Fur seals return to the Five Islands

Australian fur seals on Martin Island (photo credit: Paul Jones)

The University of Wollongong is working with the National Parks and Wildlife Service in the Five Islands Nature Reserve, with students flying drones over Martin Island to get a picture of how many Australian and New Zealand fur seals live there.

As Associate Professor Sarah Hamylton and Dr Rowena Morris motor passed tugboats and iron ore ships, plumes of white smoke rise from blackened chimneys. Just over a kilometre from Port Kembla’s steel works and directly offshore from the sewage treatment plant is a setting that would rival any David Attenborough documentary.

Hamylton edges the research boat to a spot protected from the wind and swell at the edge of the island “The first time Rowena took me to the islands, I was blown away by the wildlife there” she recalls “the noise of the birds is overwhelming, you have to watch where you walk on every step as nests full of bird eggs and live babies literally cover the floor… it was such a surprise given the industrial setting”

Keen to show off their water skills, younger seals slide gracefully into the water, effortlessly appearing suddenly at the side of the boat. Australia’s fur seal population dramatically reduced between 1798 and 1923 due to commercial sealing. The species is still threatened by fishing, plastic pollution, entanglement and oil spills. As recently as within the last ten years, there are stories of frustrated fishermen pulling out rifles and shooting the seals who were stealing their catch. The marine mammals are now protected, and are increasingly spotted along the beaches of the Illawarra and nearshore islands.

This is a classic study site where drones provide a practical solution.  The recent return of seals to Martin Island demands our attention, but the jagged rocks drop straight down into crashing waves. Landing on the island is very difficult so without direct access, we use the drone to capture quick and continuous high-resolution photos across the whole island. The photos are then stitched together to create a mosaic, from which we can reliably count the seals.

Our year-long study found that the seals at Martin Island preferred cooler winter waters, increasing from a few individuals in March to a peak of approximately 103 seals in late July. The study provides some of the first ever research on fur seal behaviour at Martin Island and will guide conservation of the seals here.

Note: it is illegal to land on the Five Islands, or fly a drone within 100 m of marine mammals.