Pacific NW Albacore Tuna tests Lower in Mercury

Pacific NW Albacore Tuna tests Lower in Mercury

Mercury vs Omega-3?

(originally published at the OSU Seafood Lab website: Cannery Row in the 21st Century)

To eat or not to eat seafood, that is the question…

Fish absorb mercury from the environment through their gills and from their food. Some fish have more of this organic methylmercury in their tissues than others, depending on their environment and how far up they are in the food chain. A general rule of thumb is that the larger or older the fish, the higher the level of methylmercury in its flesh. A very large bluefin tuna or swordfish, for example, will tend to have accumulated relatively high levels of mercury.

Although all fish have trace amounts of methylmercury, most fish have less than 0.1 parts per million (ppm), well below the allowable levels of 1.0 ppm mercury content that the U.S. has set for fish and seafood products. To limit mercury consumption for children and for women of child-bearing age, the U.S. Food and Drug Administration says that it is safe to eat up to 12 ounces a week of low-mercury fish, avoiding some species such as shark and swordfish.

Locally caught Oregon salmon, shrimp, flounder, and oysters are very low in mercury. But up until recently, mercury content of tuna was averaged for all species, making no distinction between small, young albacore from the cold north Pacific and the much larger, older tuna from the warm south Pacific.

So OSU researchers sought to compare mercury content among all the major commercial species of tuna. They found that small, young albacore tuna caught off the Pacific Northwest coast have low mercury levels, below most commercial brands and below FDA guidelines.

Not only is locally caught albacore safely below thresholds for mercury, there is good evidence that eating it is beneficial to your health, according to Michael Morrissey, superintendent of the Food Innovation Center in Portland. Local albacore is high in omega-3 fatty acids, which have been shown to reduce the incidence of cardiovascular disease and improve brain health. One of those omega-3 fatty acids, DHA, found only in fish, is an important nutrient for infant vision and cognitive brain development.