Application of risk analysis to genetic issues in aquaculture

摘要

In this review and synthesis, I explore the application of risk analysis to genetic harms posed by aquaculture, noting significant work to date and identifying areas where work is still needed. Harms posed by culture of a stock of aquatic organisms relate to chains of events occurring after an escape or release from a culture system. Direct genetic harms will flow from the cultured stock interbreeding with reproductively compatible populations in the receiving ecosystem, and could include loss of adaptation in natural populations, introgression of new genetic material into species' gene pools and, in the extreme case, loss of locally adapted populations. Risk assessment is an estimation of the likelihood of the occurrence of genetic harm becoming realized following exposure to a genetic hazard. The likelihood of harm being realized given exposure to a hazard is difficult to quantify with current knowledge, and we might often be restricted to evaluating risk qualitatively on the basis of: (1) the species at issue, (2) the effect of genetic background or improvement on the net fitness of the animal in the receiving ecosystem at issue and (3) the stability and resiliency of receiving community. Should distribution and production of a cultured stock pose unacceptable genetic harm to a population in the receiving ecosystem, the question then turns to design, selection and implementation of a programme of actions to minimize risk. Effective communication of principles and application of risk analysis is needed to organizations in both developed and developing countries.