Eat all the salmon you want, but limit your amount of salmon shark, the Alaska Section of Epidemiology (part of the Division of Public Health) said when it recently updated its safe seafood consumption guidelines.

The Section of Epidemiology, in partnership with the Alaska Department of Environmental Conservation, started testing Alaska seafood for toxic heavy metals, such as mercury, and other pollutants, such as pesticides, back in 2001. The main reason for the research was to determine safe levels of seafood consumption for pregnant women, nursing mothers, infants, and others. According to the Alaska Dispatch News, the research involved testing fish, and using human hair samples to see how the heavy metals moved from species to species.

The Division of Public Health Division recommends eating fish at least twice a week. Medical research shows salmon are high in omega 3 fatty acids, which are believed to improve cholesterol and fight heart disease. Many types of Alaska seafood also are part of the traditional Alaska Native diet.

The good news is Alaska’s five salmon varieties (chinook/king, sockeye/red, coho/silver, chum/keta/dog, and humpy/pink) all tested as safe for everybody, with no limitations for pregnant women or others, as did halibut smaller than 40 pounds and Alaska pollock (commonly found in fish sticks and fast food fishburgers). This year’s expanded testing increased the number of safe-for-all species to 23 from 11 in 2007 (see chart above for complete list).

However, there were some seafood species where the Office of Epidemiology suggests consumption limits. Alaskans should use a point system, where people can eat up to 12 points a week (the safe species get zero points), with points based on six-ounce portions. Halibut (40-80 pounds), lingcod (35-40 inches) and lake trout are worth three points. Halibut (80-140 pounds), lingcod (40-45 inches) and longnose skate are worth four points. Halibut (140-220 pounds) and yelloweye rockfish are worth six points. Halibut (220 pounds or larger), lingcod (45 inches or longer), salmon shark and spiny dogfish are worth 12 points and should only be eaten once per week.