Recent dire predictions of fished-out oceans by mid-century were dismissed last week by UW Professor Ray Hilborn, the fourth of eight lecturers in a series at the UW, “Food: Eating Your Environment.”
According to Hilborn, even scientist Boris Worm, who co-authored a headline-making article predicting a “global collapse of fish species” by 2048, has come over to the light side and is now more optimistic. The 2003 article by Randall Myers and Worm got “enormous traction in some elements of the conservation community,” Hilborn told his audience. But Worm now agrees that rebuilding efforts have made yields sustainable in seven marine ecosystems out of the 10 studied, and that “combined fisheries and conservation objectives can be achieved."
In short, argued Hilborn, there are plenty of fish in the sea. It’s the land that needs saving.
Hilborn is the Richard C. and Lois M. Worthington Professor of Fisheries Management at the UW and specializes in natural resource management, including the impact of fishing on marine ecosystems. In his talk, “Eating Fish to Save the Rain Forest,” he began by calculating the environmental costs of food production on land.
He charted the enormous and rising tonnage of animal waste, lost topsoil, and greenhouse gases from animal and vegetable farming, as well as the tons of petroleum, fertilizers, pesticides, and antibiotics used in the process. In addition, he cited statistics indicating that every year vast amounts of water — about 1,500 cubic kilometers of it — are required to produce the world’s supply of protein on land. Finally, nutrient runoffs from farming create huge dead zones offshore, as on the Louisiana coast.
Hilborn then pointed to certification principle #2 of the Marine Stewardship Council: "fishing operations should allow for the maintenance of the structure, productivity, function, and diversity of the ecosystem … on which the fishery depends."
“What form of agriculture would meet that standard?” Hilborn asked. Even organic farms reduce biodiversity by limiting native flora and fauna.
“If you want to minimize your impact on the environment, should you eat less fish?” was Hilborn’s central question. His answer: not when fish is a food requiring us to make comparatively small changes in the biosphere. He displayed a World-War-I-era poster with the slogan, Save the products of the land. Eat more fish; they feed themselves.
Hilborn conceded that catching fish reduces their numbers, that some kinds of fish will be depleted because the targeting of fisheries for rebuilding species isn’t perfect, and that trawling changes sea-bottom habitats. “If you want to take food from the ocean, it's not going to look the same as if you leave it alone,” he said.
However, the ocean isn’t looking like what Myers and Worm described in 2003, either. They claimed that large ocean fish had declined 80 to 90 percent by 1980, but this was not the case for tuna or billfish, which are “currently in the range of 50-70% of 1950 abundance,” said Hilborn. Further, overfishing of bluefin tuna had stopped by 1980. And the trawling that supplies one-fourth of the world’s food fish is sustainable, though it can result in “a different mix of species.”
Overall, said Hilborn, according to the FAO (U.N. Food and Agriculture Organization) the percentage of collapsed or overfished stocks stopped rising in 1990. Rebuilding strategies such as restricting catch sizes have helped. Ten years ago only about 33 percent of fishery stocks were fished at levels that would produce long-term maximum sustainable yield, but now about 80 percent of stocks are fished at sustainable rates.
About 10 percent continue at low levels of sustainability because of overfishing, and about 10 percent (including Southern and Atlantic bluefin tuna) are still in decline because they were fished much too aggressively. “The hard-core gloom-and-doomers say that fisheries management is failing. I would say that some fisheries are failing, so let's concentrate our energies there.”
What are some of the consequences of not fishing, when fish provide a quarter to a third of the animal protein in the world? If we don’t eat fish, the additional food production needed will likely come from “chopping down forests,” Hilborn said, as is happening in South America.
Everything we do has an impact, he said, and there are always environmental tradeoffs, but some don’t make the news. “We put ‘Amber Waves of Grain’ on pictures” of the vast wheat fields that replaced diverse ecosystems of forests with monocultures, while images of people engaged in large-scale fishing on the blue waves of the sea are labeled “rapers and pillagers of the ocean.”
Hilborn wondered, “Why aren't Greenpeacers piling on the dairy farmers? They don’t suggest that people shouldn't drink milk.” Many want to stop bottom trawling, he said, but if they succeeded “we would need five times the world’s present rainforest area to make up the protein by grazing.”
Hilborn concluded, “My point is not [that] we're going to get a lot more protein for the world from fish. From capture fisheries we're getting all we should. But we shouldn't try to decrease the catch, because there will be serious consequences on land.”
Tonight (Nov. 2) Claude Fischler, co-director of the Edgar Morin Centre, Paris, will speak about the importance of food-centered social and cultural customs such as eating dinner together, in "Social Sciences, Nutrition, and The Meal" at 6:30 p.m., Kane Hall 130. All lectures in the series are free and open to the public. Reservations (except for Nov. 16) have reached capacity, but walk-ins have been admitted. If you arrive by 6 p.m., you’re almost certain to get a seat.