But, about 86 percent of marine fish stocks are fully exploited or overfished, meaning our supplies of fish are rapidly dwindling. Farmed fish, called aquaculture, has become more prominent, and you’re likely to see more choices of farm-raised fish at the grocery store. But how does it compare to wild caught?
What’s better: farm raised or wild caught?
It depends on the type of fish.Farmed or wild, you're likely to get similar nutrient content. But, each type of fish carries different environmental effects and health risks based on fishing or farming method.
From an environmental perspective, the basic rule for knowing which to get is the amount of input versus the output. Vegetarian fish are better as farmed fish rather than meat eaters like salmon. It may take as much as three pounds of feed to grow one pound of carnivorous fish.
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| Coastal net pens. Photo from NOAA via Flickr. |
Farm-raised Fish
Auqaculture means breeding aquatic animals and plants in a controlled environment. Methods of raising farmed seafood include raceways, tanks, net-pens, ponds, and lakes.China and other Asian countries are the top producers of farm-raised seafood, and much of the fish sold in the United States is imported from China.
Concerns
As with food animals raised in close quarters, disease and waste management are major concerns. Veterinary drugs and antibiotics are used in fish farms and run the risk of spreading to the surrounding waters and contaminating those fish and drinking water supplies. Having so much fish waste concentrated in one area can harm the surrounding waters. Herbicides are also used in fish farms to reduce algae growth.
Raceways and tanks do not breed fish and aquatic plants in inland waterways and may be more environmentally friendly methods.
Better choices
Mollusks and aquatic plants are the best choices for farmed seafood, along with tilapia and other vegetarian fish. Salmon, shrimp, and other crustaceans require large amounts of inputs and have much higher environmental and health costs.
Third-party organizations have also created certification programs to set standards for sustainable aquaculture. Look for labels from the Aquaculture Stewardship Council or the Marine Stewardship Council. The United States does have high quality standards for aquaculture, but U.S. aquaculture makes up a tiny fraction of the supply.
Wild-caught Fish
Our supplies of wild-caught fish are running out, so paying attention to the fishing methods used and avoiding fully exploited fish are what’s key to leaving decent fish stocks for our kids and grandkids.
Concerns
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| Salmon fishing. Photo by James Brooks via Flickr. |
Large amounts of by-catch, which you get with methods like trawling and dredging, harm the seafloor and reduce the organisms living there.
The primary health concern with wild-caught fish is mercury. Those levels are higher in swordfish, king mackerel, tilefish, and others. Salmon, catfish, and trout tend to have low levels of mercury. The general rule is to eat the fish that may be high in mercury less often.
Better choices
When choosing wild-caught fish, look on the package for the fishing method used. Trolling, jigging, and using pots and traps have little to no by-catch and do far less damage to the surrounding ecosystem.
A Note on Interconnectivity
Although aquaculture is looked at as a possible solution to overfishing, it is still heavily dependent on wild-caught fish. Anchovies are the most commonly caught species and are primarily used as fish oil and fish feed.Sustainability is talked about so often these days it seems to have lost much of its meaning But our food system, environment, and public health are closely related. You can encourage our food producers toward sustainability through your buying choices.
You can find many guides online to help you choose what fish to buy. Most of the ratings for these guides are based on what that organization thinks is most important. This one from the Monterrey Bay Aquarium is a good one.
