What is ecosystem data?
Factors other than fishing can have an important role in determining the health and abundance of fish stocks. Ecosystem factors such as complex interactions among species in the marine food web, changes in marine coastal habitat, and constantly changing ocean environmental factors may be important. Examples of ecosystem data that may inform stock assessments include:
- Time series of physical or environmental data (i.e. ocean temperature, currents, etc.) that help scientists understand fluctuations in fish stocks and improve calibration of surveys that monitor stocks
- Information on the effects of large-scale climate processes (e.g. El Niño) and climate change (Read more about the Fisheries and the Environment program...)
- Information on species habitat utilization, the quantity and quality of marine habitats, and the impacts of fishing on habitat (Read more about the Habitat Science program...)
- Predator-prey and other studies that provide more accurate values for important stock assessment parameters such as natural mortality
Traditionally, fish stock assessments have relied on direct measurements of fish stocks and catch to determine abundance and potential catch levels for individual stocks one at a time. This approach is effective for looking at present and historical conditions of single species, but limited when trying to understand why changes occurred because it only accounts for the effects of fishing. This approach can also be limited when making forecasts of sustainable catch levels because it does not account for ecosystem factors that may impact fish abundance.
Evolving information needs associated with ecosystem-based fisheries management enables new and innovative approaches to stock assessment. Integrated analysis models have the capability to include environmental and ecosystem factors. For example, time series of environmental factors such as ocean temperature and currents help scientists to better understand historical fish stock changes and improve forecasts. Other ecosystem studies can provide more accurate values for important stock assessment parameters such as natural mortality.
Before ecosystem factors can effectively be incorporated into more stock assessments, additional research is needed. Research needs include:
- Determining the most important ecosystem factors that cause changes in fish populations
- Continued development of advanced assessment models capable of including ecosystem data
- Collecting ecosystem data in ongoing monitoring programs