WAMSI offering two free student registrations for lobster biology conference

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The Western Australian Marine Science Institution is offering two WA-based Honours, Masters or PhD students the chance to improve their understanding of rock lobster and crab biology with free registration for the International Conference and Workshop on Lobster Biology and Management (ICWL) in Fremantle this October.

The theme of the 12th ICWL is ‘Ecosystem-based fisheries management (EBFM)’ – an approach that recognises all interactions within an ecosystem rather than considering a single species or issue in isolation.

WAMSI is a Bronze Sponsor of the conference and has secured two student registrations to offer people undertaking study at any of our partner universities (Curtin University, Edith Cowan University, Murdoch University and The University of Western Australia) or working at our partner organisations while doing further studies. They must be WA based but can be enrolled at other universities.

WAMSI Research Director Dr Jenny Shaw said it was an opportunity for students to find out more about marine research and fisheries and explore career opportunities.

“The ICWL began in Perth more than 40 years ago. At the time, 37 biologists from six countries met to discuss and compare their work on a range of lobster topics,” Dr Shaw said.

“Since then, it has grown in popularity and prestige.”

“Given the WA rock lobster fishery is the largest single species fishery in Australia with a value of more than $450m annually and was the first in the world to achieve Marine Stewardship Council accreditation, this is a fabulous opportunity for students to learn more about the industry as well as science around the species.

“It’s also a terrific opportunity to network at a prestigious, international conference.”

Students who are interested in applying for WAMSI’s student registration offer are asked to:

Write a letter (maximum of one page) outlining their area of study, explaining how they would benefit from attending the conference and stating where they are enrolled.

Applications should be addressed to Dr Jenny Shaw and be emailed to info@wamsi.org.au by 5.00pm on Monday 4 September 2023. A decision will be made on Monday 18 September.

Details about the conference can be found here.

Study of 1921 Shark Bay cyclone sheds light on present dangers

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A historical account of fish being stranded up to nine kilometres inland by a cyclone in Shark Bay a century ago has been used with numerical modelling to help assess current risks from extreme weather to areas on the edge of tropical cyclone zones.

The cyclone struck the area, 750km north of Perth, in 1921 killing two people, flooding the shores of the outer gulf and causing extensive harm to the pearling industry, seagrass meadows and freshwater wells which remained saline for decades.

The research paper, The utility of historical records for hazard analysis in an area of marginal cyclone influence published in Communications Earth and Environment, reconstructed the cyclone partly through extensive surveys of State and national archives including accounts by a pearling inspector. It also involved using a groundbreaking approach, Quantified Historical Data Framework, to do a structured analysis of archival information to evaluate the authenticity, consistency and relevance of reports of the extreme weather event.

Dr Jenny Shaw, Research Director for the Western Australian Marine Science Institution, worked on the paper in collaboration with researchers from the Nanyang Technological University in Singapore, The University of Western Australia, University of Sydney, Griffith University, Baird Australia and Minderoo Foundation.

Lead author Associate Professor Adam Switzer from Nanyang Technological University’s Earth Observatory of Singapore said the study engaged a diverse team of historians, geoscientists, marine biologists and engineers, showing the need for multidisciplinary collaboration to tackle complex issues such as the risks of cyclones and storm surges in a warming world.

The study noted tropical cyclones were likely to shift poleward in a warming climate and some researchers had suggested the trend was particularly obvious in the Southern Hemisphere.

“This approach provides researchers worldwide with a valuable framework for leveraging historical documents to derive actionable modeling parameters, benefiting areas that face similar challenges,” Associate Professor Switzer said.

Dr Shaw said the study of the cyclone, which struck what is now a World Heritage site, found it had a major ecological impact in a similar way to TC Yasi in Queensland in 2011.

“A recurrence would likely have considerable long-term knock-on effects to ecosystem functions and services, particularly as the seagrasses of Shark Bay contribute to several World Heritage values,” Dr Shaw said.

One of the accounts of the cyclone, found during a search of archives, was by Pearling Inspector Wally Edwards, who witnessed the cyclone and its aftermath.

He described seeing ship groundings, inundated coastal wells, flooding, an altered coastal landscape and sharks and fish stranded inland.

Longer term impacts included livestock losses, declines in the shells used in the pearling industry and reports that dugongs were seen less frequently in the years after the cyclone.

The researchers said a similar cyclone, assessed to be between a category four and five, would inundate the town of Denham flooding critical infrastructure and damaging important industries.

Dr Joseph Christensen, from UWA’s School of Humanities, said the study uncovered detailed information about the historic event.

“By employing the Quantified Historical Data Framework, we were able to establish a detailed and quantified understanding of the 1921 storm surge, including its timing, nature and ecological consequences,” Dr Christensen said.

The authors said the approach had important implications for land use planning, emergency management and environmental management of Shark Bay and other sites of marginal cyclone influence.

Seagrass put to test to find best species for withstanding climate change impact

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Researchers looking at the possible impact of climate change on seagrass have tested the tolerance of the plants to rising temperatures after collecting samples at locations spanning 600 kilometres.

Nicole Said, a research associate from Edith Cowan University who is part of the WAMSI Westport Marine Science Program project, said six seagrass species were collected within Cockburn Sound and one, Posidonia sinuosa was collected along Western Australia’s coast from Geraldton to Geographe Bay.

The samples, which represent species that are all found in Cockburn Sound, were then put in chambers and subjected to incremental increases in water temperature from 15 to 43 degrees over 12-hours.

Oxygen changes in the water were measured to calculate the plant’s photosynthetic rate or the rate at which light energy was converted into chemical energy during photosynthesis. The experiments allowed researchers to understand at what temperature the plants thrived or were stressed.

“It appears from the species that we looked at in Cockburn Sound, the one most at risk from rising temperatures was Zostera nigricaulis which is commonly known as eel grass,” Ms Said stated.

Halophila ovalis, a species found in temperate to tropical areas and commonly known as paddle weed, spoon grass or dugong grass, was most able to withstand the higher temperatures.

Other species tested were Amphibolis griffithii, Posidonia sinuosa (the most widespread species in Cockburn Sound), Posidonia australis and Amphibolis antarctica, which are larger plants than the other two species assessed.

The research team found a heatwave in Perth that produced temperatures between three and four degrees higher than average summer temperatures would be likely to have a negative impact on the larger species which are generally able to withstand pressures for a greater duration than smaller species, but once damaged take longer to recover.

Heatwaves are predicted to become more frequent and more intense under climate change. An extreme marine heatwave in 2010 and 2011 saw a large area of seagrass in Shark Bay destroyed.

“With increasing ocean temperatures and an increase in marine heatwave events, seagrass species living close to their thermal limits are at risk from rising temperatures. There is limited temperature threshold information for seagrass species, which is critical information and can forewarn both present and future vulnerability to ocean warming.”

“There are other researchers around the world looking at climate resilience, but we have been missing this key baseline data to look at the physiology of seagrasses and how they may respond to these climate scenarios.”

ECU School of Science Associate Professor Kathryn McMahon, who co-leads the research on seagrass resilience said the findings were significant.

“These findings are really exciting as they indicate there are differences among seagrass species and population along our WA coast to ocean warming,” Associate Professor McMahon said.

“We can harness these differences and take actions to try and build resilience into our spectacular seagrass meadows.”

From sonar to drones: Fishing around for best research results

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Researchers are using everything from sonar and baited cameras to traps and drones as part of a project looking at the distribution and abundance of key fishes and invertebrates in Cockburn Sound.

The Department of Primary Industries and Regional Development’s Dr Danielle Johnston, who is research lead on the project, said a wide range of methods were being used to monitor larvae, juveniles and adults of commercially, recreationally and ecologically important species. They were being sampled in various habitats and depths.

“February this year marked the end of 18 months of field work which included 220 days sampling with more than 300,000 individual fish and invertebrates identified, representing 244 taxa from 88 families,” Dr Johnston said.

She said using many methods for monitoring and assessing distribution of various species meant researchers needed to spend a lot of time in the field.

”Spring 2022 was the busiest field season to date, with 56 days of sampling, including intensive spawning biomass and larval surveys for snapper and blue swimmer crab.”

DPIRD Scientist Dr Daniel Yeoh, who is part of the WAMSI Westport Marine Science Program team and coordinating field surveys for the project, said drones were being tested to determine if they could be used for surveying changes in abundance of snapper in spawning aggregations.

“Snapper are a bigger fish and can form very dense schools near the surface, so we’re trialing drone surveys to see if we can survey them from the air.”

Sonar was proving useful for detecting schools of snapper further below the surface and the technology was also being used to study schools of smaller forage or bait fish such as sardines and anchovy.

“The acoustics work is being done in collaboration with a CSIRO team in Hobart who are leaders in these acoustic surveys.”

“There are five main species of bait fishes we are looking at including pilchards or sardines and scaly mackerel.”

He said while recreational fishers were sometimes less interested in bait fishes, they were a crucial part of Cockburn Sound’s ecology.

“Some of these species are caught for human consumption or bait, but they are particularly important as prey for penguins and dolphins and we have been providing other researchers with samples and data to use in their projects,” Dr Yeoh said.

“We are looking at what species of fish are found in Cockburn Sound and how their abundance and distribution changes throughout the year.”

“We’re also checking key water quality parameters such as temperature, salinity, dissolved oxygen and turbidity during most of our sampling.”

He said baited remote underwater video stations, which provided researchers with a close-up look at fish, will be put out at more than 150 locations this winter.

“The BRUVs are designed to spot juvenile snapper which were spawned during the last spring,” Dr Yeoh said.

“They grow throughout the year and by winter we can see them on the cameras.”

The project is a collaboration between the Department of Primary Industries and Regional Development, Murdoch University, Curtin University, Edith Cowan University and CSIRO.

Studying the sizes, seasons and whereabouts of Cockburn Sound’s squid

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Innovative research in Cockburn Sound is looking at the distribution, abundance and seasonal habits of squid – a popular catch for recreational fishers.

The project is part of the WAMSI Westport Marine Science Program and designed to better understand the population of squid in the area. It is one of the first projects in Australia to try to determine localised habits of southern calamari – the main squid species in Cockburn Sound.

Dr Daniel Yeoh from the Department of Primary Industries and Regional Development, who is part of the research team, said scientists had been doing monthly sampling at up to 30 sites from Fremantle to Rockingham.

“We are looking at which areas of the Sound are most important to squid, including specific habitats and depth,” Dr Yeoh said.

“Certain habitats like seagrass generally have higher catch rates than bare sand.”

He said the exact location and depth of every squid caught was recorded using a GPS. Squid were then quickly measured and their sex noted before being released. A range of environmental parameters were recorded on each sampling occasion, including temperature, water clarity, weather and sea conditions.

“Scientists are finding out what factors influence the distribution and abundance of squid and how this is affected by environmental conditions such as temperature and water clarity. A range of biological information has also been gathered to improve the understanding of squid life cycles in Cockburn Sound,” Dr Yeoh said.

The sites selected for sampling ranged in depth from two to 15 metres and contained areas with dense seagrass meadows, areas with sparse seagrass coverage, and sandy areas with little or no vegetative cover.

“Studies in the eastern states have shown certain species of seagrass are more important for breeding and squid to lay their eggs on, so not all seagrass is the same.”

He said the research was ongoing but there were seasonal trends emerging.

“We started this research in August 2021 and the catches were moderate and then they declined in spring and summer. By the next autumn, catch rates increased.”

“Squid have a very short life cycle and only live for about one year. Their peak spawning is during spring when the large adult squid lay eggs and then die-off.

“Over summer the young squid grow and by the following autumn they reach a size where they can be caught, so catches increase.”

Dr Yeoh said most of the squid caught by the researchers were released but they were initially kept in holding tanks on the research vessels.

“Because we don’t want to catch the same squid twice, we put them in an aerated holding tank and we have found they release well. They don’t tend to release well if they’re kept in a bucket.”

 

 

Data team collecting, checking and delving into historical records

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While dozens of scientists working at Cockburn Sound are busy with field trips and laboratory work, a team behind the scenes is occupied with managing huge amounts of research data while also uncovering and collating crucial historical data to feed back to the projects.

Dr Alicia Sutton, who is part of the Western Australian Marine Science Institution Location Data Management Services team, said its role was to help with quality control on current data collection and locate historical scientific information to support the WAMSI Westport Marine Science Program’s 30 projects.

“With historical data, we collate data from as far back as possible,” Dr Sutton said.

“One source of data has come from seagrass monitoring which has been collected by the Cockburn Sound Management Council for many years. This data has been provided to WAMSI researchers looking at seagrass in the Sound to provide context and allow for comparisons.”

Another example is collating data on beach profiles (measurements of the angles of the shoreline to look at variability in topography and slope) previously collected by local and State Government, which WAMSI researchers are using to understand shoreline movement across time.

“Water quality data has also been collated across industry and government bodies to help inform a water quality response model for Cockburn Sound as part of the WAMSI Westport Marine Science Program.”

Dr Sutton said collecting historical data had been challenging but it would have benefits beyond the current science program.

“In the case of data collected during the WAMSI Westport Marine Science Program, data will become publicly available and be accessible for the long term.”

“That is going to be really helpful for future projects and will allow researchers and other stakeholders to access relevant data easily, without having to contact multiple organisations and trawl through large volumes of reports,” Dr Sutton said.

The range of the data coming in from the projects of the WAMSI Westport Marine Science Program is broad. It includes spatially mapped data, photos and video footage, models, acoustic spectrograms, social surveys, laboratory and field experimental studies, biological surveys and more.

The data from the current science program, when combined with other available government and industry data has the potential to support the development of regionally specific products and science outcomes, including hydrodynamic and sediment transport models and integrated marine ecosystem biogeochemistry and ecological models.

Managing the data and keeping it safe is a big task.

Data is stored on a collaborative but secure WAMSI storage space as well as at the Pawsey Super Computing Research Centre.

Thousands of creatures uncovered in sediment samples

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Sediment sampling by scientists in Cockburn Sound and Owen Anchorage has uncovered thousands of tiny marine animals and more than 200 unique species.

Researchers from Edith Cowan University, Murdoch University and Western Australian Museum found the animals, known as benthic invertebrates, living in and on top of sediment in 30 sites.

Professor Glenn Hyndes, from ECU, said the sediments were collected across two seasons using a Van Veen Grab Sampler which was operated on a boat to scoop up sediment.

“Sorting and species identification is continuing but at the moment more than 17,000 individuals from eight major invertebrate groups have been found.”

“Sediments from the sites were sieved to remove fine mud which left behind coarse sediment along with the animals,” Professor Hyndes said.

“During hundreds of hours work we found animals such as adult worms, snails, crustaceans, urchins and bivalves which ranged from one to five millimetres in size,” he said.

“We used tablespoons to locate and separate often fragile animals from the sediment.

“Taxonomists at WA Museum have been working constantly to identify the species, characterising the hidden diversity of this urban seafloor habitat.”

He said invertebrates were important because they played a significant role in healthy ecosystems as food for commercially important species, burrowers of sediment and by using multiple life strategies such as parasitism on bigger animals.

“This is the first benthic survey targeting invertebrates to be carried out at this scale in the Cockburn Sound area and the sheer quantity and diversity of invertebrates has been an interesting and exciting discovery.

“The data produced from this work will tie into similar projects focused on the abundance, diversity, distribution and diets of larger animals in Cockburn Sound and the ecosystem of which they are an important part.”

Professor Hyndes is working on the project, conducted under the WAMSI Westport Marine Science Program, with Dr James Tweedley and Dr Sorcha Cronin-O’Reilly from MU, Henry Carrick and Leah Beltran from ECU, along with, Dr Peter Middelfart from WAM, Dr Lisa Kirkendale, Dr Andrew Hosie, Associate Professor Zoe Richards, Oliver Gomez and Ana Hara.

As part of the project, researchers are also investigating the settlement of species on different hard substrates and under different conditions and locations. This project forms part of the WAMSI Westport Marine Science Program and understanding how to improve the effectiveness of substrate in a concentrated area will help develop successful, large-scale initiatives.

 

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.