Really though, I just looked at your link and that's insane. Where is all the pollution coming from? It basically limits consumption to 8oz./per month for fish coming from the Gulf.
WHERE DO CONTAMINANTS COME FROM?
Contaminants end up in water in a variety of ways:
Industrial and municipal discharges, agricultural practices, and storm water runoff can all deposit harmful substances directly into the water.
Rain can wash chemicals from the land or air into streams and rivers. These contaminants are then carried downstream into lakes, reservoirs and estuaries.
Fish take in these substances in several ways, and their contaminant levels depend on factors like species, size, age and location.
Mercury, for example, is naturally converted by bacteria into methylmercury. Fish absorb methylmercury mostly from their food, but also from the water as it passes over their gills. Generally, larger and older fish have had more time to bioaccumulate mercury from their food and the water than smaller and younger fish. In addition, large predatory fish (like sharks and swordfish) near the top of marine food chains are more likely to have high levels of mercury than fish lower in marine food chains due to the process of biomagnification.
Fish can also absorb organic chemicals (such as PCBs, dioxins and DDT) from the water, suspended sediments, and their food. In contaminated areas, bottom-dwelling fish are especially likely to have high levels of such toxins because these substances run off the land and settle to the bottom. These organic chemicals then concentrate in the skin, organs and other fatty tissues of fish. Wild striped bass, bluefish, American eel, and seatrout tend to be high in PCBs, since they are bottom-tending fish often found in contaminated rivers and estuaries.
http://seafood.edf.org/common-questions-about-contaminants-seafood