LAUSR

Abstract Human communities living around Cartagena Bay (Colombian Caribbean) depend on fishing activities as their main income and food source. This resource has been affected by pollution, sedimentation and overfishing. DNA barcoding was used for fish species identification, and the genetic diversity and population structure of two valued fish genera, snappers (Lutjanus spp.) and jacks (Caranx spp.) from the main fishing grounds in the area was evaluated. Fishermen collected tissue samples and measured size and weight and capture location for each fish. A 700 base pairs (bp) fragment of the mitochondrial Cytochrome Oxidase I (COI) was sequenced for 104 samples (55 snappers and 49 jacks). Comparisons against Genbank allowed identification of eight species: Lutjanus synagris, L. apodus, L. jocu, L. cyanopterus, L. analis, Caranx hippos, C. latus and C. crysos. Genetic diversity for the fish around the Colombian Caribbean sampling locations was relatively high in comparison to those of other populations and population differentiation was significant for some species, particularly for L. synagris and L. apodus, suggesting that the fish from the Colombian Caribbean belong to an independent stock. Mean body length for all species was significantly smaller than body length at maturity, indicating that all fish captured were immature. Levels of genetic diversity appear to be high in these fish populations. The fact that fishermen are capturing immature fish is worrisome, suggesting the need to improve management of fish populations and the need to include the communities in conservation planning for the Islas del Rosario National Natural Park.