How to Farm Fish Without Killing the Planet
by Owen James Burke
Photo: Ocean Farm Technologies.
Aquaculture has been the world’s fastest-growing food sector for several decades, and some argue it is the only feasible answer to the predicament of trying to feed a growing global population that is expected to reach 9 billion by 2050.
And they have a point. Since the 1970s, roughly half of the world’s fish and seafood harvested for human consumption has been farmed, and in 2011, aquaculture exceeded global beef production for the first time in history.
But how can it be done without introducing pathogens (as well has hormones and potential toxins, like antibiotics) and depleting the ocean of precious oxygen and nutrients?
While there appears to be plenty of space in the ocean for the industry to expand, many, if not most of these farms lie in lakes and near-coastal waterways where, if not properly managed, they pose a serious threat to the surrounding environment.
Fish, like people, have population density thresholds which, once broken, increase susceptibility to pathogens and diseases through, among other things, the aggregation of fish waste. Keeping in mind that many farms exist within enclosed waters, the resulting stagnation poses a significant threat not only to the species within the enclosures, but the natural ecosystem around them, especially if contaminated fish escape pens and interact with wild stocks.
Recently, fisheries researchers at Ocean University and the Yellow Sea Fisheries Research Institute in China are among the scientists spearheading the search for sustainable aquaculture reports Christian Science Monitor.
Opposite South Korea on the Yellow Sea, Sanggou Bay is a struggling fishing community now turned ground zero for global aquaculture, where a multi-trophic model of fish farming is being implemented: among 6,000 cages ranging 16 miles offshore, everything from seaweed and nitrate-and-phosphate-filtering bivalves (i.e., mussels, oysters) to finfish like salmon are being raised together in an effort to balance the impact of the farms on the ecosystem. Currently, the hope is to venture further, perhaps up to 100 km (62 miles) offshore, Guo Genxi, a research fellow at the South China Sea Fisheries Research Institute tells CSM.
In Mexico: Offshore Aquaculture in Geodesic Domes
Screenshot from Vice/Motherboard’s video below.
Across the pacific in La Paz, Mexico (and beyond), Steve Page, formerly the Environmental Compliance Officer at Atlantic Salmon of Maine, founded Ocean Farms Technologies in 2005 which designs geodesic domes (“AquaPods”) for offshore waters, his answer to the shortcomings of aquaculture that have given the sector a bad rap in the past. Stationing Ocean Farms Technology’s “AquaPods” offshore enables better circulation inside the pods and out, avoiding some complications compounded by stagnation that occurs in near-coastal and inland waters.
As it stands, China’s Sanggou Bay and Page’s Ocean Farms Technologies may help prevent fish waste from piling up alongshore, but what about the hormones, antibiotics, and other drugs used to treat fish pens? Aquaculture is still in its infancy, and a long way away from becoming entirely sustainable or organic, but moving farms offshore and into deeper waters where ocean currents can flush waste could hold promise to eliminate the need for harmful drugs like antibiotics which as it stands now are the only way to keep farmed fish “healthy” and “safe” for human consumption.
Read more about Sanggou Bay multi-trophic farming and a burgeoning oyster farming scene in Cape Cod, Massachusetts at CSM, and watch Vice Motherboard‘s documentary on Steve Page and Ocean Farms Technologies below.