Description

• Fish have evolved over millions of years to become adapted to their environments. Some fish live in salt water, some in freshwater and still others can tolerate both. One way of categorizing fish is by their tolerance to salinity, or the amount of salt in the water. Some saltwater fish such as tuna can tolerate only very minor shifts in salinity and are referred to as stenohaline species. Saltwater fish that are able to tolerate a wider range of salt concentration, such as eels, salmon, striped bass and flounder, are called euryhaline fish.
  
  

Ecological Groupings

• An alternate approach to the categorization of saltwater fish species is to divide them into three groups depending on where they live. Littoral fish are fish that live relatively close to the shoreline and include redfish, speckled trout, southern flounder, hardhead catfish, Atlantic stingray and bull sharks. The second group includes fish such as jewfish and red snapper, and are known as reef fish for their tendency to live around natural or man-made reefs. The third group is known as pelagic fish. These offshore migratory saltwater fish species includes wahoo, cobia, Spanish mackerel, white marlin, blue marlin and blackfin tuna.
  
  

Game Fish

• Yet another method of classification is to divide saltwater fish species into game and non-game fish. Game fish are most sought after by professional anglers and regulations are often placed on these species to avoid overfishing and subsequent endangerment. Examples of game fish are sailfish, longbill spearfish, cobia, broadbill swordfish, blue marlin, snook, spotted sea trout, king mackerel, redfish and Spanish mackerel. Sharks such as the bonnethead shark, sandbar shark, hammerhead shark and shortfin mako are also considered game.
  
  

Non-game Fish

• Non-game saltwater fish species are still fine for sport fishing and for food. Non-game fish are considered to be in sufficient quantities, and the species are stable enough so that regulations that limit fishing for them are not considered necessary. These fish include the dolphin fish (mahi mahi), jewfish, red snapper, sheepshead, southern flounder, hardhead catfish, black sea bass, crevalle jack, blackfin tuna, black drum, Atlantic stingray and Atlantic croaker.
  
  

Endangered Species

• Despite the conservationists' and regulatory agencies' best efforts, there are many saltwater fish species on the endangered animals list. Overfishing, climate changes and pollution can all contribute to the decline in population of any one species. Wild salmon species such as chinook, coho and cockeye are all on the endangered list. Angel sharks, steelhead trout, Russian sturgeon and smalltooth sawfish also are listed as endangered.