Detecting trajectories of change in marine ecosystems: Biotic indicators for observing systems

Federal, regional, state, territorial, tribal, and local aquatic resource review processes have all moved towards implementation of Ecosystem-Based Management (EBM). This provides an opportunity to improve ocean, coastal, and Great Lakes stewardship versus continuing with a fragmented, sector-specific process that only looks at individual components of or influences on an ecosystem. To accomplish this goal, EBM requires integrated ecosystem assessments. These assessments require observing data that reflect the pressures and responses that are of concern to managers. Monitoring and indicators of the physical aspects of marine systems are well developed, as is the development and application of models for the physical features of marine ecosystems. Although extant and monitored, relative to physical features, indicators of marine habitat and the biota need to be better integrated with Ocean Observing Systems. This will ensure sufficient monitoring to detect critical changes in marine ecosystems. Here we review a suite of such ecosystem indicators to measure change in the biological properties of marine ecosystems. From that, we provide recommendations for their integration within the US Integrated Ocean Observing System (U.S IOOS).