The structure of Marine Ecosystems: An Alternative

Abstract

In "The Structure of Marine Ecosystems" (1974), Steele developed a simulation model which suggested that the stability of planktonic communities was dependent on a threshold response allowing phytoplankton a refuge in concentration below which herbivorous zooplankton did not feed. Observations from the North Sea were present- ed to support this hypothesis. In order to more realistically represent the simu- lated herbivores, Calanus spp., several of Steele's assumptions have been modified. The results of the revised model indicate that feeding thresholds are not essen- tial for the long-term realism and stability of the simulated system and suggest an alternative, ecosystem control through predation.