Conventional fisheries are facing a supply crisis. Not only are fishermen catching fewer fish, the ones that are harvested are far smaller than those caught several decades ago.
Additionally, commercial methods used to capture fish damage delicate habitats, ensnare and kill other marine mammals and fish known as by-catch, while strict country-by-country treaties and regulations dictating fish quotas are largely ignored.
But Gizmodo’s Andrew Tarantola claims that’s changing with the help of aquaculture, and insists the practice is the agricultural revolution to industrial fishing’s hunter-gatherer method.
“Instead of sending out fleets of ships across the ocean in search of wild quarry, the fish are bred and raised in enclosed, human-controlled (or at least monitored) environments.”
Simply put, aquaculture is the farming of aquatic organisms including fish, mollusks, crustaceans and aquatic plants, with some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, and protection from predators.
Tarantola notes we’re domesticating fish with the annual production volume of farmed fish on the verge of surpassing wild-caught. The US aquaculture industry alone produces over a billion dollars worth of seafood annually.
But as Tarantola points out, we didn’t invent it. Aquaculture has been around since at least 6000 BC when Australians began raising eels in a 39 square mile patch of volcanic floodplains controlled by channels and dams.
“The Chinese raised carp trapped in lakes by receding flood waters for food as far back as 2500 BC (and through their efforts, invented goldfish). The Romans bred fish in grand ponds, as did early Christian monasteries throughout Europe in the Middle Ages.”
According to Tarantola, the US is the second largest seafood importer worldwide and one of its largest exporters. US aquaculture raises salmon, tilapia, striped bass, sturgeon, walleye, catfish and yellow perch as well as rainbow trout and bait fish like minnows. Catfish is the largest US aquaculture sector, accounting for 40 percent of all sales.
But fish farms aren’t without major drawbacks. Fish farms are a major source of pollution in the form of bio-accumulated toxins in fish feed and elevated exposure to dioxins and dioxin-like compounds that poison our bodies and destroy the ecosystem.
In 2010, a deadly and mysterious epidemic threatened farmed Atlantic salmon. Compounding the problem, infections can spread to wild fish coming in close proximity to marine pens. And escaped fish from Norwegian salmon farms interbred with wild salmon, and changed the genetic composition of the country’s wild salmon stocks.
Fish farms are also abysmally inefficient — it takes fifteen pounds of wild fish to get one pound of farmed tuna. Three pounds of wild fish are required to produce a pound of farmed salmon.
And the methods used in industrial farming in both fresh and salt water fish require high energy, and cause the kind of environmental degradation at par with industrial and chemical agriculture or factory farming of livestock.
Farmed Salmon Have 2-3 Times More Omega-3 Acids
Tarantola cites a 2004 Cornell study which found significant amounts of organochlorine contaminants in farmed salmon. Prolonged exposure could build up to dangerous levels for humans. But the same farmed salmon also possessed two to three times the amount of beneficial omega-3 acids than their wild cousins.
Steven Schwager, Cornell associate professor of biological statistics and computational biology explains that for a middle-aged guy who has had a coronary and doesn’t want to have another one, the risks from pollutants are minor, and the omega-3 benefits far outstrips the risks of the pollutants.
“But for people who are youngand they’re at risk of lifetime accumulation of pollutants that are carcinogenicor pregnant womenwith the risks of birth defects and IQ diminution and other kinds of damage to the fetusthose risks are great enough that they outweigh the benefits.”
Recirculating Aquaculture Systems
In addressing the intensive water supply and pollution aspect inherent in fish farms, recirculating aquaculture systems (RAS) have been invented where each hatchery cleans and reuses a set water supply in an indoor farm. This system allows fisheries specific control over the hatchery environment without the need for a fresh water supply.
“Not only can an RAS be located anywhere, it can produce fish year-round rather than seasonally. Other carnivorous fish like cod or tuna could theoretically be raised in this manner as well.”
Tarantola also mentions that larger fish species such as Kamapchi could soon be raised on the open ocean, towed about in huge pens by tender vessels so that waste is distributed over a much wider area and causes far less local environmental damage.
“Kampachi Farm, the ideological successor to Kona Blue Water Farms, which was founded in 2001 by a pair of marine biologists is doing just that.”
Tarantola stresses that although aquaculture isn’t the ideal end-all solution to our demand for seafood, it is currently one of the best and only viable answers.