Amplification of environmental fluctuations by marine ecosystems

Environmental variability is an important cause of fluctuations in marine ecosystems. Some ecosystems appear to have characteristic resonant frequencies, and even a weak environmental signal at one of these frequencies can cause large changes in population sizes. It is already known that some commercial fish stocks undergo abundance cycles which can be explained in this way, since models of their population dynamics exhibit resonances at or near the appropriate frequencies. In this paper it is shown that resonance found in Lotka-Volterra models of predator-prey systems appears to be a likely cause of many of the fluctuations found in marine ecosystems