Disentangling the long-term effects of marine debris on Australian fur seals
The Penguin Foundation's purpose is to raise funds and receive grants to protect and enhance the natural environment of Phillip Island (Millowl). Phillip Island Nature Parks is delivering a 3 year project - 'Disentangling the long-term effects of marine debris on Australian fur seals' - in collaboration with Monash University and other partners. Seal Rocks is Australia's largest colony of Australian Fur Seals (AFS). Unfortunately, the location has high concentrations of plastic marine debris, owing to its proximity to popular commercial and recreational fishing locations and urban areas. At least 0.3% of seals in this area are entangled in marine debris, causing terrible injuries and contributing to a painful death; 69% of entanglements are in fishing gear. Sadly, only 50% of the affected population can be rescued.
Researchers and Marine Scientists from Phillip Island Nature Parks and Monash University are working collaboratively to explore the long-term impacts of marine debris on fur seals and to rescue and rehabilitate entangled seals. This work is made possible via funding from the Penguin Foundation, the Lord Mayor's Charitable Foundation Eldon and Anne Foote Trust Grant and a WIRES Research Grant.
The Phillip Island Nature Parks' conservation team is building knowledge about fur seals and to identify 'hot spot' entanglement locations and long-term impacts. This collaborative approach will improve capacity to rescue seals by developing better tools for identifying entanglement, such as testing thermal-imaging drones. New knowledge and data is being used to drive changes to Government regulations to better protect seals. Our teams are also working with FishCare Victoria on a community education and behaviour change campaign, targeting recreational fishing and wider community. Shared resources are being developed with Zoos Victoria, the University of Sydney and University of Melbourne, Victorian Fisheries Authority, DEECA, Parks Victoria, Bass Coast Shire and other stakeholders.
Fishing gear accounts for the majority of observed entanglements at Seal Rocks. It is extremely difficult to detect. Young seals are most affected, owing to their playful nature. As they grow, the entanglement tightens and causes terrible injuries which affect ability to feed, move and breed and contributes to a slow, painful death. There are major resourcing, logistical and safety challenges involved with rescuing entangled seals. Nature Parks is currently able to access and disentangle approximately 50% of observed entangled seals at Seal Rocks. There is a critical need to reduce the amount of recreational fishing debris around Seal Rocks and to improve capacity to 'see' entanglements (as fishing line entanglement is almost impossible to see via drone or from a boat). Robust research is needed to improve knowledge and support changes.
Work continues on the project looking at the long-term effects of entanglements on Australian fur seals. To date, we have successfully completed 42 drone surveys utilising state-of-the-art thermal sensors over Seal Rocks to see if this technology can be used for better entanglement detection. We have also taken samples from tracked five pairs of entangled and non-entangled fur seals during trips to Seal Rocks, to examine the effect of entanglement on health and behaviour of released seals. We are continuing to resight our previously tracked and released seals as well and have retrieved a tag and resight data from several entangled seals.
In a recent trip to Seal Rocks, marine scientists retrieved one tracker from an entangled and released seal that had been deployed in 2023 and three new trackers were deployed: one on an entangled and released pup and two on control fur seals that were healthy and unaffected by entanglement. The re-captured seal had its tag removed; it was recovering well and had grown in length and mass since last encountered.
Photo caption: Adam Yaney-Keller, Monash University PhD student (right) and Dr Rebecca McIntosh, Marine Scientist, Phillip Island Nature Parks, flying the drone to take thermal images off Little Gabo Island.