With health and customers with fish allergies in mind
I would categorize fish as a health “superfood”. Fish, especially the colder water fish such as salmon, tuna, herring, etc., offers powerful omega-3s, along with a dose of high quality protein plus potassium, some B-vitamins and it’s also a rare natural food source of vitamin D.
Eating fish (non-fried) two to three times a week is a popular recommendation from various health experts and agencies. This weekly healthful habit has been associated with lowering the risk of some cancers and heart disease, especially if it is eaten as a replacement for red meat or foods high in saturated fat.
With customers becoming more and more aware of the possible health benefits of fish, fish has a definite place on the menu in restaurants across the country. But fish and shellfish (crustaceans) are both in the “top 8” most common allergens in the United States, so it’s important for restaurants to keep the following tips in mind.
10 Tips for serving customers with fish/shellfish allergies
•    Customers with fish allergies should generally avoid seafood restaurants, due to concerns about potential cross contact in the kitchen during food preparation and service. (Fish protein can become air born in the steam released during cooking.)
•    Asian cuisine is the second most challenging type of restaurant for people with fish allergies. Fish and shellfish are featured in many popular dishes and additionally fish sauce is a common flavoring ingredient in dishes and sauces.
•    Allergies to shellfish include crustaceans (crab, crawfish, krill, lobster, prawns, shrimp and scampi), and mollusks (abalone, clams, mussels, octopus, scallops, squid, etc.). People are most commonly allergic to the crustacean varieties of shellfish, but customers may avoid mollusks as well to be extra cautious.

•    Besides eating the actual fish, products or other foods containing fish includes fish sauce, Worcestershire sauce, fish stock, fishmeal, Caesar salad, caviar, anchovies, roe, some salad dressings, shark fin and cartilage, surimi, sushi and sashimi, etc.

•    Prepare dishes that contain fish/shellfish in a particular section of the kitchen if possible to keep the potential for cross contact to other dishes to a minimum.
•    Use a separate fryer to fry all of your fish and shellfish if possible. If you have one fryer and fried fish and shellfish are on your menu, anything fried in the oil will contain fish/shellfish protein (even the French fries).
•    Use a separate grill to grill all of your fish and shellfish if possible. If you have one grill and fish/shellfish is cooked on that grill, anything cooked on the grill has had contact with fish/shellfish protein.
•    Having fish or shellfish as an add-on option or a substitute option for chicken can give your customers allergic to fish/shellfish more menu options. They can order salads or pasta dishes, for example, with chicken instead of fish or shellfish.
•    When your staff is preparing dishes for patrons that identify themselves as having an allergy to fish/shellfish, ideally the staff should use clean cookware and utensils, gloves, cutting boards etc.…when preparing the dish to minimize potential for cross contact. Once the dish is prepared, cover it immediately and transport it covered, to keep it away from foods that may splatter or transfer steam that contains fish/shellfish protein.
•    Train all of your staff on these points and remind that that if they make a mistake, they cannot just remove the allergen (in this case fish or shellfish) from the salad or plate. Even a small amount of the allergen left can be enough to cause a severe allergic reaction.