Biodiversity will be the key to keeping global fisheries going as sea temperatures rise, the prestigious Smithsonian Institution has found in a study backed by Tasmanian-driven citizen science.
The latest global analysis of the challenges faced by fisheries was led by the US-based Smithsonian but based on data provided by the Reef Life Survey a Tasmanian initiative which co-ordinates citizen science conducted by volunteer divers from 10 countries.
This study is based on more than 4500 underwater surveys, said Reef Life Survey co-leader Rick Stuart-Smith, from the University of Tasmania’s Institute for Marine and Antarctic Studies.
Scientists have long been troubled by the accelerating loss and rearrangement of species as oceans warm, and the idea that biodiversity can offer practical value in combating this has been controversial.
But the Smithsonian study, published in Proceedings of the National Academy of Sciences, confirmed that biodiversity was a key factor needed for fish resources to thrive in coming decades as communities with more fish species are more productive and more resilient to both rising temperatures and temperature swings.
Preserving biodiversity is not just an aesthetic or spiritual issue it’s critical to the healthy functioning of ecosystems and the important services they provide to humans, such as seafood, said lead author Emmett Duffy.
But a separate Swedish-led study involving UTAS research fellow Timothy Clark found that while fish could adapt to slowly rising temperatures, they could only adapt so far.
Dr Clark said ever-increasing water temperatures and added stresses such as heatwaves could be catastrophic.
Dr Clark’s project compares European perch in the Baltic Sea with examples living in a lake that has been heated by water from a nuclear power plant, making it 5 to 10 degrees Celcius warmer.
There’s been a lot of speculation about what fish populations will look like in 100 years, but this is the best evidence to date that fish are not going to be able to adjust indefinitely which is why we have to manage greenhouse gas emissions and try to limit global temperature increases, he said.
There’s already issues facing aquaculture, for example growing salmon, where the animals are not doing as well in the summer months.
News Corp 2016