Fisheries genetics - the application of genetic principles and methods to fisheries biology and management - has stimulated a resurgence of interest in the factors underpinning the dynamics and resilience of exploited species. Topics such as connectivity among marine populations, the spatial and temporal scale of population differentiation, effective population size, fisheries-induced evolution, and the analysis of adaptive variation in the wild, not only enhance our understanding of the mechanisms shaping fish abundance and distribution, but contribute conceptually to ecological and evolutionary theory. Whereas classical fisheries approaches focused typically on the factors driving short-term demographic changes in populations (“quantitative” change), genetic approaches examine the extent to which changes in the composition of populations (“qualitative” change) influence both short-term alterations in phenotypic traits and longer-term response to natural and anthropogenic perturbations.
Genetic analysis tools are used to assess DNA, the genetic material that comprises the genetic code of all living organisms. It can be obtained from very small tissue samples, and often from highly degraded material. It can be used to address three principal questions as illustrated below.
Fish symbols courtesy of the Integration and Application Network, University of Maryland Center for Environmental Science. Map: © European Union, 2010.
Three principal questions, relevant for fisheries management and conservation, which can be tackled by genetic identification approaches. a) What species? b) Where from? c) Wild or cultured?
Genetic species identification is shown here in the context of product authentication in a control and enforcement context but can also be used for fisheries management e.g. when performed on Ichthyoplankton. The genetic distinction between wild and farmed fish will become more relevant in the near future, due to the steep rise in aquaculture activity worldwide. See text for details.