The combined effect of rapid ocean warming and the practice of targeting big fish is affecting the viability of wild populations and global fish stock says new research by the University of Melbourne and the University of Tasmania.
Unlike earlier studies that traditionally considered fishing and climate in isolation, the research found that ocean warming and fishing combined to impact on fish recruitment, and that this took four generations to manifest.
"We found a strong decline in recruitment (the process of getting new young fish into a population) in all populations that had been exposed to warming, and this effect was highest where all the largest individuals were fished out,” said lead author and PhD candidate, Henry Wootton, from the University of Melbourne.
Mr Wootton and his team established 18 independent populations of fish in their lab and exposed these to either control or elevated temperatures, and to one of three fisheries harvest regimes. They then followed the fate of each population for seven generations, which equates to nearly three years of lab time. “Our study is the first to experimentally explore the joint impact of fishing and ocean warming on fish populations,” Mr Wootton said.
Read more at University of Melbourne
Image: Rapid ocean warming and the practice of targeting big fish is affecting the viability of wild populations and global fish stock (Credit: Harrison Haines)