A STUDY between the University of Sydney, National Measurement Institute and Phillip Island Nature Parks (PINP) showed startling evidence of high chemical concentrations in sea lions and local fur seals.
The research was primarily conducted by University of Sydney PhD candidate Shannon Taylor with research co-lead, senior lecturer Veterinary Pathology Dr Rachael Gray BVSc PhD, and assistance from PINP marine scientist Dr Rebecca McIntosh.
The team identified per- and polyfluoroalkyl substances (PFAS) in animals at multiple colonies in Victoria and South Australia over a three-year period, including at Seal Rocks off Phillip Island.
The study found PFAS concentrations in some animals were comparable to those in marine mammals in the northern hemisphere, including southern sea otters and harbour seals.
“When I started my PhD, PFAS was still emerging in Australia and had been previously identified in wildlife in the northern hemisphere,” Ms Taylor said.
“That was when I thought I would try to see what levels were in the seals, and after I looked into it, that’s when we were finding these high concentrations.
“I was wanting to look more into different age groups but unfortunately, that was quite logistically difficult, which is why we ended up focusing on the pups more so than all the animals, as well as that they are at a developmental stage vulnerable to effects of these chemicals, and our team is investigating impacts to health in pups.”
Ms Taylor said it was an incredibly lengthy project, as sample collection and lab work took time.
“It took about a year just to get everything through the lab and, from about halfway in 2019, I was working on the paper,” she said.
“Dr McIntosh and the team at PINP have been supportive of our work, which gave us the ability to get out to sample at Seal Rocks.
“It is also sadly very under-researched across Australia.
“There’s a lot of research in the northern hemisphere, but it’s hardly been touched on here.”
Living at Seal Rocks for up to a week at times, Ms Taylor said the location had been ideal for studying the fur seal colony there, as they believed the females forage in a region in proximity to Victorian PFAS sources.
She now hoped the research would help raise awareness and lead to the chemicals being banned in the state.
“It’s just concerning that they’ve got such high concentrations at that development stage, considering the health impacts identified in previous research,” she said.
“It’s difficult to do with the financial cost and logistics of getting to the islands and sampling the animals.
“There’s no toxic threshold in marine animals that’s been identified in previous research.
“We would like to pursue future research to see if there is immune suppression or developmental effects in these pups, and if we can find a link between concentrations of PFAS with death or disease.
“That would be the best step moving forward.”
Dr Rachael Gray and her team of scientists have also been conducting research in South Australia to try and save the endangered sea lion.
“One of the key focuses for us is the potential impact of these chemicals on the immune system which causes liver damage and neurotoxicity,” she said.
“We wanted to see if we could actually detect these concentrations in seals in Australia waters, and we sample pups predominately because we’re looking at the causes of mortality.
“For a long time, we didn’t do that kind of work because we thought surely pups have very low values or were non-detectable.
“But the absolute reverse was true.
“We found very high concentrations in these pups that are completely dependent on maternal input.”
Dr Gray said it was difficult to determine if the levels found could cause toxicity as it wasn’t fully understood how PFAS could affect the marine animals.
“They’re certainly of concern in terms of the impact they would have on development,” she said.
“We’ve worked collaboratively with PINP and Dr McIntosh to get the logistical and intellectual support to get out to Seal Rocks.
“There was a bit of variation in the concentrations among the animals but there were some high ones.
“PFAS is not easily or if ever degradable in the environment.
“Sea lions and fur seal adults bio-accumulate the highest concentration, and what we know is one of the ways the mothers get rid of their loads is offloading to their pups through gestation and lactation.
“The pup who is in the fundamental development stage… they’ve got this chemical present that could be depressing development.”
Dr McIntosh said the project had been great to be a part of as it fitted with PINP’s strategy to monitor the Seal Rocks’ colony.
“Part of our plan was to do that kind of research, so we joined ranks and helped with some of the fieldwork in facilitating the research team and students out there,” Dr McIntosh said.
“We’re doing it for conservation and to protect biodiversity, the fur seals are what we call an ecosystem sentinel.
“They’re at the top of the chain in this area and if they’re doing really well, then the ecosystem underneath them is healthy.
“But if something is going wrong with them, it’s in the food chain and it’s potentially in our food.
“We haven’t made that link yet, it’s just a first step in the process, but that would be how they’re getting it through what they’re eating.”
Dr McIntosh said the organisation hoped to receive more funding to continue monitoring the animals and further establish how the chemicals were affecting them.
“An increasing number of pups don’t make it before full term,” she said.
“Every time I go out every two months, I notice there are some foetuses in the colony and I’ve noticed that’s increasing in the last several years.”