Evaluation of quantitative indicators for marine fish communities

In the development of ecosystem-based fisheries management, the assessment of ecosystem status is a key element. There are many indicators that can be used to assess the status of an ecosystem that are representative of key ecosystem processes and properties. Yet, of the several hundred indicators available to evaluate marine ecosystems, which are the best to use? We evaluated multiple biotic indicators from the Northeast U.S. large marine ecosystem (LME) to determine their potential utility in assessing ecosystem status, with a particular emphasis on the fish community and fishing pressure. For those 26 indicators which met our selection criteria, we executed a multivariate ordination to evaluate how indicators group together rank in terms of explanatory power, and are weighted relative to one another. The ordination procedure also revealed indicator redundancies. We recommend a set of eight candidate indicators for routine monitoring that are both representative of major processes and sensitive to fishing-related ecosystem changes. Finally, we briefly explore the role these indicators might have in ecosystem-based fishery management.