The world’s oceans have the potential to be significantly more plentiful, even with climate change, if sustainable fisheries management practices are put in place.
A new study published in the journal Science Advances, shows that if the world meets the Paris Climate Accord, by ensuring global temperatures don’t rise above 2 degrees Celsius, there will be 25 billion additional servings of seafood and 217 million more metric tonnes of fish in the sea, or nearly a third more fish than exist today.
However, fisheries management that addresses climate change and its effect on the productivity of species and geographical range distribution will need to be implemented.
“If we can adopt sustainable fishing policies and keep global warming at no more than two degrees Celsius, we can realise significant benefits to fisheries across the globe. But these benefits require action. Governments must change the way fishing takes place or risk losing a crucial opportunity to secure food supply,” said study author Merrick Burden.
Researchers examined potential future outcomes for 915 fish stocks across the world. They modelled the impact of climate change on fishery productivity and geographical range distribution, which affects how many fish are available and where they can be caught, under four climate projections, ranging from a global temperature rise of 1 degree Celsius (strong climate mitigation) to a rise of 4 degrees Celsius by 2100 (business as usual).
For each scenario, researchers examined future biomass, harvest and profit using different fisheries management approaches.
Roughly half of species examined will shift across national boundaries and nearly all will experience changes in productivity in response to rising ocean temperatures.
However, if fisheries management practices are implemented to mitigate effects of climate change on productivity and geographic range distribution, there will be gains in biomass, harvests and profits. The practices include multilateral fishery agreements and responsible harvest policies that account for changing stock productivity.
Nevertheless, future fisheries profits will decline in developing countries even with management that fully adapts to climate challenges.
“Even with the right management changes, there will be winners and losers. Success will require not only emissions reductions, but also multilateral cooperation and real changes in fisheries management. With growing global population and the increasing needs for healthy sources of protein, these changes will be critical,” said Steve Gaines, the study’s lead author.
Many people rely on fish for protein, and 845 million people face serious malnutrition worldwide, partly due to poorly managed fisheries.
If nothing changes, 80 per cent of the world’s fisheries will be in serious trouble by 2030. Most fishing nations are not responding fast enough to create change and successful transboundary management programmes are relatively rare.
Action doesn’t take long to have an impact on some species. Studies have demonstrated that many fisheries can bounce back from overfishing in as little as 10 years’ time under the right policies.
“Climate change is expected to hit hardest in many of the places where fisheries are already poorly managed – things are likely to get a lot worse if we don’t act,” said Christopher Costello, an author of the paper.
“We can expect inaction to bring increased conflict and potential overfishing as fish move into new waters along with threats to food security in some of the world’s most vulnerable places.”- Science Daily