Payson Roundup

A fish consumption advisory has been instituted for largemouth bass and channel catfish at Roosevelt Lake because recent samples of those specific species of fish collected at the lake showed elevated levels of mercury.

That brings the number of Arizona lakes with mercury consumption advisories to 14.

The consumption advisory is not directed at other fish, such as black crappie, bluegill, green sunfish and redear. The advisory does not apply to the use of the lakes for fishing, bird watching, swimming or other recreational uses.

Anglers should take simple precautions and follow the guidelines to limit your consumption of those specific species of fish caught at Roosevelt.

Mercury can accumulate in the tissue of fish through a process called bioaccumulation. Basically, it is a food-chain effect. Elemental mercury present in the environment is converted to methlymercury by bacteria. The bacteria are then ingested by other microorganisms which are then consumed by insects and baitfish. Health experts say those organisms likely have extremely low levels of mercury, and don’t pose a known health risk.

However, for each step up the food chain, as one organism consumes another, mercury levels become more and more concentrated. Therefore, large top-of-the-line predators can experience levels beyond the consumption threshold established by health officials.

The consumption guidelines are:

Roosevelt Lake — largemouth bass and channel catfish:

• Children under the age of six: No consumption

• Women of child-bearing age and children between 6-16 years old: One 8 oz. fish meal per month

• All other adult women: One 8 oz. fish meal per month unless a doctor supports a higher consumption rate.

• Adult men: Five 8 oz. fish meals per month