Gout patients do need to control a high-purine diet, but they need to control high-purine food. Seafood is a general term that covers everything and cannot be generalized. Some seafood contains essential nutrients for human body and cannot be completely banned.
People with gout should avoid high-purine seafood such as salmon, sardines and octopus, but eat low-purine seafood such as bass, eel and crayfish.
Low-content seafood is fine to eat. But if you have gout, it's best not to eat too much, because too much can worsen gout symptoms as well.