Can anyone tell me if there is a real concern about the mercury levels in Texas Gulf Barracuda and King fish?

Contact the TPW in Austin. They monitor mercury and other toxins in fish. Also ask about cigerterra(?) poison in barrcuda. I know this is a problem with cuda caught in some Mexico waters.

I am not an expert but, there are recommendations from TPWD about the consumption of large kingfish and it could also be that way for other large fish. The mercury contamination in kingfish is a result of them consuming fish which are carriers of mercury. And as the fish gets older and larger the concentration levels rise since the mercury is retained and not expelled from the body.

As far as the poison from eating barracuda, I was told that only the fish from the pacific side of mexico have it not the atlantic/gulf fish. I don't know for sure but, that is what I was told. I know that the deckhands on the boats out of Cancun keep barracuda that are caught while sportfishing to take home and eat.