Australia: Marine mammals under threat from climate change

Kerry Faulkner Science Network Western Australia 16 Aug 13;

CLIMATE change will threaten the survival of marine mammals according to researchers investigating the impact of rising air and sea surface temperatures on Australia’s ocean dwelling mammals.

They warn an increase in dugong mass-strandings could be among the consequences of climate change, in addition to reduced habitats and breeding success.

Their report, Impacts of climate change on Australian Marine Mammals appears in CSIRO’s Australian Journal of Zoology.

The research describes Australia as a ‘hotspot’ for marine mammals with 52 species. Two; the Australian sea lion and Burrunan Dolphin are endemic to Australia.

But it says air and sea surface temperatures around Australia have accelerated from the mid-20th Century and predictions are that the greatest rates of future sea surface temperatures warming will be in north-western and south-eastern Australia.

Deakin University’s Nicole Schumann says the most recent paper is based on CSIRO’s 2012 National Marine Report Card for Australia, which demonstrated climate change was having a significant impact on Australia’s marine ecosystem.

It is a synthesis of available information on the relationships between distribution and populations of marine animals and climate mediated oceanographic processes.

That information includes past WA research in into Shark Bay’s dugong and Ningaloo’s dolphin populations.

The paper says the potential for climate change to produce shifts in marine mammal distribution is of particular concern.

“As distributions shift the dynamics between species, for example competition for food resources, may change and populations may be exposed to new diseases to which they may have no resistance as they come into contact with populations they were previously isolated from,” Ms Schumann says.

In addition, shifting ocean currents like the East Australian Current and the west coast’s Leeuwin Current could reduce fish prey.

The research concludes the capacity of marine animals to survive may depend in part on their ability to alter their diet and foraging behaviours.

In addition, it says more research needs to be done to understand how marine mammals will adapt to climate change, their capacity to do so and whether some groups are more vulnerable than others.

“The important thing overall is to protect critical habitats though for many species, doing this requires more research into their ecology and habitats,” Ms Schumann says.