Marine fish stocks are key to the world food system, with fish accounting for 17% of all animal protein consumed worldwide, 26% of which is consumed in least developed countries. For people who work in fisheries and aquaculture, the ocean is also a significant source of income.
The sustainability of fisheries is essential to the livelihoods of millions of people in coastal communities, especially in developing countries. However, concerns are high that overfishing is increasing and fish stocks are declining. Existing analyses have suggested that close to 90% of the world’s marine fish stocks are fully exploited.
But a new study published in the Proceedings of the National Academies of Sciences (PNAS) of the United States on January 13th 2020 has cast further doubt on this.
Looking at data from around 30 countries, researchers found that intense fisheries management actually results in healthy or improved fish populations while the opposite leads to overfishing. When done well, they say, fisheries management is the solution for keeping fisheries sustainable.
University of Washington professor and lead author of the study, Ray Hilborn, says that concerns about overfishing come from the narrative that fish stocks are declining worldwide when in fact, the opposite is happening. A study published in 2006 said that if current trends continue fish stocks will collapse by 2048. This drew much attention.
‘Bad news stories tend to make front pages of the newspapers,’ he said.
‘When stories appear that say all fish will disappear by 2048 it makes the front page of the New York Times or is featured in the BBC evening news. It’s also in the financial interest of some groups such as environmental NGOs to play up the demise of the oceans, while there are other, somewhat overlapping, interests with an agenda to stop marine fishing or reduce it as much as possible.’
After collaborating with the first author of the 2006 study, Ray Hilborn published a paper in 2009 in the journal Science. This showed that on average, stock abundance appeared to be stable. He then worked to build a data set on the abundance of fish stocks, rather than just the reported catch.
‘The 2009 paper really showed that for the places where we had abundance data, which at the time was about 20% of the world’s catch, populations were stable, not declining,’ he said.
Now, more than a decade later, Ray Hilborn’s latest research, titled Effective Fisheries Management Instrumental in Improving Fish Stock Status, is a follow-up of his work in 2009. It shows how the intense management of fisheries has resulted in increased abundance of fish stocks.
A newly updated study database – the RAM Legacy Stock Assessment – was used, with information from fisheries representing 49% of officially reported landings, or about 880 fish populations from around the world, including Europe, North America, Australia, New Zealand, South Africa and South America.
The team found that in the managed fisheries, fishing pressure increased and abundance declined until around 1995, when the trend reversed. By 2005, biomass was rising and by 2016, the average biomass of assessed fish populations was higher than levels needed to produce a target level referred to as Maximum Sustainable Yield (MSY).
‘The key contribution of this paper is fisheries management, that the places that have implemented fisheries management are getting better and the places that haven’t aren’t,’ Ray Hilborn said.