Range Minimu Query: Given an array A[1,n] of n ordered objects (such as numbers), a Range Minimum Query (or RMQ) from i to j asks for the position of a minimum element in the sub-array A[i,j]. RMQs can be used to solve the lowest common ancestor problem.
The reasons that we do not eat or recommend shellfish are very similar. Shellfish are bottom feeders and feed on parasites and dead skin, many times from dead animals. They do not have appropriate digestive and filter systems to purify toxins and parasites from their body and flesh.
It sounds like you're doing everything you can to prepare the fish and chips the best way possible. Like the others have said, fish and chips aren't bad if they're eaten in moderation. Don't let other people make you feel guilty just because some people can't control themselves and eat fried food too often. It's not your responsibility to monitor what they eat or how often.