You’ve heard for years now that fish and seafood make for healthy eating. You’ve read up on their high quality protein and the other nutrients some species contain. You’ve resolved to get more seafood into your diet. But since you’re putting some thought into what ends up on your plate, you know there are matters other than nutrition to be considered here. Where fish and seafood are concerned, the biggest two issues are sustainability and contaminants.
Sustainability is about the future. Specifically, it’s about the future of various species of fish and shellfish. Many wild populations of fish and shellfish are in trouble, due to harvests in excess of a population’s ability to replenish itself (commonly called “overfishing”); decline in population because of disease or environmental factors; a species being slow to reproduce; poor management of stocks by authorities; or some combination of these factors. Annual total harvests of some species have declined notably for some years now. Given that the world’s human population is not expected to be lower anytime soon, it behooves us to manage stocks of fish so that future generations will be able to take advantage of these beneficial sources of food.
If some wild fish/shellfish populations are low in numbers, wouldn’t more fish farming, or the farming of more species, be a solution? Not necessarily. There are several significant problems with aquaculture (fish farming) as it’s currently conducted in many areas. Among these are the pollution produced by farmed fish (commonly called “effluent”) and the escaping of farmed fish into the wild. In open net pen aquaculture (in which the fish are raised in a body of water in a “pen”, formed by a net), the effluent from thousands of fish is released, usually untreated, into the open water. This can mean decreased water clarity, which leads to sunlight being blocked, and that has a negative impact on the photosynthesis of aquatic plants. Further, as part of the effluent and unconsumed feed, nitrates, nitrites, ammonia, and phosphates can reduce the water’s dissolved oxygen content and lead to an increase in the phytoplankton population; both conditions are harmful to plants and sea creatures in the area.
The question of escaping fish seems trivial; what’s the big deal if a few fish slip through a net pen into a river or the open ocean? In fact, it is quite serious. We’re not talking about just a few fish here. The country of Norway has a “zero escapes” policy for fish farming. Yet in 2005, 1.2 million fish escaped from Norway’s open net pen farms. Re-capturing such escapees is often impossible, and these fish can bring diseases or pests in among their wild kin. Additionally, because farmed fish grow faster than their wild cousins, they’ll be larger as sub-adults than their wild relatives, so they might outcompete wild fish of their age group for food or space. And if you can’t survive to sexual maturity, you can’t reproduce.
Finally, there is the issue of contaminants. I’m not talking about pollutants produced by the fish this time; these contaminants are contained in the fish and seafood you eat. Yeah, it’s not something I really wanted to read, either, but in some species, contaminants are present in levels we have to think about. These contaminants include mercury as well as over 200 different manmade chlorinated industrial chemicals known collectively as PCB’s.
Have I scared you away from all fish and shellfish yet? I hope not. Some of what I’ve written sounds very alarming indeed, but it isn’t true for all species. Not all species are in jeopardy or have poorly-managed stock; sometimes, a particular type of fish or seafood will be doing well in one area of the globe and poorly in another. Likewise, not all contain toxin levels of concern. But how do you know which types of fish/shellfish are OK, and which you should avoid?
If you surf over to www.thefishlist.org, you will find rosters from three separate organizations. Perhaps the best-known is the Seafood Watch List from Monterey Bay Aquarium. Here you’ll find guides divided up by areas of the US (you can also find a National Guide). These guides are further subdivided into “Best Choices”, “Good Alternatives” and “Avoid” categories, and you’ll quickly discover that the source of your fish or seafood can be quite important. Species with higher toxin levels are noted. Environmental Defense Fund has their own version of this list, dividing fish and seafood species into “Eco-Best”, “Eco-OK”, and “Eco-Worst” categories. This listing goes into more detail regarding species with significant levels of contaminants, even suggesting maximum number of servings per month by age group. Finally, Blue Ocean Institute has a third, similar guide, with species represented in a color spectrum according to abundance and harvest methods; red flags are used to denote mercury or PCB health risks. All of these guides can be printed out in miniature form, so that they’ll fit conveniently into a wallet; the first two are even available for your mobile phone.
These guides are an easy way to make choices that are better both for your health and fish/shellfish populations throughout the world. So don’t be afraid to dig into a serving of seafood; just be smarter about it!
Sources:
—Food & Water Watch, www.foodandwaterwatch.org
