Coastal Zone

Stock enhancment

Declining fish populations around the world demand a change in current fishing practices. Along with the change in fishing practices, many recommend a technique called Stock enhancement. Stock enhancement is the practice of culturing juvenile fish and then releasing them into the wild to help regenerate declining fish populations.

The principle of hatchery based stock enhancement is not new and was practiced in the later part of the 1800's and during the first 50 years of the 1900's. The use of hatcheries to increase wild fish populations was discontinued in 1950 because after over fifty years of practice no evidence of increased yeild resulting from the technique were detected. Another problem of the early stock enhancement projects was the inability to culture marine fishes beyond their early larval and juvenile stages. In recent years, new technologies, such as benign fish tags and better cultivation have revitalized interest in stock enhancement.

One of the most important obstacles facing stock enhancement is the ability to determine if the project has succeeded in increasing local fish populations, or if it had no effect or a negative one. Early hatchery projects had no means of tagging the juveniles they released into the wild to monitor their survival and reproductive rates. Part of the revival of stock enhancement is the result of new technologies such as electronics that have allowed the creation of benign tags that monitor the fishes activities without hindering them.

We now have the tools to create a potentially successfull stocking program. What is lacking not is the administrative and management infrastructures necessary to develop and maintain such a project. There are ten components that a stocking program must address to create and maintain an effective stocking system. The components are:

Determining the species to be enhanced
Developing a set of objectives and goals
Developing a system of quantitavely determing the success of the program
Avoiding the introduction or maintainance of undesired genetic effects
Disease and Health control of the enhanced species
Determing the ecological, and biological implications of such a project
Developing the ability to identify and monitor stocked fish and their impacts
Developing an emperical culture and release system that optimizes the survival rate of released fish
To identify the economics and regulations that may affect or be affected
To create a management capable of adapting to changing technologies, techniques, and trends

Stock enhancement in this modern form to produce commercially viable fish stocks that will replenish diminished natural wild stocks is currently being tested in Hawaii. The Haiwain studies indicate that stock enhancement can become a vialble alternative to help replenish the oceans fish supplies. Other studies are also underway, but at the time of this writing, the results of the projects have not been determined.

With the proper care of the environment and current wild stocks, hatchery based stock enhancement offers the potential ability to significantly increase the rate of recovery of decimated species of fish. Care must be taken to protect the existing stocks as work is done to restore them; under the wrong management there is the potential to damage the wild stocks through stock enhancement.