The Northern Humboldt Current Ecosystem and its resource dynamics: Insights from a trophic modeling and time series analysis

The Northern Humboldt Current Ecosystem (NHCE) is one of the most productive in the world. Wind-driven coastal upwelling brings cool, nutrient-rich water to the photic zone where rich plankton communities develop. This high productivity supports large populations of small plankton-grazing pelagic fish, which are an important food source for many higher predators and support a large fish meal industry. The NHCE is subject to strong interannual environmental variability from the El Nino Southern Oscillation (ENSO), which has direct and indirect effects on the biotic components of the ecosystem. This complex mixture of environmental, trophic, and human influences calls for a holistic approach for management. This thesis contributes to our understanding of the NHCE by shedding light on the changes in energy flow that occur during strong El Nino events (warm phase of ENSO) as well as differentiating between the relative importance of environmental, trophic, and human influences in reproducing historical changes in fisheries resources. Methods included the application of time-series and trophic modeling analyses for two NHCE subsystems of different scale: i) the nearshore benthic ecosystems of Independencia Bay and Sechura Bay (2 models, include the area of