Benthic Community Production 
Under Upwelling Zones

Jim Barry, Kurt Buck
(MBARI)

Coupling between primary production in the surface waters and the biomass and productivity of benthic communities have been described in general for various ocean regions. The strength of pelagic-benthic coupling in regions of upwelling is expected to be high, however, it may vary greatly both spatially and temporally. Near Monterey Bay, the availability of organic carbon for the benthos may depend upon the location and depth in relation to upwelling plumes, the interannual and seasonal variability, as well as the relative contributions of phytoplankton-derived material and other inputs (e.g., macrophytic debris).

In cooperation with concurrent water-column studies in upwelling areas, we will measure both the input and character of organic debris to the seafloor and the resulting benthic productivity beneath these upwelling areas. Our activities included the deployment of :

  • Benthic landers equipped with instruments to estimate organic input (in-situ fluorometers, transmissometers, sediment traps, current meters);

  • In-situ respirometers to measure benthic community carbon uptake;

  • AUVs with video or photographic capabilities to document the structure and distribution of megafaunal communities;

  • ROVs to deploy and recover sediment samples for various analyses (e.g., carbon and pigments).

Landers also contained samplers from 03 meters above the bottom to document the conditions in the benthic boundary layers.

These initial studies served as a prototype system including commercially available sensors (e.g., in situ fluorometers). Future deployments may depend on new sensors that can measure directly dissolved organic carbon and particulate organic carbon. In addition, new water samplers and time-series sediment samplers may provide samples for more detailed measurements of the character of organic inputs.

A prototype lander, which could be ready to deploy in the summer of 2000 to augment the planned water-column studies, would contain core instruments such as current meters, fluorometers, and transmissometers. Sediment trap studies may require collaboration with other scientists within MBARI or from other institutions. 

Data Index Aircraft AUV CODAR
Drifters Moorings Satellites Ships