Abstract

At a global level, there is evidence of a decrease in the biomass of most fish species, due to the fishing pressure exert through years, which in an ecological scale has generated changes in the marine trophic webs, especially the decrease of mean trophic level, situation called “Fishing down marine food webs”. Avoiding the geographic over-aggregation and with data from evaluation cruisers, an analysis of the historic trends (from 1964 to 2001) of the mean trophic level, of the piscivore/omnivore fish ratio and of the elasmobranch/teleost ratio, is made for the Colombian Caribbean Sea continental shelf. A clear decline in demersal fish mean trophic level has been identified. Moreover, the importance of estimating the trophic level with the local data is test, by comparing between them and the recorded in the Fishbase data base. Due to that the fishes show wide distribution and that every system have a unique trophic structure that depends of its own life history. With the results obtain here, information about changes in the structure and function of the ecosystem will be achieve, with the purpose to supply points of reference for the restoration of marine resource.

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