CSIRO scientists are studying the impacts of climate change on seabirds and marine mammals, and investigating options to help them adapt to future change
While quite a lot is already known about the impact of climate change on seaweed, shellfish and fish, less is known about the impact on seabirds and seals. It is critical that this knowledge gap is addressed.
Dr Alistair Hobday, the Leader of the CSIRO’s Marine Climate Impacts and Adaptation Stream, says seabird, whale and seal watching are important for Australian tourism.
“Little penguins at Phillip Island, for example, are an iconic Australian tourism site. Understanding how those species will be impacted by a warming ocean is important part of conservation,” he says.
But it remains unclear how seabirds and marine mammals will respond to warming waters, because they typically breed in colonies in fixed locations. Through the monitoring that has already been taking place in Australia, it has become apparent that some species characteristics are better to monitor than others. This includes how long animals spend foraging at sea, away from colonies.
CSIRO are using tools such as high-resolution remote cameras that record information such as where nests are located, the presence of eggs and chicks, and when an animal arrives at a nest and leaves.
“As an ocean becomes less productive under climate change, those foraging trips may become longer,” says Dr Hobday. “As the foraging trips become longer, the seabirds will bring less food back to their chicks and we may see decreases in chick survival.”
Australia harvested seals, seabirds and other marine mammals up until the 1970s. Many of those species are now under threat.
“If those species start to suffer climate impacts we may modify the way in which we do tourism,” Dr Hobday says. “For example, boats might be asked to stay a greater distance away from colonies so they don’t disturb animals and result in extra energy use.”
Some impacts are already evident. Australia’s oceans are warming at a rate four times the global average, particularly in the south east and south west of the country. Many species are sensitive to warming waters. As a consequence, they are changing their behaviour.
On Australia’s east coast, some 45 species of fish have moved further south. For others, there are impacts on their breeding success, or the time of year in which they begin breeding.
How else can we help these vulnerable creatures?
The Victorian heatwaves of the past couple of years had a devastating impact – and not just on people. Penguins struggled to cope with the many days over 40 degrees. Some of them died.
“Penguins can’t pant like a dog and so once the temperature gets too warm they just suffer water loss and can die,” Dr Hobday says.
Conservation managers have been looking at ways to cool these birds when they are on land. This includes planting vegetation around nesting boxes, to help the penguins cool down. Another strategy is burying these boxes under sand, so that the ground insulates them and the penguins don’t overheat.
Seals are also vulnerable. As they spend more time trying to cool themselves in the water, they spend less time with their baby pups. As a consequence, they may feed their pups less.
“Maybe we can investigate interventions – almost like a Jacuzzi for seals on their breeding colonies – so they can get into the water, cool off, and then get back to their pups very quickly,” Dr Hobday says.
Other strategies include weed management and protecting burrows from flooding. Some species may even have to be moved from an area that has become unfavourable to a new one.
All hands on deck
There has been a belief that all we can do to help seabirds and marine mammals respond to climate change is to ensure they have enough to eat, and reduce other pressures they’re experiencing. However, by sharing knowledge with others, we can devise more solutions to explore in coming years. This includes supplemental feeding, disease treatment and building artificial nests for seabirds – all things that could help provide more protection against climate change.
“Increasingly our research is less about a scientist sitting at his desk doing programming or data analysis,” Dr Hobday says.
CSIRO scientists are working in the community with people like fishermen, marine park managers, and conservation managers for seabird and marine mammal colonies. By working collaboratively, we can learn about what has been tried and failed. And we can carefully test other strategies together.