Photoacclimation is the process by which plants and phytoplankton adjust the concentration and composition of their photosynthetic machinery (i.e. their photoacclimation state) in response to changes in their light or nutrient environment. The purpose of photoacclimation is to balance the rate at which light energy is absorbed with the energetic...
In situ optical measurements of spectral absorption and beam attenuation provide information on the fine scale horizontal and vertical variations in phytoplankton pigments and other measures of phytoplankton photophysiology and ecology in coastal waters. Phytoplankton pigment ratios from discrete sample analyses with High Performance Liquid Chromatography were compared to in...
The influence of nitrate availability and irradiance on phytoplankton natural fluorescence was investigated in laboratory cultures of the marine diatom Thalassiosira weissflogii (Bacillariophyceae). Two cultures of phytoplankton, differing only in the nitrate-limited growth rate, were compared to learn how increases in irradiance influences natural fluorescence. Instrumentation was developed for these...
Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites may be released into the surrounding seawater and could inhibit primary production. On the other hand, some phytoplankton can use...
Physical-biological interactions in the Southern Ocean were investigated using remote sensing data from several different satellite sensors. Satellite sea surface temperature data were used to study the dynamics of the Antarctic Polar Front (PF). Satellite ocean color data were used to estimate surface chlorophyll concentrations and their relation to various...
The Oregon upwelling system is a region of high biomass and primary
productivity as well as strong mesoscale variability. In order to examine the
interaction of physical forcing and ecosystem dynamics, four 3-week sampling
cruises were conducted in the Oregon upwelling system as part of the Northeast
Pacific Global Ocean...
The suspension-feeding mud shrimp, Upogebia pugettensis, is a common inhabitant of intertidal mudflats in estuaries throughout the Pacific Northwest, where it develops extensive burrows. Also inhabiting the shrimps' burrow is the commensal bivalve, Cryptomya californica. Filtration by dense populations of the shrimp and its commensals may have a negative impact...
Few studies have examined the partitioning of organic matter in upwelling systems,
despite the fact that these systems play a key role in carbon and nitrogen budgets in the
ocean. We examined the production and partitioning of phytoplankton-derived organic
matter in deck incubations off Oregon during the upwelling season. During...
