The pollution in Florida's Gulf alone,killed the population of tourism,thus killed fishing areas. I think the first thing you want when you go to a nice fish restaurant in Florida, is a nice meal. If you think of all the pollution in the area,your not going to want anything of the sort.
Yes, I think that coastal pollution in high-density fishing areas reduced American families' desire to purchase seafood, because we cannot be sure that the seafood is safe. We have to worry about high levels of mercury. We have to worry about other problems in the seafood. Pollution can make the fish sick, and us.
If I lived in an area close to the coastline, where I can see the ocean bringing in garbage. I would make sure I would not buy any local seafood. My state has nuclear waste draining into the ocean. We do not have to worry though, because there is not any fish around for people to catch.
Pollution has a very real impact on the seafood industry, but purchasing decisions are governed more often by other factors. For example, disgust of seafood may prevent buying habits, or the price may be prohibitive. At the same time, fish does not always say "came from x" on the label, so even if you know LA is polluted, the place this fish was caught might not be polluted.
The cost of fresh sea food from any area, not just polluted high density fishing areas, are causing the reduction in American families' desire to purchase seafood. The normal modern family can not afford the expensive prices of fresh sea food. Costs of fish are rising while the wages are all remaining the same. This makes it nearly impossible to regularly consume some things, fish included.