The Fragile Promise of Sustainable Aquaculture
On the Yale Farm, our focus is food. We grow it. We savor it. We talk about it: how to cook it, how to more equitably distribute it and, more broadly, how to create a more sustainable and inclusive food system. This last question is tough and enormous, requiring a consideration of an often-overwhelming multitude of different factors. And yet, widely-encompassing as they are, these conversations rarely stray past our coastlines.
We talk a lot about agriculture. We talk a lot less about aquaculture, and fishing more broadly. The lopsidedness is quite understandable: we aren’t growing or using seafood, save for our usage of kelp as fertilizer to more fully close nutrient cycles. (The Yale Farm buys kelp from an nearby aquaculture operation that grows kelp off of the nitrogen and phosphorus run-off from Connecticut’s agriculture.) The Yale Sustainable Food Program’s academic and experiential foci often reflect the farm’s physical landedness, as the vast majority of Global Food Fellows and Chewing the Fat speakers work on issues of food and agriculture, rather than fish and aquaculture. Yet, as we strive for holism, it’s worth expanding the institutional perspective even farther outward to look at the vital role that fish, aquaculture and oceanic foods must play in a just and sustainable food system.
Domestic consumption of seafood has been on a sharp incline in the past few years, a trend seen by public health experts as a big victory. Although nutrition guidelines are constantly in flux, the healthfulness of fish protein is one of the most agreed-upon recommendations. This makes the remaining question ever more important: where will we get all this fish from?
“Approximately 85% of the world’s fisheries are exploited at levels equaling or surpassing their maximum sustainable yield. Yet domestic and global demand for seafood continues to rise, so aquaculture has become a crucial part of meeting this demand. Over 50% of seafood worldwide now comes from fish farms, a percentage that is expected to increase steadily over the next several decades. But this production is not evenly distributed across the world’s waters — 89% of aquaculture production occurs in Asia, while the Americas account for only 5% of global output. Though the United States is one of the world’s largest seafood consumers, 91% of the country’s enormous domestic demand is met through imports. According to the National Marine Fisheries Service (NMFS), domestic aquaculture supplies only five to seven percent of U.S. demand, and the vast majority of this comes from freshwater species and marine shellfish.”
This excerpt is from a blog post I wrote two summers ago while researching aquaculture legislation at the Environmental Law Institute. Until then, I knew a lot more about food and agriculture than I did about fishing and aquaculture. Through the research process, I became fascinated by this world of common ownership, perceptions work, behavioral economics and artisanal and industrial production — a world of academic and physical work that both relates so closely to the agricultural system and differs sharply from it.
I decided to further pursue this interest, which led me to a position at a research lab in the Bahamas. I wrote this piece from the Cape Eleuthera Institute, where I worked as a sustainable fisheries research intern. The Institute focuses on conservation, especially on marine reserves, sharks and turtles, rather than on fisheries. However, the Institute also runs a variety of different hands-on aquaculture projects as well as a current anthropology study on fishing perceptions. Many of the failures and triumphs of the aquaculture projects here illuminate the problems and potential of aquaculture in general.
Take, for example, the question of large-scale net-pen finfish aquaculture. This is one of the most common methods of farming salmon and other pelagic fish. Fish are first raised to juvenile size in a hatchery, then transferred to massive net enclosures in the open ocean where they feed on a diet of fish food, antibiotics and often smaller fish. (Sidenote: There’s also a more environmentally harmful method called “ranching,” in which fishers catch wild juveniles and raise them to market size). Environmentalists are distrustful of these net-pens, which carry increased risk of pollution, disease and cross-breeding with wild stocks. Yet there’s also a lack of research on the ecological effects of these systems and the potential for decreased environmental impact. To that end, there was a cobia aquaculture project started down here about ten years ago — and the project was eventually put on hold, due in large part to sharks breaking in to the open water cage. It was an answer I didn’t anticipate, but it’s been interesting to learn about the less visible, seemingly minor hiccups that can derail these investigations into how to feed future generations.
As the cobia project fizzled, the on-land hatchery was turned into an aquaponics test trial. Aquaponics systems combine hydroponics (produce grown in water instead of soil) and freshwater aquaculture. Here, the project leaders created a closed system in which tilapia and bacteria cooperate to provide the nitrates needed for leafy green growth. Aquaponics, as well as closed-system aquaculture in general, receive praise from most environmental watchdog groups for their decreased risk of pollution and disease, though they can be more energy-intensive. The project provides the Institute and its sister program, the Island School with all its greens, but the fish are too small and bony to really enjoy. Again, a seemingly small issue — people’s preferences for larger, meatier fish — trips up a project that works well otherwise.
There’s also a growing interest within the food world in multitrophic aquaculture, a parallel system to on-land polyculture. Multitrophic aquaculture, while still in its infancy, tries to integrate production of several different species that complement and balance each other. The visions and test for these systems vary: one could look like shellfish and seaweed production bordering finfish net-pens to absorb their extra waste. Here, it looks like a visiting researcher’s investigation of spider crabs’ potential to feed on the excess algae that covers net-pens.
Relatively little is known about the effects of these aquatic methods of food production, creating a landscape (or seascape, as the case may be) rife with risk, but also with possibility. The most amazing part of these hands-on experiences for me has been just realizing how new this work is and how so little is still unknown, how much of this growing field is still just tinkering and testing. Fishing landings worldwide are often misreported or not recorded at all, open ocean fish remain mysterious, plastic accumulation in fish is understudied, and the effects of our massive and increasing aquaculture production are still a question mark. What we do know is that the answering these questions will be crucial in creating a sustainable and balanced food system, on land and off.
Hannah Hauptman JE `18.5 is a History major.
