The mean trophic level of Uruguayan landings during the period1990-2001

摘要

The worldwide increasing trend in fishing catches together with the impact of fishing on ecosystems and inefficient fishery management have led to overfishing and frequent collapse of traditional fish stocks. In this context, the assessment of fishery-induced impacts and the implementation of ecosystem-based fisheries management programs are urgently required. In this study, the mean trophic level (TLm) and the fishing-in-balance (FIB)-index of Uruguayan landings during 1990 and 2001 were estimated using the trophic level of 60 fishery resources. A decline in total landings (Y) is observed, which is explained by the lower fishing yield in major fishery resources (especially demersal). Moreover, a marked decreasing trend in TLm at a rate of approximately 0.28 trophic levels per decade, and a decreasing trend in FIB-index since 1997 were observed. The present situation of fishery resources in Uruguay (fully exploited or overexploited) and the drop in Y, FIB and TLm can be considered as indirect indicators of the fishing impacts on the trophic structure of Uruguayan marine communities. We suggest that a more holistic ecosystem-based fisheries management could help to alleviate the critical situation of fish stocks in Uruguayan waters.