On the stabilizing role of stage structure in piscene consumer-resource interactions

A stage-structured consumer-resource model is investigated using plausible biological parameter estimates. The model, developed from patterns in energy allocation across fish life-history strategies, explicitly considers the effects of delays in maturation on juvenile growth and mortality. It is found that stage structure in the consumer fish population tends to locally stabilize consumer-resource dynamics for realistic parameters. Additionally, it is shown that stage structure bounds nonequilibrium behavior relative to the case without stage structure. Finally, it is shown that the increased stability and bounding of solutions has the seemingly paradoxical consequence of promoting nonequilibrium dynamics when even small amounts of noise are added to the system. (C) 1998 Academic Press.