June 2012 Issue

Eating Seafood Sustainably
By Sylvia Geiger, MS, RD
Today’s Dietitian
Vol. 14 No. 6 P. 38

Experts discuss the controversy of overfishing and ways to choose seafood varieties that protect endangered species.

People want to buy food that tastes good and is good for their health and the health of the planet to avoid compromising the ability of future generations to feed themselves.

But in the case of seafood, knowing what to buy can be confusing. “Close to a third of wild fish populations around the world are overfished, and another 53% are fished to capacity,” says Kate McLaughlin, seafood program director for the Blue Ocean Institute, a conservation organization based in Cold Spring Harbor, New York. “Some species—Atlantic bluefin tuna or orange roughy—are at such low numbers that unless people stop eating these fish now, their numbers may never recover.”

These grim warnings are especially paradoxical because they come at a time when Americans are being told to eat more fish because it’s so good for their health. So where does that leave the consumer or the dietitian who wants to eat more fish and make that recommendation to clients? Is it even possible to balance health, nutrition, and seafood sustainability? The answer is yes, but it requires that we as consumers ask the right questions, train our palates to eat different varieties of fish, and understand that responsibly sourcing seafood is an always-moving target.

Eat More Fish
The 2010 Dietary Guidelines for Americans recommend that people increase their per capita weekly fish consumption from 3.5 oz to 8 oz. Women who are or are planning to become pregnant or who are nursing should increase their consumption to 12 oz per week.

The first recommendation is based on meta-analysis data, which has concluded that eating 8 oz per week of a variety of fish provides an average of 250 mg/day of the omega-3 fats EPA and DHA, and this intake is associated with a 36% reduction in cardiac deaths from sudden cardiac arrest with or without preexisting cardiovascular disease. The benefits of adequate omega-3 fats for optimal neurological development are the basis for increasing the Dietary Guidelines recommendation for pregnant and lactating women and for young children. Regularly eating fish as part of two meals per week is considered the optimal food-based way to get adequate amounts of EPA and DHA, according to the guidelines.

A common misconception is that fish and seafood have undesirably high levels of the environmental toxins mercury, dioxin, and polychlorinated biphenyls (PCBs). However, fish contamination is comparable with that of other protein foods such as beef, chicken, and pork. In fact, greater than 90% of dioxin and PCBs in the US food supply comes from nonseafood sources.1,2 Mercury is a toxin that bioaccumulates and for that reason, the Environmental Protection Agency (EPA) recommends that pregnant and lactating women and young children avoid eating four long-lived fish: swordfish, shark, tilefish from the Gulf of Mexico, and king mackerel. The EPA has no health warning to limit seafood consumption for any other population group.3

A recent analysis looking at the potential risks for exposure to environmental toxins vs. the overall benefits of consuming seafood overwhelmingly conclude that the benefits outweigh the risks.4

Concepts in Seafood Sustainability
A fish species can be overfished—meaning that its population is below a prescribed threshold, essentially jeopardizing its survival. Secondly, a species can be subject to overfishing, a rate of fishing or harvesting that’s too high for the stock to replenish itself. Many environmental factors, such as ocean acidity, temperature, oxygen levels, and pollutants, as well as fishing techniques impact marine habitat and sustainability. But greenhouse gas emissions, water usage, upstream waste, and pollution also can factor into the problem. Currently, rating systems that define seafood sustainability don’t consider all these variables. Instead, they focus more on numbers of fish or on fishing practices.

As a category, animal protein foods have a greater environmental cost compared with plant-based foods, but fish are seen as a greener choice. Fewer greenhouse gases are emitted and less water is used when dealing with fish, either farm raised or wild caught. Also, aquaculture requires the use of fewer chemical and antibiotic inputs and fewer pounds of protein in feed as compared with the production of meats such as poultry, pork, or beef.5

Government Marine Conservation
The Magnuson-Stevens Fisheries Conservation and Management Act, passed by Congress 36 years ago, is dedicated to the stewardship of living marine resources through science-based conservation and management and the promotion of healthy ecosystems in the US federal waters (3 to 200 miles offshore). The act is managed through National Oceanic and Atmospheric Administration (NOAA) Fisheries. Through its scientific monitoring, NOAA establishes fishing catch levels in US water, and it has the authority to enforce these catch limits on fishing vessels, docks, and ports. It also oversees, monitors, and enforces the standards for US aquaculture.6

NOAA is the agency that “conserves, protects, and manages living marine resources to ensure recreational and economic opportunities for the American public,” says Katie Semon, NOAA FishWatch program manager. “With our recent FishWatch website upgrade, we’re also focusing on providing consumers with science-based information so they can make smart sustainable seafood choices.”

FishWatch aims to educate consumers about the complex science, management, and process of actively sustaining the seafood supply. “Because the US has rigorous management standards and closely monitors its fishing and aquaculture operations, when you see the term ‘US seafood product,’ it implies that the fish or shellfish is sustainably harvested,” Semon says. “So buying US wild-caught or farmed fish is an excellent sustainable choice.”

Other Ways to Source Sustainably
Eighty-five percent of the seafood Americans eat is sourced internationally. More than one-half of it is wild caught and about one-half is sourced (wild and farmed) from southeast Asia.7 For many US consumers, this raises serious health and sustainability concerns. Eco-labeling using third-party certification is one way to assure the consumer that a particular fish is safe and sustainable. Certification programs seen in the United States include the Marine Stewardship Council (MSC), Global Trust for wild-caught fish, Global Aquaculture Alliance (GAA), Best Aquaculture Practices, and Global Good Aquaculture Practices (Global GAP) for farmed fish. Friends of the Sea certifies both wild and farmed fish. To be considered effective, these systems must include three components: science-based standards set by an advisory board of stakeholders that include marine biologists, fishermen, and/or industry; a third-party auditing body that measures against the standards; and a certifying body that manages the certification based on annual and surprise random audits.

Another way seafood is vetted for sustainability is by marine conservation groups such as Monterey Bay Aquarium, Sea Choice, the Environmental Defense Fund, and the Blue Ocean Institute that develop a series of environmental criteria to evaluate whether a fish or fishery is sustainable. Their assessments often are condensed into seafood shopping guides with an “avoid” or “green” list of fish. “In the Blue Ocean Institute seafood assessment, we look at five criteria: fish species life history, abundance, habitat quality and gear impact, management, and bycatch to rate a fish and recommend if it should or shouldn’t be purchased,” McLaughlin says. (See the sidebar for additional pocket guide information.)

Heart of the Controversy
When it comes to seafood, Americans have a very limited palate. In fact, 90% of all the seafood we eat is limited to 10 species: shrimp, canned tuna, salmon, tilapia, pollock, catfish, crab, cod, pangasius, and clams, in descending order of consumption.8 Six of these most popular fish are sourced from imported aquaculture and rate poorly or as fish to avoid on most, if not all, marine conservation shopping guides. While the guides offer greener alternatives, they generally cost more—perhaps beyond the price point of the average US household. Will people really switch to a different green list fish or will they opt for beef, chicken, or pork—foods with an even higher environmental cost?

Other players in the seafood industry have a different perspective. Gavin Gibbons, a spokesperson for National Fisheries Institute, says, “One could reasonably say that the vast majority of the farmed fish Americans consume now has a very good sustainability story. Of the 10 most popular fish, most shrimp, salmon, tilapia, and pangasius are raised by aquaculture practices that are certified by trusted third-party verification programs.”

When asked specifically about one of the most controversial farmed fish species, salmon, Gibbons says, “It’s time to move out of the wild vs. farmed paradigm.” He explains that “the wild salmon fisheries couldn’t fill the year-round demand for salmon alone. Americans consume 350 million tons of salmon annually, and wild stocks can only sustainably supply about a third of what we consume. If Americans ate only wild salmon, the pressure on wild salmon populations would be tremendous.”

Wild and Farmed
A common misperception is that wild-caught fish is the better environmental seafood choice, and that aquaculture is environmentally damaging or polluting. But when it comes to seafood, it’s never a simple comparison. Worldwide, many wild-fishing harvests have reached their peak capacity, and illegal, unreported and unregulated (IUU) fishing threatens global seafood supplies. “NOAA is engaged in a global effort to combat IUU fishing, and in the United States we already have measures in place to restrict port entry and access to port services to vessels included on the IUU lists of regional fishery management organizations of which the United States is a member,” Semon says.

Aquaculture also has its issues. Fish are raised in contained areas in either open or self-contained systems, causing concern with regard to chemical input, disease and parasites, feed sourcing, escapes, and nutrient loading that can have severe environmental consequences if not monitored and carried out according to set standards. But as Peter Redmond, vice president of development for GAA, explains, “Global Aquaculture Alliance has stringent standards in four areas: environment, social welfare, farm-to-processor traceability, and food safety.” GAA certifies aquaculture farms, hatcheries, feed mills, and seafood processing plants. “Thirty percent of farms or processors seeking certification fail to meet our requirements on their first third-party audit and can’t be certified.”

Redmond stresses the need to have high yet attainable standards so that “it brings suppliers in and gets them on a path to continuous improvement.” He also points out that “the growing global demand for seafood can be met only through aquaculture, and third-party certification is the only responsible vehicle to let it grow and manage it in a very effective and positive way.”

Matthew Thompson, senior conservation associate and aquaculture specialist with the New England Aquarium, says that “responsibly sourced, sustainable aquaculture is a long-end game. It’s a gradual, continuously improving process pushed forward by innovation, new technology, and learning from past mistakes.”

Thompson says a successful strategy in moving the sustainable seafood agenda forward is one that his organization has with its industry partners: restaurant and grocery store chains. “We provide the science-based expertise to help our partners evaluate the issues and trade-offs that ultimately leads to more responsibly sourced seafood decisions for their company and the consumer.”

What RDs Can Do
Sustainable seafood sourcing is complex, nuanced, and fraught with controversy. But the bottom line is that eating more fish has real health benefits, and dietitians should inspire their clients to do so. There are many misconceptions about farmed and wild-caught fish, but both are healthful choices and can be sourced sustainably and economically. If you seek third-party assurance that your choice of fish is sustainable, look for eco-labeling from the MSC, the GAA, Global-GAP, or others. Nevertheless, there’s a growing trend in the supermarket industry to source sustainably at the corporate level so customers don’t have to worry about it. Ask your grocery store’s seafood manager about the seafood sourcing policy.

Not all stakeholders from NOAA, marine conservation groups, third-party certification programs, and the fishing industry agree on any single definition of seafood sustainability. While pocket guides with good-fish, bad-fish lists play an important role in raising awareness about the environmental impacts of personal choice, they present only one side of a complex issue. When choosing fish and seafood responsibly, dietitians can tell clients to rely more on third-party certification or the country of origin when selecting seafood.

Here are other recommendations from some of the experts:

 • Choose a different fish variety. “Branch out and try a fish you haven’t eaten before,” Semon says. “This helps build a market for abundant but underutilized fish, such as scup.” She also recommends that those living near the coast “look for what’s local and seasonal.” Another tip: “Take advantage of what’s fresh in the marketplace rather than going shopping with a specific fish in mind, [and] use the FishWatch.gov website to learn about the fish in your grocery store and on the menu at your favorite restaurant,” Semon says.

Be specific with clients. “Nutrition professionals should use this as an opportunity to provide clarity by teaching about the environmental impacts [of eating overfished seafood] and offer suggestions for healthful ocean-friendly food choices,” McLaughlin says. Her win-win suggestions for good-for-you, good-for-the-fish, and good-for-your-pocketbook choices include “canned Alaskan salmon. It’s accessibly priced and easy to incorporate into salads or casseroles.”

When eating out or cooking at home, McLaughlin recommends choosing blue mussels. “These bivalves actually filter the water, and the net result is improved water quality. They’re also rich in omega-3 fats, magnesium, and iron.” Sardines are another favorite. “They’re great sources of omega-3 fats and very economical. Try adding lemon juice to cut back on the strong flavor,” she says.

Thompson and Heather Tausig, associate vice president of conservation at the New England Aquarium, say, “Bluefish, Pacific halibut, and sardines are on our list of ocean-friendly wild-caught seafood, along with many farm-raised options, including bay scallops, mussels, oysters, barramundi, and rainbow trout from the US, and Arctic char from Iceland.”

But most importantly, Tausig says, “We encourage nutrition professionals and consumers to continue asking where and how their seafood is sourced. This prevalent voice in the marketplace helps identify the best players, set new benchmarks, and pushes the sustainable seafood movement forward.”

— Sylvia Geiger, MS, RD, is a freelance writer, blogger, and lecturer in the department of nutrition and food sciences at the University of Vermont. Her blog at SeafoodRD.com adds the RD’s voice to the conversation about seafood and balancing nutrition, health, and sustainability.


1. Questions & answers about dioxins and food safety. US Food and Drug Administration website. http://www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/DioxinsPCBs/ucm077524.htm. Updated February 17, 2012.

2. Dioxins in the food chain: background. US Department of Agriculture website. http://www.aphis.usda.gov/animal_health/emergingissues/downloads/dioxins.pdf. Accessed April 9, 2012.

3. Fish consumption advisories. US Environmental Protection Agency website. http://www.epa.gov/hg/advisories.htm. Updated February 7, 2012.

4. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA. 2006;296(15):1885-1899.

5. Hall SJ, Delaporte A, Phillips MJ, Beveridge M, O’Keefe M. Blue Frontiers: Managing the environmental costs of aquaculture. The WorldFish Center 2011; page 49. Penang, Malaysia. http://www.worldfishcenter.org/resource_centre_WF_2818.pdf. Accessed April 9, 2012.

6. US Seafood Facts. National Oceanic and Atmospheric Administration website. http://www.fishwatch.gov/wild_seafood/in_the_US.htm. Accessed April 9, 2012.

7. Per capita fish consumption in the United States 2004-2008. AboutSeafood.com website. http://www.aboutseafood.com/about/about-seafood/statistics/what-capita-consumption-fishseafood. Accessed April 9, 2012.

8. Seafood choices. SeafoodHealthFacts.org website. http://seafoodhealthfacts.org/pdf/seafood-choices-overview.pdf

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