Maintaining genetic diversity through management
Genetic diversity provides the basis for improving aquaculture production. However, aquaculture practices can affect genetic diversity at many levels by changing species, communities of fish and ecosystems. Risk assessment and monitoring systems are needed to protect these genetic resources. For example, simple records of management of wild genetic resources are useful as a benchmark for measuring later impact. Information databases are needed on aquatic genetic resources for both farmed and wild species. Aquaculture stocks or stocks for culture - based fisheries can be managed within the culture facility to avoid inbreeding and maintain stock integrity by not hybridizing different stocks, strains or species and by transferring the minimum amount of genetically different stocks. This is assisted by regular assessment of genetic diversity using laboratory analysis.
Natural levels of genetic diversity can be maintained by reducing the movement of diverse populations or using genetic technologies to culture non - reproductive organisms. Public education on the safety and ethics of genetic technologies is needed to make sure aquaculture products are acceptable to consumers.
Individuals and groups need to be aware that there is already legislation in many countries that governs the use and transport of species outside of their natural range. For example, the ICES/EIFAC Code of Practice and the Nuisance Species Protection Act USA are intended to control introduced species.
Several sets of regulations govern the use, transport and release into the environment of genetically altered organisms. These include the:
Directives of the European Union;
Performance Standards of the USDA, and the
ICES Code of Practice
The Convention on Biological Diversity (CBD) has prepared biosafety rules for the safe use of genetically modified organisms. Other sources of information are databases on international introductions of aquatic animals and aquatic animal pathogens, usually available on the Internet. International codes of practice need to be adapted for developing countries.
Guaranteeing quality, performance, ecological safety, seed and broodstock
Aquaculture agencies can promote responsible practices for genetic improvement of broodstocks and the production, sale and transport of eggs, larvae or fry or other living organisms. Governments can help by developing guidelines and regulations on acceptable genetic technologies and breeding practices. International codes of practice may include plans for development of national guidelines and procedures on the use of genetically altered species.
Few fish farmers have the training and experience needed to use genetic technologies without loosing genetic fitness. Farmers can maintain a high level of genetic diversity by: breeding as many fish as possible, using brooders and eggs from the entire spawning season, avoiding full - sibling or parent - offspring mating and keeping careful records of production practices.
Aquaculture can help protect and improve stocks of endangered species. As a conservation measure, endangered species can be kept temporarily in hatchery and culture facilities while efforts are being made to restore the natural habitat or reduce or remove threats to the species. Governments can play a key role in supporting these efforts by exploring genetic technologies to identify genetically compatible or suitable broodstock, determining the taxonomy of the endangered species and by making sure there is a good supply of gametes by freezing sperm (cryopreservation) from endangered or closely related species.
