A Garden Island penguin and her chicks.
A UNIVERSITY researcher with more than 16 years’ experience of Little Penguin colonies on Penguin and Garden islands says the proposed Mangles Bay marina has the potential to increase boat strike of the protected marine birds.
Belinda Cannell, a postdoctoral research fellow at Murdoch University’s centre for fish and fisheries research, said the world’s western-most colonies of Little Penguins was extremely fragile.
She intends to make a submission to the marina’s Cedar Woods public environmental review, which states the development could potentially disturb the colonies and cause an increase in boat strike of marine fauna, in particular Little Penguins.
Dr Cannell said about 20 per cent of dead penguins found by her team were a result of boat strike.
A stark example of the fragility of the islands’ colonies was Penguin Island’s lower-than-usual population estimate coinciding with last summer’s marine heatwave caused by one of the strongest La Nina events ever recorded.
It increased local sea temperatures by about 5C.
“Penguins won’t attempt to breed in years when there’s not enough food and last year was the worst breeding season I’ve seen since 1996,” Dr Cannell said.
She said it was also the worst since 1986 when collection of breeding data began.
“Only about a third of the normal amount of eggs were laid and this will have an effect on the population later on,” she said.
“We don’t have enough scientific data to show where the Garden Island birds feed but it’s likely to be on anchovy and pilchard in that southern area of Mangles Bay and the reduction in seagrass there, increased boat activity and pollutants in the water is unpredictable.
“It could also affect their feed stocks in an area that is a nursery for the types of fish they feed on.”
Dr Cannell said while she had some funding to fit some Garden Island birds with GPS tags from mid-year, more funds were needed to complete ongoing studies.