Currin, C. A. NOAA, Carolyn.Currin@noaa.gov
Pinckney, J. L. Texas A&M University, Dept. of Oceanography, Pinckney@ocean.tamu.edu
BENTHIC MICROALGAL MEDIATION OF SURFICIAL SEDIMENT GEOCHEMISTRY
Benthic microalgae are ubiquitous in shallow-water benthic environments which receive at least 1% of incident irradiation. Despite their often nondescript appearance, and typically restricted to the top 1mm or less of sediment, benthic microalgae exert a large influence on overall sediment geochemistry and benthic-pelagic coupling. Benthic microalgae respond to physical and chemical changes at the sediment-water interface with spatial (vertical migration) and temporal (photosynthesis, respiration, N uptake/fixation) changes in their activity. Together, these result in dissolved inorganic carbon (DIC) and oxygen (O2) gradients which can change over extremely short temporal and spatial scales. These variable gradients in DIC and O2 exert controls on sediment pH, redox, and nutrient flux, and must be incorporated into models which describe fluxes and benthic-pelagic coupling of nutrients and primary production. Rapid changes in sediment DIC concentration also confound utilization of radioactive C (C14) uptake to
measure primary production and grazing rates of benthic microalgae.
Day: Thursday, Feb. 4
Time: 10:30 - 10:45am
Location: Hilton of Santa Fe