We’re Running Out of Fish to Catch

Sam Westreich, PhD
Sep 30, 2019 · 5 min read

New technologies are doubling our fishing power every 35 years. So why aren’t we catching any more fish?

A fisherman in a boat. Despite new technologies, the level of fish brought in is staying constant. Photo by Unsplash

We have more available technology for locating and catching fish than ever before.

New mechanisms, such as GPS, sonar fishfinders, and echo-acoustic cameras are helping today’s fishing fleets grow more and more efficient at finding fish. A new study shows that the “fishing power” of fleets is doubling every thirty-five years, which works out to an increase of 2–4% per year.

This means that, given the same level of fish in the ocean, ten fishing vessels today can catch the same number of fish as twenty vessels in 1984, or the same number of fish as forty boats in 1950.

However, the average catch amounts for fishing fleets have remained the same — and when it comes to specific marine regions, or fisheries, the catch amounts are decreasing.

New regulations limit the number of boats that many countries can send out to sea — but this isn’t enough to prevent overfishing.

Policies Fail to Account for Power Creep

Most policies tend to focus on the number of boats on the water, rather than considering the fishing power of each boat.

This makes sense when most fishing studies are short-term, looking at the number of fish caught, number of boats deployed, number of people employed, and other factors over the course of a single year. These measurements are considered to be constants — it’s assumed that each person has the same fishing capacity year to year, and so the number of fish that will be caught is dependent just upon the number of people and boats.

But this doesn’t capture the full picture — this is like paying rent every month, but not noticing when rent keeps increasing. Even though you’re still making the same number of rent payments per month, you may be caught off guard when you’re suddenly broke.

There’s also a huge amount of power creep now coming out of southeast Asia, as many fisherman there switch from the “artisanal” methods, such as hand-casting nets or lines, to using motorized boats and trawling (pulling a large net behind a motorized boat). This rapid increase in fishing power is doing even more damage to fish stocks.

“Tragedy Of The Commons”

More efficient fishing vessels mean more damage done to depleted fish stocks. Photo by Unsplash

The term “tragedy of the commons” describes a situation where a shared resource is present, but each individual acts to their own self-interest, to the detriment of the entire group.

The concept was first described in 1833, by a British economist, but became popular nearly a century later when an article was written about the concept in 1968. It originally described a common grazing area in a small village. If a farmer put extra cattle on the grazing area, he would profit — but he’d also deplete the resource through over-grazing.

Collectively, the best choice is for no farmer to put out extra cattle, so as to preserve the common resource — but when each farmer acts independently in his own self-interest, his best choice is to put out more cattle. Thus, with every farmer choosing to put out extra cattle, the common grazing area is quickly destroyed.

31% of all fish species are overfished, and another 58% are fished at the maximum sustainable level.

This effect is happening with our oceans of fish. Each fisherman receives more profit if he fishes more, so it’s in his own self-interest to pull up more fish — even though it leads to overfishing and depletion of the fishing stock.

Current studies suggest that we’re on a crash course towards a world without fish. A 2006 study that looked at 7,800 fish species levels over a 4-year period concluded that every fish species will be collapsed by the year 2050, if we continue fishing at current rates. This may happen even faster, if power creep continues to increase the ability of fishing boats to pull out more and more of an ever-dwindling stock.

Several solutions have been proposed to the problem of overfishing, and some testing suggests that they may be able to slow, or even halt, the destruction.

Instituting a rights-based management of fisheries, where fishermen own rights to a share of the fish, helps transform the environment into a resource where the incentive is to sustain, rather than to squeeze as much value out before it is depleted. This has been tried in the United States, known as “catch shares,” and has reduced overfishing by up to 60% in some cases.

Fish farming, also known as aquaculture, can be another potential solution — but only if it’s performed sustainably. Roughly half of all consumed seafood is produced through farming. However, as most fish consume other fish as a food source, the majority of aquaculture uses wild-caught “forage fish” as the food for the farmed species. It takes approximately three tons of forage fish to produce one ton of farmed salmon. Fish farming also generates large amounts of fish waste and requires significant land or shoreline use.

Improving water circulation, switching to consumption of more herbivorous (plant-eating) species, and using more plant-based feed helps improve the sustainability of aquaculture, and can help take more pressure off our over-stressed ocean.

If we don’t make large changes to fishing policy for wild-caught fish, however, the increases in power and hunting ability of our fishing boats will soon push many more wild species to the brink of collapse. We can’t just keep building more efficient, more powerful boats — soon, there will be no more fish left for all that technology to find.

Sam Westreich holds his PhD in genetics, focusing on methods for studying the gut-associated microbiome. He currently works at a bioinformatics-focused startup in Silicon Valley. Follow on Medium, or on Twitter at @swestreich.

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Sam Westreich, PhD

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PhD in genetics, bioinformatician, scientist at a Silicon Valley startup. Microbiome is the secret of biology that we’ve overlooked.

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