Building an ecosystems-type fisheries management approach for the Campecheh Bank, subarea in the Gulf of Mexico Large Marine Ecosystem

摘要

In this contribution, we discuss the need for an ecosystems-type fisheries management approach, especially when the Campeche Bank subarea of the Gulf of Mexico Large Marine Ecosystem (LME) is strongly influenced by environmental changes. In these circumstances, the carrying capacity and the subarea structure and its organization do not reflect the stability assumed for conventional stock assessment approaches. The subarea re-organizes in response to environmental change, and sustainable fishing and management must be adapted. This necessity is particularly relevant under the effects of climate change since those changes have a defined tendency. We also show evidence of a clear signal of climate change effects on the Campeche Bank subarea of the Gulf of Mexico LME and how changes in fish stocks can be misinterpreted under conventional stock assessment methods. Moreover, evidence is shown regarding how the subarea has evolved during the last six decades, giving a clear example of re-organization. Management schemes are discussed briefly; addressing why they fail and suggesting an approach to identify a limiting subarea reference level termed noxicline, which represents the limit of the loss of biomass of the components of a subarea after which the domain deteriorates. The noxicline also permits identification of the corresponding harvest rate limit at the stock level. As an average the harvest rate to be applied in the Campeche Bank subarea should be no larger than 40%. This approach can be useful under the effects of climate change, since harvest rates reflect the proportion of the stock that is extracted, regardless of its size.