Physical, optical, and acoustical data from Monterey Bay, California, USA, describing the distributions of phytoplankton, zooplankton, and small fish as well as gradients in the physical habitat were used to examine the interactions between vertically compressed plankton structures (thin layers), their consumers, and the local physical forces they experience. The relationship between upper and lower edge gradients of a layer w...

Temporal changes in phytoplankton pigments and spectral absorption were evaluated during June 1998 in East Sound, Orcas Island, Washington. High‐resolution vertical profiles of in situ spectral absorption were obtained with a Wet Labs ac‐9 (nine‐wavelength absorption and beam attenuation meter), and pigment concentrations were determined for discrete water samples using high‐performance liquid chromatography (HPLC). Fucoxanthi...

Surveys of the California Current System in 1993 revealed high concentrations of photosynthetic pigment biomass at ∼200‐m depth, well below the euphotic zone. The deep fluorescence feature contained an estimated 2.2 × 10 4 metric tons of carbon and contained ∼2.5 times the amount of chlorophyll observed in surface waters directly above it. Deep phytoplankton assemblages may be a signature of water mass subduction, suggesting t...