Wild versus Farmed: Fish Sourcing
I recently published a post on omega-3 fatty acids. As I mention there, one of the best animal sources of omega-3s is fish, especially salmon and other medium to small fish varieties.
In this post, I help you understand what to look for when purchasing fish and other seafood and why sourcing matters.
When possible, purchase wild-caught fish. Farmed fish, even when organic, is grown in underwater net pens or sea cages and fed a diet of plants (like soy), grains, and fishmeal. For instance, in farmed salmon, the omega-3 levels are dependent on what type of feed they eat (1). In wild salmon, the amount and type of omega-3s found are based on the algae and plankton found in their native diet. This native diet gives wild salmon their bright orange color. Farmed salmon are often grey and dyed pink/orange.
What are the the problems with farmed fish?
Farmed fish operations can become overcrowded and cause contamination. Pollution can also occur beneath net pens in low current areas. Some studies have reported that farmed salmon contain high levels of PCBs, cancer-causing polychlorinated biphenyls, and other contaminants “at levels that raise health concerns” (2). Farmed fish have also been found to spread sea lice that infect native fish populations. Regulations in the US and British Columbia require monthly monitoring of sea lice. If there are more than 3 lice per fish, authorities must be notified and treatment administered (3).
You can still eat farmed fish.
Tim Fitzgerald, a scientist and sustainable seafood expert at the Environmental Defense Fund explains that fish farming practices are improving and the number of healthy and sustainable farmed fish options are growing. As with any food, the sourcing matters. There are responsible farmed fish operations that have introduced healthier feeds and more sustainable practices. For instance, Wegmans, Whole Foods, Eataly, and many local fish stores have strict quality standards to ensure the fish they purchase come from responsible farms with strict regulations on safety and sustainability. Ask your fish store about their purchasing practices. Moreover, from a supply standpoint, we do not have enough native fish in the sea for everyone to rely solely on wild varieties. As Mr. Fitzgerald explains, completely avoiding the farmed variety “removes 50 percent of the US seafood supply from your choices” (4).
What fish should I buy?
Two points to think about when purchasing fish: is the farmed fish from a reputable farm? And is the wild fish from a generally pollution-free environment?
When choosing farmed fish, farmed varieties of arctic char, rainbow trout, and oysters are generally produced responsibly and are also high in omega-3 fatty acids. From a health perspective, farmed salmon is also still a great choice. It is rich in omega-3 fatty acids, just like wild salmon. As mentioned, when purchased from a responsible source, farmed salmon is also a safe choice. Salmon, arctic char, trout and oysters are also good choices because they are low in mercury. It is best to avoid the big fish like shark, swordfish, and tuna and instead, go for the smaller fish, especially anchovies, sardines, and shellfish. Check out my omega-3 post for some great graphics as well as the Seafood Watch by Monterey Bay Aquarium.
Resources:
https://well.blogs.nytimes.com/2014/12/18/ask-well-wild-fish-vs-farmed-fish/?ref=health&_r=2
https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish/FarmedSalmon