Joint effects of top-down and bottom-up forces on the structure and dynamics of estuarine and coastal marine communities: Interactions between nutrient inputs and fisheries exploitation

• Fiorenza Micheli

Abstract

I propose to conduct a review and synthesis of existing information on the joint effects of bottom-up and top-down forces on the ecosystem dynamics of estuarine and coastal marine communities. The objective of this synthesis is to produce conceptual models and generalizations on how anthropogenic nutrient loading and alterations of food-web structure caused by fisheries exploitation interact to influence the structure, function, and dynamics of these communities. I propose to conduct cross-system comparisons of the interactive effects of nutrient loading and food-web structure on primary productivity, plant biomass, and fisheries production in estuarine and coastal marine communities. In addition, I propose to investigate temporal trends of these variables by focusing on a few systems where long-term data are available at State fisheries agencies.

This synthesis will improve aquatic ecosystem management in the face of two major anthropogenic disturbances that are jointly applied to aquatic systems nearly universally, nutrient inputs and fisheries exploitation.