You can find fresh seafood in a lot of places in Zhuhai. Wanchai or Xianzhou are probably the best places but really not worth worrying about. I found that most of the larger hotels were good. I particulary liked the Zobon which is now called the Lexington Plaza.
Zhuhai city is a large place but is strange in that there is no Zhuhai city area. Zhuhai consists of Gongbiei, Jida, Xianzhou and satelite areas like Wanchai and Doumen. There are the Imperial Hot Springs in Doumen (approx 25K out from the ferry port). There is alkso Ocean Spring Resort which is a huge five star resort in Pingsha Town 35K from the ferry port (this one has its own bus service to the port).