For Australian fur seals, impacts include ocean inundation of Seal Rocks breeding colony and changes to the food supply. Anthropogenic underwater noise is a known threat to marine mammals and disturbance caused by visitation can add further stress to a population facing threats from climate change. It is important to manage human impacts that are easily adjusted such as boat visitation, to improve their ability to adapt to a changing environment.
When we visit a fur seal colony, we typically think about what we see and what we smell. A fur seal colony can be a busy place, with the fur seals vocalising to each other, wrestling and playing. Now imagine what is happening underwater: the fur seals speed past your boat or roll around at the surface, they play with seaweed and turn somersaults. You may be surprised to learn that the fur seals vocalise underwater, groom and rest at the surface. They live in a complex world both above and below the surface of the ocean.
By placing underwater acoustic recorders in an array around Seal Rocks, research scientists examine the vocalisations of the seals and the level of vessel visitation through engine noise and characteristics (i.e. motor types, power levels and sound) and examine potential disturbance to the seals as a consequence of the visitation. The results will provide us with valuable data for future directions in marine spatial planning and inform best-practice ecotourism management. Generous funding of $20,000 from the Penguin Foundation and its supporters enabled the purchase of five hydrophones (sound recorders) to be utilised by the Phillip Island Nature Parks team and incorporated into a three year PhD project. An important benefit to this work will also be the recording of whale presence by their vocalisations and to develop methods to monitor cetacean use of the area. An acoustic array has large advantages over other methods for monitoring vessel use: they are low tech in that they can be deployed for long-periods of time compared to cameras; sound travels well in water, much better than light needed for cameras, therefore the data is more measurable and reliable; acoustic systems are a very efficient use of time, cost and energy resources compared to human observers and boat hours performing surveys.
This project will ensure greater protection for Australian fur seals, improved understanding of other key marine species including cetaceans, and facilitate management of marine mammals at the local, national and global level. When educating the public and providing ecotourism opportunities, we can be world leaders by operating under best practice that is guided by the best available science. This project will make a positive difference to Phillip Island’s marine environment. Through the results, we will be able to better protect the native marine wildlife and identify important marine habitats for protection and future funding opportunities.
Photo credit: Holly Baird Kina Diving
The Penguin Foundation amount: $20,000