(CNN)We're all trying to make healthier choices, but when it comes to fish, is one type truly better than another? Nutritionally, there's no wrong choice when it comes to seafood as a food group.
What is the healthiest fish to eat? The best choices for you and the planet
"As an animal source, it has one of the lowest amounts of saturated fat in relation to protein," said Lourdes Castro, registered dietitian nutritionist and director of the NYU Food Lab. In addition to being a lean protein, seafood is high in D and B vitamins and minerals like iron, potassium and calcium.
Most crucially, seafood is high in omega-3 fatty acids, which are essential to the cellular makeup of our bodies and can help with our cardiovascular health and immune systems. Because the body can't produce its own omega-3s, all our intake must come from the food we eat.
"Our diets typically don't contain a lot of omega-3s," said Mary Ellen Camire, professor of food science and human nutrition at the University of Maine. Eating seafood twice a week is one surefire way to increase our intake of these fundamental fatty acids.
From a nutritional standpoint, salmon is the clear winner of the healthiest fish competition. "Fattier fish from cold water are a better source of omega-3s" than other sources, Camire said, and salmon is king when it comes to the number of grams of omega-3s per ounce.
The National Institutes of Health recommend that men consume 1.6 grams and women consume 1.1 grams of omega-3s daily, and one 3-ounce serving of nearly every variety of salmon surpasses that quota. Alaskan Chinook salmon (also known as king salmon), Coho salmon and sockeye salmon are three wild salmon species rated the highest in omega-3s.
Sustainability is the other part of the equation when it comes to calculating the healthiest fish -- for personal health, the health of fish populations and the planet overall.
"Today, there are environmentally sustainable sources both on the wild side and the farmed side," said Santi Roberts, senior science manager at the Monterey Bay Aquarium's Seafood Watch.
Farmed salmon are not only more sustainably managed than in the past but are jumping ahead in terms of omega-3s. "From a nutritional standpoint, it used to be that wild was superior to farmed," Castro said. However, Camire said that with advances in aquaculture, farmers can adjust the diet of their salmon to produce fish that have a higher ratio of omega-3s than their wild counterparts.
Sustainable aquaculture is also a proactive way for fisheries to address the effects of climate change. "There aren't enough fish in the ocean to feed everyone based on nutritional recommendations for seafood," Castro said.
Camire agreed. "Wild is a sexy idea," she said, but she questions how wild seafood from Alaska will fare over the next few decades. "In terms of us feeding billions of people and the climate getting hotter, we're going to have to do something differently."
Apart from salmon, there are other varieties of seafood that make the grade in terms of both personal health and planetary sustainability. Bivalves like oysters, mussels and clams are relatively high in omega-3s and a good choice from an environmental perspective, according to Roberts.
Unlike fin fish, bivalves don't need to be supplemented with feed when raised in a farmed environment; they take all their nutrients from the water surrounding them. They can also filter out impurities and offset waste entering the environment, which Roberts noted is often a problem with farmed seafood.
Camire also recommended US-farmed rainbow trout as a good alternative to salmon. "They don't have quite as many omega-3s as salmon do, but they're related," she said, and US fish farms must follow federal and state food safety regulations.
Tuna, while high in omega-3 fatty acids and a superior nutritional choice, is more challenging to source sustainably. Wild tuna populations have been decimated by overfishing, and the fish itself can be high in mercury.
Experts in both nutrition and sustainability don't think we should avoid eating tuna altogether, but it requires some research to make sure you're picking the most manageable option. "Avoid eating bluefin until we've seen significant improvement in management of those populations," Roberts said.
If you want to eat tuna, skipjack and albacore offer almost as many omega-3s and are the two species most frequently found in tuna cans. Roberts recommends looking for the phrases "pole and line caught" or "troll-caught" on the label.
Similarly, sardines and mackerel are high in omega-3s, but they are no longer recommended as sustainable options because of overfishing concerns for these species.
If you're overwhelmed by seafood labels at the fish market, that's understandable. But these days, apps and websites run by scientific and non-profit organizations can help you make the healthiest choices.
Seafood Watch, the ratings program run by Monterey Bay Aquarium, has been providing seafood buying recommendations based on sustainability standards for two decades. Its system is simple -- green is the best choice, red is an item to avoid -- and covers both wild and farmed options from fisheries worldwide.
"It's a dynamic and complex world -- what we try and do is to simplify it down, is to look for the green," Roberts said.