Climate change will upend our ocean, but we can overcome it

| 26th September 2018
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The oceans can generate more abundant fish populations, food for human consumption and profits for fisheries. But nations must act now to adopt fisheries management reforms that take a changing climate into account, argues KRISTIN KLEISNER

Decades of research and real-world examples have shown that our oceans can be incredibly resilient with good fisheries management.

The headlines are true. We are already facing, and will continue to face, some severe changes to our environment, including our oceans, as a result of climate change. But if we act now with proactive and adaptive good management, there may be a chance to see better outcomes. 

I was the co-author of a study recently published in Science Advances showing that climate change-induced warming of our oceans will alter the productivity and movement of global fish stocks. As ocean temperatures rise, fish populations will travel outside of their normal ranges, largely shifting towards the poles.

In Europe, the impacts of climate change on commercially vital fish species are already visible, with recent research indicating that 16 out of 21 of the most valuable fish species in the North-East Atlantic inhabit waters outside of where they have traditionally been found. Of these 16, nine are considered ‘big movers’ – with those nine species representing more than 50 percent of the landed value of the North-East Atlantic catch.

Unless we prepare for these types of changes, they will wreak havoc on a global fishing system that is already under stress from overfishing, and unprepared for the impacts of shifting fish populations.  

Ocean productivity                                                      

Importantly, our latest research outlines an opportunity to improve on the picture of ocean health and marine food production that we see today.

If more nations begin to manage fishing sustainably, work together on shifting stocks, and establish policies that limit warming to no more than 2 degrees Celsius, we can increase the number of fish in the sea by nearly a third, while providing an additional 25 billion servings of seafood and increasing profits for fishing communities by twelve billion euros.

If we don’t act, we could lose a vital source of protein and nutrients that help support billions of people around the globe. Even before accounting for the impact of climate change, more than a third of the world’s assessed fisheries are at risk of collapse due to overfishing and a lack of policies that strike a balance between the ocean’s economic potential and its need to replenish itself. Experts warn that 80 percent of the world’s fisheries will be at asimilar risk by the end of the next decade if we don’t change how they are managed. 

Climate change adds to this challenge. Nearly all fish species are expected to experience changes in productivity, and half of them will shift across existing national boundaries in search of cooler water, testing international shared fishing agreements and sparking new conflicts over fishing grounds and profits. 

The good news is that overfishing – and the web of problems associated with it – is an environmental challenge that we have the experience to deal with. 

Decades of research and real-world examples have shown that our oceans can be incredibly resilient with good fisheries management. Smart decisions that ease pressure on fish stocks and give them time to replenish can yield results very quickly. In a number of countries, including the United States, Mexico, Namibia, Belize and the Philippines, sustainable management has eased fishing pressure, stabilised prices and sustained local fishing economies. 

Call to action

But only a few fishing nations are developing solutions that take into account the shifting stocks that this new research predicts. 

For example, Chile and Peru already recognise the conflicts these shifts might create. Both nations benefit from fishing grounds that are fed by the Humboldt Current, one of the most productive ocean ecosystems on earth that accounts for 15 percent of the world’s fish catch. Warming waters are creating radical shifts in the cycles of the sardine and anchovy fisheries, as well as movement of species like giant squid and smaller, but locally important, artisanal fisheries. 

In response, the two countries are beginning to share information on shifting stocks, discussing plans for observation and monitoring across the Humboldt Current region, and considering the types of joint management responses that may be necessary to deal with the effects of climate change on their fisheries. They deserve recognition for their foresight and cooperation, and more countries should follow their lead.

It’s tempting to view this research as more bad news for our oceans. On the contrary, I see it as an optimistic call to action – our decisions now can make a difference. Despite the impacts of climate change, there is a path forward that is not only good for our oceans, but good for the people and economies that depend on them as well.

Now, policy makers in fishing nations around the world must answer the call. The ocean waters are warming, and time is running short. 

This Author

Kristin Kleisner is a senior scientist with the Environment Defence Fund's fisheries solutions centre. She researches the science around combining spatial and rights-based management to achieve sustainable fisheries around the world.

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