Linking Terrestrial Processes, Coastal Landscapes, and Marine Ecosystems

Driven by the necessity to predict future fishery yields the environmental mechanisms that determine the magnitude of ecosystem-level production have received a great deal of attention; in particular within the coastal zone, where an estimated 70% of commercial fish are captured. However, given the decrease of coastal catch and commercial fisheries expanding into the high seas, our relatively scarce knowledge of oceanic stocks and the issue of oceanic resources management are increasingly coming to international attention.

Here I extend the use of statistical models to the high seas to test if the patterns observed in the coastal realm hold fast. Furthermore, as fisheries are driven by more than environmental factors, here the role of the ‘human dimension’ is investigated, through the integration of human-derived nutrient run-off, fishing effort and market value. A key finding is a shift in the significance of environmental versus anthropogenic variables between the coastal zone and the high seas, indicating the need for differential management strategies. Moreover, I found that within the coastal region the observed yield of Large Marine Ecosystems (LMEs) is driven by different environmental and anthropogenic variables according to the target fishery and ecosystem characteristics of the LME, suggesting statistical models aggregated to a global scale mask spatail variability in the drivers of fisheries yield.

This work reinforces the evidence that there is no ‘silver bullet’ in the management of fisheries, and that management needs to take into account both the intrinsic variability of the underlying ecosystem and economic drivers (e.g. market price, development of fishing gears, new technologies etc.) when predicting and managing fish stocks.