Smaller fish—sardines, anchovies, farmed trout, fresh tilapia, arctic char—and bivalves such as scallops, clams, and oysters don't build up as many contaminants as do the large carnivores.
These fish are also safe to eat at least once per week: anchovies, clams, Dungeness crab, king crab (U.S.), snow crab, Pacific cod, crawfish (U.S.), Atlantic herring (Canada/U.S.), spiny lobster (Australia/Baja/U.S.), Atlantic mackerel, blue mussels, farmed oysters, Alaska pollock, canned pink/sockeye salmon, sardines, ...
1. Pufferfish (some species are also called toadfish) have been given the title 'Most Poisonous Fish' and have also been labeled the second most poisonous vertebrate in the world. The toxin responsible for ranking this fish so high in the “danger zone” is called tetrodotoxin.
Choose lower-mercury fish and seafood, such as salmon, shrimp, cod, and sardines. Avoid higher-mercury fish, such as tilefish from the Gulf of Mexico, shark, swordfish, and king mackerel. When choosing fresh fish, look out for fish advisories for those particular streams or lakes.
The Dietary Guidelines for Americans states that to consume those higher amounts, children should only be fed fish from the “Best Choices” list that are even lower in mercury – these fish are anchovies, Atlantic mackerel, catfish, clams, crab, crawfish, flounder, haddock, mullet, oysters, plaice, pollock, salmon, ...
Sardine and swordfish are contaminated with toxic heavy metals at very high levels which are exceeding the thresholds established by the Algerian and the European health authorities.
More than 400 species have been implicated in ciguatera poisoning (Randall, 1980), but the fish most commonly implicated include amberjack, snapper, grouper, barracuda, goatfish, and reef fish belonging to the Carrangidae (Table 4-2).
Low in Toxins
Because sardines eat smaller organisms like plankton and don't live as long, they contain hardly any of these toxins.
Making the “do not eat” list are King Mackerel, Shark, Swordfish and Tilefish. All fish advisories due to increased mercury levels should be taken seriously. This is especially important for vulnerable populations such as young children, pregnant or breastfeeding women, and older adults.
1. Cod. Cod is often considered one of the best white fish and commonly featured in recipes like fish and chips due to its dense, flaky texture. In addition to being relatively low in calories, cod is an excellent source of protein, selenium and vitamin B12.
White fish such as hoki or tarakihi has lots of omega-3, and oily fish such as salmon or tuna has even more. We recommend choosing products with 200mg or more omega-3 per 100g.
Eat panfish, such as bluegill, perch, stream trout, and smelt. They feed on insects and other aquatic life and are less likely to contain high levels of harmful pollutants. Eat fewer fatty fish, such as lake trout, or fish that feed on the bottoms of lakes and streams such as catfish and carp.
HERRING. These silvery fish are not only affordable and full of omega-3s, but herring has minimal mercury content, making it one of the cleanest and safest ocean fish to eat, says Derocha.
Cooking or soaking fish cannot eliminate the contaminants, but heat from cooking melts some of the fat in fish and allows some of the contaminated fat to drip away. Broil, grill or bake the trimmed, skinned fish on a rack so that the fat drips away.
They found that while boiling fish does reduce the toxin—by about 18 percent, in fact—steaming the filets reduced it even more, to a rate of about 26 percent. What's more, biotoxins also pass into the steaming water and avoid our bodies almost entirely—which is a very good thing.
Fish and shellfish like salmon, shrimp, tilapia, and crab are great choices to get your recommended services of fish without risking heavy metal poisoning. Fish like king mackerel, marlin, shark, swordfish, and bigeye tuna have the highest amount of heavy metals and should be avoided if possible.
Summary. Sardine is richer in Vitamin D, Calcium, Iron, and Phosphorus, while salmon is significantly richer in Vitamin B6. Sardine also contains considerably less cholesterol and sodium, while salmon has less calories because it contains more water and less fats.
Species of fish that are long-lived and high on the food chain, such as marlin, tuna, shark, swordfish, king mackerel and tilefish contain higher concentrations of mercury than others.
In most fish, the levels are very low. However, some varieties contain high levels of mercury due to their feeding habits or surrounding environment. Commercially sold fish that may contain high levels of mercury include shark (flake), ray, swordfish, barramundi, gemfish, orange roughy, ling and southern bluefin tuna.
Summary. Fish that contain high levels of mercury include shark, ray, swordfish, barramundi, gemfish, orange roughy, ling and southern bluefin tuna.