At the beginning of this summer, the United Nations Dr Report Humanity now eats more farm-raised fish than ocean-raised fish.
The milestone marked the end of a decade-long boom in aquaculture, or fish farming, an industry that produces four times more fish today than it did 30 years ago. The growth of fish farming was primarily motivated by Govt subsidy Around the world, the world’s wild fisheries peaked in the 1990s and countries were looking for another source of seafood.
There has also been aquaculture increase It is supported by academic institutions, philanthropic foundations, non-profit organizations and the United Nations in the belief that aquaculture can give a break to overexploited oceans and promote more sustainable food security.
But fishing comes with — pardon the pun — some big catches. Some of the most valuable cultivated species, viz Salmon and troutWild-caught fish must be fed when carnivorous and farmed. Along with farmed shrimp, several omnivorous fish species are also fed wild-caught fish. All told, something 17 million 91 million metric tons of wild-caught fish are sent to the aquaculture industry annually.
In other words, the overexploited ocean that was supposed to relieve pressure became a new source of exploitation. According to a New research published Science advances By a team of researchers from the University of Miami, New York University and the conservation group Oceana, aquaculture may be killing more wild-caught fish than previously thought — a finding that calls into question the sustainability branding of the aquaculture industry.
The researchers found that the amount of wild-caught fish — typically from small species such as anchovies and sardines — feeding the top 11 farmed fish and crustacean species could be 27 to 307 percent higher than current estimates, or more, depending on how it is harvested. Calculated (The high degree of variability and uncertainty is due to the lack of valid industry data on what is fed to farmed fish.)
“The harvesting of wild fish for aquaculture production is probably much higher than we’ve been told,” Spencer RobertsA PhD researcher at the University of Miami and lead author of the study, told me. “The story of fish farming feeding the world is very optimistic, but it is based on incomplete data. So what we are trying to do is paint a more realistic and comprehensive picture.”
The aquaculture industry now uses nearly one-fifth of the global wild catch to feed farmed fish, adding pressure to already taxed oceans and threatening the food sources of some coastal communities in the Global South. It has also created a new area of animal suffering: fish farms, sometimes called “water factory farms” by animal advocates, often house fish in conditions similar to overcrowded industrial farms that confine pigs, chickens and cows to land.
“There’s a lot of hype, not just in the media, but in administrative conversations about aquaculture or blue food as a sustainable source of food and a way to combat hunger or reduce food insecurity, but a lot is ignored,” Roberts said. “I hope so [the new research] prompting other academics, but especially policy makers, to question some of the narratives.”
In fish farming it can waste more fish meat than it produces
The aquaculture industry measures the amount of wild-caught fish required to produce a unit of farmed fish using the fish in:fish out (FIFO) ratio. In 1997, in the early days of fish farming development, the industry had a FIFO ratio 1.9That means for every kilogram of fish it has to catch and kill about two kilograms of fish used for food.
By 2017, according to a group of aquaculture experts, that number had dropped to .28, an all-time low, as the industry switched most of its diet from wild-caught fish to crops like soy and corn, along with vegetable oils, minerals, and vitamins.
This was the result published in the natureAnd it is widely cited in food systems research. The fish farming industry keeps its FIFO ratio at a Similarly low ratesClaim a Major sustained wins. (It’s worth noting that something the nature The authors of the paper have close ties to the aquaculture and animal feed industries.)
But the model used in that paper was incomplete, according to Roberts. For example, it did not include trimmings, parts of a fish that are considered byproducts that end up in fish feed, or fish that are unintentionally killed and become fish feed. The model uses industry data to report that, on average, only 7 percent of its farmed fish feed consists of wild-caught fish; The rest consists of crops. Other data sources, including the Monterey Bay Aquarium, the Food and Agriculture Organization of the United Nations (FAO), and another group of researchers, report a higher percentage of wild-caught fish in farmed fish diets.
When correcting for these factors from the original model, Roberts and his co-authors found that for the top 11 farmed species, the fish in:fish out ratio of the global aquaculture industry was much higher than the original model estimate of 0.28, from 0.36 to 1.15, or from 27 307 percent higher.
Then the researchers ran the numbers again, finding other fish and other marine animals killed unintentionally by commercial fishing vessels and removing fish farms that didn’t feed their animals. This adjustment brings the industry’s FIFO ratio to between 0.57 and 1.78, or 103 to 535 percent higher than the original model. This means that at the above estimate of 1.78, the industry still produces a net loss of fish, just as it did in the 1990s.
For carnivorous farmed species such as salmon and trout, aquaculture demand is particularly high for wild-caught fish. According to Roberts and his co-authors’ upper-bound estimates, it could take up to 6.24 kilograms of wild-caught fish to produce just one kilogram of salmon—230 percent more than previously estimated.
“This appears to replace the current paper [earlier studies’] Simplifying assumptions with better sources of data or better estimates,” said David C. profitis an aquaculture and fisheries research professor at the Johns Hopkins Bloomberg School of Public Health, who was not involved in the research. “What they found was that the food was using more fish than previously thought.”
But looking at FIFO ratios for the industry as a whole obscures major differences in feeding requirements across species.
“It’s hard to say, ‘Well, aquaculture is a thing.’ It doesn’t. It’s abundant and different species with different needs,” Love said. The largest differences are among herbivore species, such as carp and tilapia with FIFO ratios up to .83 at the upper bound of the adjusted model, and among carnivorous species such as salmon and trout with FIFO ratios up to 5.57—a nearly sevenfold difference. Shrimp, freshwater crustaceans and catfish also require more wild-caught fish than the upper limits.
Paul ZajicekThe executive director of the National Aquaculture Association, dismissed the study’s findings in an email to Vox.
“As noted by the authors, such analyzes are very challenging and we doubt that a rival analysis would show a difference,” Zajicek wrote.
But the huge amount of wild-caught fish fed to farmed fish is only one part of the bigger picture of fisheries instability.
Environmental, social, and animal welfare costs of fish farming
Although over time the aquaculture industry has reduced its reliance on wild-caught fish on a per-kilogram basis, replacing it with corn and soy.
“Fishmeal is every bit that you [remove from fish diets] Still have to replace it with something from the land,” said Jennifer Jacketis a co-author of the study and professor of atmospheric and earth sciences at the University of Miami. “We are already concerned about deforestation [feeding] Land animals and now farmed salmon are also contributing to our world’s deforestation.”
This explosion in crop use — a nearly fivefold increase in recent decades — doesn’t just mean more potential deforestation. These crops are grown using a lot of artificial fertilizers, which pollute waterways and harm wild fish. It is a significant source of greenhouse gas emissions and displaces land that could otherwise be used to grow food directly for people.
“What we’re talking about is not an increase in efficiency so much as a change in ecosystem pressure like the Humboldt Current. [in Peru]Where anchovies come from, to ecosystems like the Amazon rainforest where soy comes from,” Roberts said.
What we need, Love of Johns Hopkins University told me, is a holistic life-cycle assessment that covers not only a species’ FIFO ratio but also other metrics such as carbon footprint, water use, land use and pollution. A more accurate picture of the environmental impact of aquaculture.
one such assessmentpublished the nature In 2021, it was found that seaweed and bivalves, like oysters and mussels, have the lowest ecological footprint of all aquaculture foods. But it also illustrates the complex range of trade-offs between different species and whether they are wild-caught or farmed. For example, farmed salmon uses little land and water but uses a lot of wild-caught fish and causes a lot of pollution. In comparison, farmed carp consume almost no wild fish but require much more land and water.
When we farm or fish on the same scale as animals raised on land, we overexploit one ecosystem or another, making it an inefficient way to produce protein compared to plant-based agriculture.
The rapid growth of fish farming has also brought serious ethical implications.
Animal rights advocates have decried conditions in fish farms, where fish often suffer from the same problems as land-raised animals, such as overcrowding and disease. slave labor Commercial fishing vessels and inside fish processing plants have long plagued the industry.
Wild fishing for fish feed also undermines food security in some regions. For example, many of the fish caught for the aquaculture industry come from West Africa and “may be part of the West African diet, but are sold to fish meal plants as feed for use in fish farms,” Love said. This fish is very last rich marketLike Europe and North America.
“Although the aquaculture industry routinely uses the food security narrative, their top products, salmon and shrimp, are valued not for their nutritional value but for their export value,” wrote Patricia Mazlouf Oceana, a biologist and co-author of the study, separately Analysis of the aquaculture feed industry.
Much of the conversation among governments, philanthropies, non-profits and academics about the future of seafood – something that is expected to grow 30 percent By 2050 – Balancing conservation and economic development. But the famous environmentalist and writer Dr Carl SafinaA Recent CommentsSomething bigger is called for: a clear look at the environmental and social harms of aquaculture — which requires us to fundamentally rethink aquaculture. “Problems in animal aquaculture stem from a failure of care and conscience,” Safina writes. “Solutions require not ‘balanced’ goals but economic assessments and moral calculations to modify policies.”
