Some of that fresh Gulf seafood is unsafe to eat due to high levels of mercury.  Texas A&M Dr. James Simons says they're looking for the source.

"A lot of it comes from atmospheric deposition, which comes from coal-fired power plants and things like that.  Of course you have spot contamination like the Alcoa plant that dumped a lot of mercury  into Lavaca Bay many years ago."

Caroline Mann with the State Health Department says women of childbearing age and all children are advised not to eat nine species of fish, including shark, mackerel, and swordfish. 

"Testing revealed that the mercury concentrations in some of the fish exceeded health guidelines."

Even adult men and women are urged to limit their intake.