Yeah, the guys from Wisconsin. Give him a break. The state is 90% white (I'm not exagerrating)...er caucasian (I've never referred to myself as caucasian). He was curious, he got his answer.
^I don't think that's fair to assume. I live in Wisconsin and at least in my city there is a huge amount of diversity.
As far as the original question. I know at my local LFS I see a lot of different people come in and buy fish. They may be mostly white but other races are common. I guess I never really thought about it before.