Trophic Structure

Northeast management objective

Maintain trophic structure within acceptable limits

Management objectives related to trophic structure include the maintenance and monitoring of ecosystem trophic structure, which refers to the relative biomass of feeding guilds within the system. Trophic structure is tied to ecosystem productivity and resilience and can be affected by many interrelated factors such as climate variability, changes to lower trophic level community composition and biomass, and changes in fish condition and recruitment. The Northeast Fisheries Science Center (NEFSC) monitors ecosystem trophic structure from whales to phytoplankton through a variety of methods, including remote sensing of ocean productivity, surveys of lower trophic level community structure and species abundance, biannual survey trawls, and visual surveys of protected species. Recent work has shown that the trophic structure in the Northeast Large Marine Ecosystem (NE-LME) is driven in part by cyclical "regime" dynamics, which are related to fishing pressures, large-scale environmental drivers, and ecological dynamics. Robust trophic structure in marine communities is vital to ecosystem health and productivity, making this an important target for responsible management practices.

See data that indicates the status and trends of this management objective such as zooplankton abundance, groundfish condition, and Atlantic cod abundance here.

Simplified food web tracing primary productivity through the ecosystem (Credit: Kimberly Hyde/NOAA)
Food web tracing primary productivity through a generalized marine ecosystem
(Credit: Kimberly Hyde/NOAA)