Seafood is one of the least-consumed protein sources in the United States, which is odd because it's readily available, quick to cook and very nutritious.

So, I wondered, what's getting in the way of us enjoying seafood more often?

Quite simply, people are confused about what to buy. Environmental sustainability, mercury, PCBs, Omega-3, farmed vs. wild — these are the seafood buzzwords. They add to consumer confusion at the grocery store, and many people just give up and buy chicken instead.

Yes, it's confusing. But because seafood is so nutritious, I wanted to learn how to make the best choice. Here's where my journey took me and what I will be buying for dinner tonight.

Sustainability

Seafood is a term that encompasses fish and shellfish — so everything from canned tuna to fresh tilapia to lobster is considered "seafood."

"Up to 500 different species of seafood are sold in the U.S., but just 10 types make up 90 percent of what we consume," says Linda Cornish, executive director of the Seafood Nutrition Partnership. The top three? Shrimp, canned tuna and salmon.

This unwillingness to experiment with something new is a problem. Eating only a few species, Cornish says, leads to overfishing and unsustainable seafood supplies. The solution is to buy sustainable-caught seafood, which has been harvested in ways that protect the species and preserve the environment.

"Ask your fishmonger, grocer or restaurant about their buying practices," says Cornish. "Eighty percent of the North American grocery and food-service markets are working with the Conservation Alliance for Seafood Solutions to support sustainable seafood practices."

When you shop, look for the Certified Sustainable Seafood logo from the Marine Stewardship Council (MSC). It's found on fish that are caught with minimal environmental impact to ensure a sustainable fish supply for future generations. And download the Seafood Watch app from the Monterey Bay Aquarium in California, which lists sustainable seafood choices and indicates which species to avoid.

"Buying sustainable seafood is one of the single most powerful levers we have as consumers — to help protect our oceans, our food and our planet," says registered dietitian Kate Geagan, a sustainability expert known as America's Green Nutritionist.

The bottom line: Recommending one specific fish is neither realistic nor sustainable.

 

Contaminants

Do you avoid seafood for fear of contaminants, such as mercury and PCBs? Those fears are largely unfounded, experts say.

"One thing not to do is move away from the fish counter because you're in fear, which is certainly understandable with all the information swimming around," says Geagan.

Many studies have concluded that the benefits of the Omega-3 fats in seafood outweigh the potential harm from contaminants. The exception: There are specific guidelines for pregnant women and children, for whom mercury exposure poses a greater risk. They should avoid tilefish, shark, swordfish and king mackerel.

"Seafood in the U.S. is very safe to eat," says Cornish. "The FDA protects the safety of our food supply through a program called Hazard Analysis Critical Control Point, which is a management system that controls biological, chemical and physical hazards from every point from production through to consumption."

Cornish says we can trust commercially available seafood in grocery stores and restaurants but need to be wary of fish caught for sport. "Before you eat fish that you've caught yourself, check health advisories for local waters."

If you are concerned about any amount of contaminants, Geagan suggests buying smaller-size fish. "Try seafood that's lower on the food chain, like sardines, mussels and clams. They don't have as much PCBs and mercury, which are more concentrated as you move higher up the food chain to larger fish."

 

Wild vs. farmed

Farmed seafood, also known as aquaculture, is a method of commercially raising fish. Wild fish stocks are not as abundant as they once were and can't meet consumer demand. More than 50 percent of the seafood we currently eat comes from aquaculture.

Concerns about farmed fish include the level of PCBs, treatment of workers, water pollution, disruption of ecosystems and the effects on wild fish if farmed fish escape their pens.

"Twenty years ago, practices were not the best, but it's better now," says Cornish.

More checks and balances are in place. The Aquaculture Stewardship Council (ASC) is a nonprofit organization that oversees fish farming. They place a logo on products from companies that use best practices to preserve the environment, prevent harm to wild fish, use good quality feed and care about their workers' health and safety.

One way to balance sustainability, contaminants and health is to check the Environmental Defense Fund's Seafood Selector before you shop. It groups fish into categories ("best," "OK" and "worst" choices) based on sustainability, Omega-3 and mercury content.

The website currently shows 85 options in the "best" category, leaving many exciting possibilities for dinner.

— Registered dietitian Cara Rosenbloom is president of Words to Eat By, a nutrition communications company specializing in writing, nutrition education and recipe development. She is the co-author of "Nourish: Whole Food Recipes featuring Seeds, Nuts and Beans."