Posted on 06/05/2021 by

Uncovering the secrets of Australia’s fur seals – from above and below


Researchers at Phillip Island Nature Parks are beginning to unlock some of the secrets of the world’s largest colony of fur seals off Phillip Island through the use of both aerial and underwater technology.

The popular SealSpotter Challenge which launches on Sunday 9 May, gives participants the chance to contribute to vital research by monitoring the seal population via thousands of high-resolution images, captured by drones, and uploaded to the SealSpotter web portal.

These images are from the recent breeding and pupping season at two fur seal colonies, Seal Rocks and The Skerries, located on Victoria’s off-shore islands.

“Anyone with a device can help by counting adults, juveniles, and pups right through to the end of May in this important collaboration between citizen scientists and researchers,” says Dr Rebecca McIntosh, Research Scientist with Phillip Island Nature Parks.

“Participants can also help to spot individuals that are entangled in nets, fishing line and plastics from the ocean, across both locations.”

“We are finding some very interesting results, and beginning to uncover some of the secrets of the world’s largest colony of Australian fur seals, right here on our doorstep at Seal Rocks off the coast of Phillip Island.”

“Comparing the Seal Rocks colony, where over 3,000 pups may be born every year, with a remote and private colony such as at The Skerries near Mallacoota will help us understand more about these amazing animals and how they respond to the world they are sharing with all of us.”

“The contribution made by citizen scientists is really important to us, and although on occasions it can be confronting when viewing images that include dead seal pups, the information collected is incredibly valuable. Fur seal breeding colonies are dynamic and busy places and not all pups that are born survive to become adults.”

During last year’s SealSpotter Challenge, citizen scientists from over 37 countries across every continent, managed to view and label over 14,289 images and classify over 281,197 seals. Four collaborators each completed the full set of1939 images, which is an amazing effort and fantastic for statistically reliable results.

Researchers have also ventured underwater in an effort to measure and understand the impacts of underwater noise on this important breeding colony of seals. Commercial divers braved the surging swells at Seal Rocks recently to install a hydrophone which will detect underwater noise 24 hours per day for up to a month on just one battery.

The hydrophone is part of a new PhD being performed by Jessalyn Taylor from the Sydney School of Veterinary Science at the University of Sydney, investigating if vessels that visit Seal Rocks cause any disturbance to the seals, particularly during the breeding season (Nov-Dec) when newborn pups are weak and vulnerable.

The hydrophone project is supervised by an international and cross-disciplinary team made up of Dr Rebecca McIntosh, Dr Rachael Gray from the University of Sydney and Dr Isabelle Charrier from the University of Paris-Saclay & CNRS.

“It was challenging to install equipment underwater with waves crashing overhead, and seals are pulling at the divers’ fins and oxygen source. They are so curious and playful. When observing how the seals play with the hookah cable, it is easy to see how they become entangled in marine debris and fishing line.”

Regulations are in place to protect marine mammals both from above and in the water. Recreational boats, kayaks and paddle boards need to stay 60m away from the low water mark at Seal Rocks to minimise disturbance and entanglement in recreational fishing line. Jet skis are prohibited vessels and need to stay 260m away from the low water mark. Permitted tour vessels may approach to 30m from Seal Rocks.

Drones cannot approach within 500 vertical metres or within a 500-metre radius of a whale, dolphin, or seal. Nature Parks’ researchers have undergone rigorous training and certification, and fly these research drones under permit.

The SealSpotter portal was developed by Phillip Island Nature Parks’ researchers thanks to generous funding from the Penguin Foundation.