Abstract


USING ECOSYSTEM PROPERTIES TO DETECT TRANSITIONAL STATES IN CORAL REEF FISH ASSEMBLAGES

Ecosystem-based fisheries management requires the means to detect ecosystem change. Indicators based on single species, food webs, or subsets of the full community (e.g. biomass in a particular trophic group) have utility, but may not be sensitive to cumulative effects, or to variation in system level processes. System level indicators, such as those that relate to the distribution of energy across trophic levels, provide a means to identify whether a system is moving into or out of a state of disturbance or recovery. These cumulative biomass indicators have recently been shown to be robust and reliable for discerning ecosystem perturbation in > 100 different marine ecosystems. Therefore, integrative trophic level information appears to be a suitable entire-system indicator of global application. There is, however, uncertainty over how and to what extent these indicators are affected when there are large inputs of allochthonous nutrients, as is common in systems such as estuaries and coral reefs, thus limiting the utility of this approach to those systems. Here, we test the effect of allochthonous material on the accumulation of biomass across trophic levels in coral reef fish assemblages. We find strong differences in the basal biomass and trophic level inflection point (the point where maximum biomass is observed) in relation to background oceanic productivity, temperature and fishing pressure. By accounting for these natural environmental drivers, we can improve upon the utility of this system level metric as an indicator of human-induced perturbation for coral reefs.

Authors

Heenan, A., JIMAR - NOAA Pacific Islands Fisheries Science Center, USA, adel.heenan@gmail.com

Gove, J., NOAA Pacific Islands Fisheries Science Center, USA, jamison.gove@noaa.gov

Link, J., NOAA Northeast Fisheries Science Center, USA, jason.link@noaa.gov

Polovina, J., NOAA Pacific Islands Fisheries Science Center, USA, jeffrey.polovina@noaa.gov

Pranovi, F., University Ca’ Foscari, Italy, fpranovi@unive.it

Weijerman, M., JIMAR - NOAA Pacific Islands Fisheries Science Center, USA, mariska.weijerman@noaa.gov

Williams, I., NOAA Pacific Islands Fisheries Science Center, USA, ivor.williams@noaa.gov

Details

Oral presentation

Session #:17
Date: 06/23/2016
Time: 13:45
Location: 313 A

Presentation is given by student: No