carbon concrete, natural limestone and mild steel) to understand which materials might be favoured by native marine species.

The material is cut into tiles and placed on aluminium frames called arrays then suspended in water.

As key stakeholders in Cockburn Sound, Austal Pty Ltd, Fremantle Ports, and CBH Group are facilitating this research by hosting eight of these arrays underneath their jetties, which will remain in place for a year.

Using this study design, the researchers can investigate what materials not only support the most diverse invertebrate community, but also what material may enhance coastal productivity by supporting the greatest number and biomass of invertebrates.

Historically, artificial reefs were first created unintentionally when ships were wrecked, for example Omeo in Coogee, but are now intentionally constructed as a way to enhance coastal aquatic ecosystems.

Early artificial reefs were built from surplus industrial product such as used car tyres and even whitegoods, however these materials were not favoured by reef-building species and sometimes leached harmful chemicals. They can also be exploited by invasive species that colonise areas rapidly and outcompete native fauna for resources.

Dr Sorcha Cronin-O’Reilly from Murdoch University’s Centre for Sustainable Aquatic Ecosystems and Henry Carrick from Edith Cowan University’s Centre for Marine Ecosystems Research note that it was important to determine the structural design and suitability of various materials of artificial reefs to replicate a naturally occurring biotic community.

“We expect many different invertebrates to settle, such as tunicates, sponges, and mussels, with more mobile invertebrates such as predatory sea slugs and marine worms to hide among these colonies.”

“Two weeks after deployment, we could already see some invertebrates had begun to inhabit the materials – showcasing the high demand for prime real estate, even in the ocean!”

As for which material may be most favoured by native invertebrates, it’s time to place your bets.

This research is also locally supported by Italia Stone Pty Ltd, Collie Crete, Plastral Pty Ltd, and CSM Fabrication.

CT scans to shed light on little penguin sensitivity to noise

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Researchers at Curtin University are determining the hearing sensitivity of a local penguin species to marine noise pollution.

The results could help determine to which anthropogenic noise frequencies little penguins (‘Fairy Penguin’) are most sensitive in the marine environment, with the aim of improving mitigation of noise pollution on local populations within Western Australia.

Sound pollution from shipping, near-shore construction, and other human activities can interfere with marine animals’ communication and increase stress levels.

Dr Chong Wei, a Forrest Research Fellow from Curtin’s Centre for Marine Science and Technology, is using sophisticated micro-CT imaging technology to create a computer model that can predict the hearing sensitivity of certain marine animals.

Computer simulations will be soon underway, with researchers using this model to study the sound reception process from the environment to the little penguin ear (i.e., outer, middle, and inner ear).

“Different noise sources have different characteristics, such as frequency. We want to know to which frequencies the penguins are most sensitive, and match these to known sounds in the marine environment – both human-made and natural,” said Dr Wei.

Little data currently exists on any penguin species’ sensitivity to sound, however insights from other diving bird species show a response to underwater noise.

Dr Wei said “Determining the noise sensitivity thresholds for endangered species and understudied species like little penguins is instrumental in determining which frequency of sound is most harmful and which anthropogenic noise may affect penguin populations and habitat.

“This will ensure improved conservation and mitigation strategies for the species.”

Weather station installed at Cockburn Sound

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Researchers from The University of Western Australia have installed a meteorological station at Cockburn Sound in the Cockburn Cement loading jetty to detect a range of atmospheric conditions that influence Cockburn Sound.

The weather station will be deployed for 12 months and measure wind speed and direction, air temperature, humidity, air pressure, solar radiation, precipitation and photosynthetically active radiation (PAR) at five-minute intervals.

This data will inform the analysis and interpretation of field measurements undertaken by different projects that include hydrodynamics and ecology.

Survey to assess value of recreational activities in Cockburn Sound

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A new project aims to identify the non-fishing activities in Cockburn Sound to assess the recreational use of the bay and the values it provides.

The University of Western Australia and Murdoch University are working with the Western Australian Marine Science Institution and the Westport Program on the two-year project to better understand how the area is accessed and used, provide economic valuation for key recreational sites, and help inform future development plans.

Dr Milena Kim, from UWA’s School of Agriculture and Environment, said Cockburn Sound was the most heavily used bay in Western Australia.

“It hosts a huge range of activities and is highly valued by many different users, including for many types of recreational activity,” Dr Kim said.

“While recreational fishing is an extremely important and well-known activity in Cockburn Sound, less is known about how and why the bay is used for other types of recreational activity.”

The research team is using an online mapping survey technique that asks the public to provide information about how and where they use the bay for recreation and the values people associate with the activities.

The survey will help inform future development by providing key data on recreational activity use, values, and spatial conflicts and how these may be influenced by further development in the bay.

Anyone who uses Cockburn Sound for recreational activities can participate. To take part click here or for more information contact socialvalues@wamsi.org.au.