The advisory does not restrict consumption of king mackerel under 37 inches. Health officials said the consumption advisory is a preventive measure. We're concerned primarily with children, females of childbearing age and anyone who regularly consumes the larger king mackerel. Mercury is a naturally occurring element that can be toxic when consumed by humans. Continual ingestion of methyl mercury, the compound found in the king mackerel, can harm the human brain and nervous system.
Young children are especially at risk.
The brain and nervous system in developing fetuses can be permanently damaged if pregnant females eat foods containing elevated levels of mercury. Mercury gets into the air and water from the natural weathering of the earth's crust, from the burning of garbage and fuels and from emissions from factories that use mercury. No specific source of the mercury in the gulf king mackerel has been determined. The advisory does not apply to canned mackerel, a different species of mackerel. Officials said the mercury content in gulf waters is negligible and that elevated mercury levels in the king mackerel are the result of accumulation along the food chain.