• States employ various methods to sustain fisheries for the future.Fishing image by Antonio Oquias from Fotolia.com
  
  Fishery management techniques are used to sustain fish in areas of heavy fishing and prevent total collapse of the fishery. Methods vary depending on the type of fish and the type of environment. For example, not all of the same techniques used to manage striped bass in the Chesapeake Bay can be applied to manage Hawaiian bottom fish off Pacific waters. The type of waters the fish live in, and the amount of fishing in the area play a vital role in which methods work best.
  
  

Annual Counting

• Fisheries use annual review of population or stock assessment to assess populations and give vital data on the fishery. In Oregon and Washington, the white sturgeon population is monitored closely using mark-recapture data. Sturgeon are tagged with small tags. Commercial fisherman and non-commercial fisherman are required to turn in the tags when a fish is recaptured. This data is used then to determine an estimated population based on the tags received and the proper methods needed to sustain the fishery.
  
  

Bag Limits

• Bag limits restrict the number of fish non-commercial fisherman take from the area. For instance, Hawaii has a bag limit placed on the amount of bottom fish fisherman can take. Fishermen can catch five onaga or ehu per trip. Another example exists in Oregon, where the salmon bag limit in Oregon is two daily. In California, white sturgeon have a daily bag limit of one. In all these areas, bag limits aid in sustaining the fishery.
  
  

Stocking

• One fisheries-management technique uses stocked fish enhancement through the use of hatcheries. Stocked fish are used in many areas of the country to replenish fish in high-use areas. For example, Nevada hatcheries produce 430,000 pounds of trout annually. Stocked trout are used in this state to replenish trout in lakes and reservoirs because these trout do not reproduce in lakes. Eighty percent of the fishermen fish lakes and reservoirs in Nevada. Stocking is expensive and uses up about 50 percent of the department's budget according to the Department of Wildlife of Nevada.
  
  

Size Limits

• Size limits play an important role in sustaining a fishery. A good example of size restrictions in use exists in California, where size limits were imposed on white sturgeon. A legal catch must fall in the range of 46 to 66 inches. Large sturgeon produce more eggs than smaller sturgeon. The large fish that are kept reproducing become fish factories that cannot be replaced by nature so quickly. Striped bass and blue crab in the Chesapeake Bay are other examples of fisheries that currently use size limitations to sustain both populations.