Abstract
Anthropogenic activities such as large-scale fisheries affect the genetic profiles of socioeconomically important species. The degree to which fish genetic resources are depleted is unknown, however, and intraspecific genetic variation is largely neglected in fisheries management. Basic knowledge of the spatial and temporal genetic variability patterns of commercially important species is largely missing in spite of the fact that such information is needed for sustainable management. This research address the effects of fisheries on gene pool retention using cod and herring as model organisms. Based on observed genotypic patterns and computer modelling we will assess the amount of temporal genetic change in these species in Swedish waters over a 30-year period, estimate their effective population sizes (Ne), and model the effects on Ne from various harvesting regimes. Genotypic information on present day spatial structure is already available, and will be compared with material collected over 30 years ago in the same regions. We will address the following questions: i) have recent management practices affected the genetic structures of herring and cod in Swedish waters? ii) what are the effective population sizes of these species? iii) how is Ne affected by different strategies for harvesting? iv) what genetic aspects are most important for promoting sustainable management of these fish resources?
Sweden