The comparative ecology of six marine ecosystems

Comparison of six marine ecosystems uses a network analysis of carbon flows for the Swartkops and Ems estuaries, Chesapeake Bay, the Baltic Sea and the Peruvian and Benguela upwelling regions. There is an inverse correlation between the Finn Cycling Index (FCI) and the normalized internal ascendancy or system maturity (Ai:Ci). There is also a clear distinction between Ai:Ci and the production:biomass (P:B) ratio; in upwelling systems the P:B and Ai:Ci ratios are both high, whereas in estuarine systems the P:B ratio is low. The P:B ratio thus cannot be used as an indicator of marine ecosystem evolution. Contrary to current views on ecosystems, the aggregate amount of cycling of materials, such as carbon, is not an indication of system maturity but rather of stress. The reason that higher stressed systems are associated with a higher throughput or FCI could be because perturbations frequently impact higher-level species to a greater extent than the lower trophic components. Any release of standing biomass from these higher levels could therefore be taken up through increased recycling via short intense loops. -from Authors