Fish has become an increasing part of the Western Diet. In 2005, the average American ate 16.4kgs of fish, up from 9.9kgs in the 1960s. From sushi to fish tacos to shrimp cocktails, people are all swimming onto the seafood bandwagon. Taste aside, many considerations go into our decision to eat fish. Is it healthy? Is it safe? Is it sustainable? In the following post, I will guide you through each of those three categories to help you better shop, order, and eat fish in the future.
The 2015-2020 USDA Dietary guidelines suggested that Americans eat 8-12oz of fish every week. That is because fish are nutritional superheroes. From a macronutrient profile, fish are an excellent source of protein and low in saturated fat and calories. Fish are also filled with omega-3 fatty acids, a family of three fats that you need for brain development, heart health, and eyesight. There are some plant-based sources of omega-3 fatty acids, such as in walnuts or flaxseed. Yet, these plant sources only contain one kind of omega 3 called ALA (remember, there are 3), the least efficient type. Fish, on the other hand, contain the omega-3s EPA and DHA, which have longer fatty acid chains. Skip the fancy science, and that just means that they are more efficient in the body. For this reason, many doctors recommend that people get their omega-3s from fish instead of plant-based sources. Lastly, fish are an excellent source of iodine, vitamin D, iron, calcium, zinc, and many other minerals, all of which are essential to human health.
A quick guide to fish with the most Omega-3s
There is one serious health draw-back of fish, however- mercury. Mercury is a naturally-occurring chemical element that is found in many rocks. Certain anthropogenic activities, such as burning coal, have released mercury into the atmosphere. That mercury can make its way onto the ground or into the ocean through precipitation, falling dust, or just plain old gravity. So, now we have mercury in our oceans, lakes, and ponds. Fish at the very bottom of the food chain ingest that mercury. A bigger fish will swallow that little fish and ingest its mercury. Then, an even bigger fish will devour that big fish and all of its mercury. This process is called bioaccumulation, and that is why fish at the very top of the food chain have the highest mercury levels of all. Overeating mercury-contaminated fish can lead to mercury poisoning, which can damage the heart, brain, kidneys, lungs, and immune system.
A cartoon visualization of how bioaccumulation works
Not to fear, though. There are many free guides on the internet for those concerned about their mercury intake. For example, the FDA and EPA recently created a consumer chart for picking low-mercury options and suggestions of how often to eat specific species. Then, the Environmental Defense Fund recently launched the website Seafood Selector, which allows consumers to search for any fish and discover its mercury content. Both guides advise consumers to avoid bigger fish, such as King Mackerel, Bluefin Tuna, and Swordfish. Check them out for yourself to learn more about your favorite fish breeds.
A consumer chart created by the FDA and EPA to help consumers limit their mercury intake
That brings us to our third criteria for selecting seafood- sustainability. As a simple definition, seafood is unsustainable if you are extracting more fish than they can naturally replenish themselves. Remember, fish are very different from agricultural products. We cannot just plant more. They are living species that reproduce and migrate on their own accord. Other interpretations of sustainable seafood include limiting bycatch (sea species inadvertently caught with the desired fish) and avoiding damage to any local marine environments.
A video by Monterey Bay Watch that explains how fish can be unsustainable
Many have suggested that aquaculture could be the answer to sustainable seafood- these are fish bred and raised, like livestock, in controlled environments. Some raise the fish in tanks on land and others in net pens within marine bodies. Aquaculture does not deplete wild fish populations nor have any bycatch. However, not all farmed fish are created equal. Some overcrowded fish farms can build-up waste and leak toxic water back into oceans, lakes, and ponds. Farmed fish are also at an increased risk for disease, which can infect other wild fish. Farmers can use antibiotics to prevent such disease, but in doing so, they risk breeding antibiotic-resistant bacteria. Farmed fish can also displace local marine environments. Nevertheless, farmed fish still can be an excellent source of sustainable protein, as can wild-caught fish. One just needs to know where their fish is coming from.
A Salmon Farm in Norway
To help consumers, a handful of certification programs have emerged in recent years. The most well known of these labels include the Aquaculture Stewardship Council (ASC), the Best Aquaculture Practices (BAP), and Naturaland for farmed raised seafood, and the Marine Stewardship Council for wild-caught fish. For consumers who find certifications and labels too confusing, the Monterey Bay Watch offers free consumer guides for finding sustainable seafood.
All in all, seafood is an excellent source of protein, vitamins, and minerals. Some species are more harmful to us and the planet than others, but by following these guides and recommendations, we can eat our fish healthily, happily, and eco-friendly.