This was pulled off the Pensylvania DNR site pertaining to trout. I think the general precautions are pretty much the same. Seeing as how walleye have less fat than salmonoids, they may have less potential to store PCB’s?
Q. What are PCBs?
PCBs are polychlorinated biphenyls. These are a group of man-made chemicals that were used as lubricants and coolants in a variety of industrial and electrical products and applications, such as capacitors, transformers, turbines, etc. The manufacture of PCBs in the United States was discontinued in 1977. PCBs are very persistent, and even though their manufacture was discontinued more than 20 years ago, trace levels of PCBs remain throughout our environment. PCBs are a group of 209 individual chemicals, known as chlorinated hydrocarbons, that were marketed under various trade names. The most common name for PCBs found in the environment is Aroclor. Everyone is exposed to some PCBs, and they are found everywhere. They have even been found in penguins in Antarctica. There are several possible sources of exposure to PCBs including drinking water with PCBs, breathing air with PCBs and occupational health exposures. The most common source of exposure is from eating foods that may contain some level of PCBs. Such foods include fish, eggs, red meat, poultry, milk and cheese. Click here to see “PCBs 101” from the U.S. EPA.
Q. How should you clean and cook fish that might contain PCBs?
PCBs and most other organic contaminants usually build up in a fish’s fat deposits and just underneath the skin. By removing the skin and fat before cooking, you can reduce the levels of these chemicals.
One of the best ways to reduce your exposure, and get a more enjoyable meal, is to fillet the fish:
Prepare the fish by making a cut along the back, near the dorsal fin.
Cut the length of the fish, working toward the tail and belly–but don’t cut into the belly. Let the rib bones guide your knife blade to get the fullest fillets.
At the tail, don’t cut the fillet off. Guide the knife blade between the skin and the flesh.
Flip the fish over and repeat.
You can take other steps to reduce chemicals in the fish you eat:
Remove all skin.
Slice off fat belly meat along the bottom of the fish.
Cut away any fat above the fish’s backbone.
Cut away the V-shaped wedge of fat along the lateral line on each side of the fish.
Bake or broil trimmed fish on a rack or grill so the remaining fat drips away.
Discard any drippings. Do not eat them or use them for cooking other foods.