Patterns of genetic population structure in commercially exploited Brazilian marine fishes

Over 60% of all fish stocks are overexploited, requiring urgent and effective conservation and management planning. Designing management strategies requires knowing the geographic limits of stocks (populations). Populations... [ view full abstract ]

Over 60% of all fish stocks are overexploited, requiring urgent and effective conservation and management planning. Designing management strategies requires knowing the geographic limits of stocks (populations). Populations can represent units with independent demographic, adaptive and genetic characteristics, and these factors can affect their response to exploitation. Currently there are no genetic data describing population structure for multiple, co-distributed marine fish species in Brazil. Here, we aim to determine major patterns of genetic population structuring of commercial marine fishes for the entire Brazilian coast. We are using Arlequin software to analyse mitochondrial (COI, CytB) and nuclear (Rhodopsin) DNA sequences to identify population structure of 60 economically important species. We expect to find different patterns among species that relate to their habits and reproductive type: species with pelagic juveniles and adults will probably show no structure along the coast, while species with pelagic juveniles and sedentary adults are likely to be structured according to environmental variables, as sea surface temperature, oceanic currents, and barriers (e.g. mouth of big rivers). Identifying general patterns is crucial for sustainable practice, especially for countries like Brazil, and most developing countries, where most fishery operators do not target individual species.