Microscale distributions of phytoplankton: initial results from a two-dimensional imaging fluorometer, OSST

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 220:59-72 (2001) - doi:10.3354/meps220059 Microscale distributions of phytoplankton: initial results from a two-dimensional imaging fluorometer, OSST Peter J. S. Franks*, Jules S. Jaffe Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0218, USA *E-mail: pfranks@ucsd.edu ABSTRACT: A digital camera system was designed to photograph laser-stimulated fluorescence of phytoplankton in situ at 0.67 x 0.67 cm resolution over an area of 70 x 70 cm. In a series of vertical profiles, 1200 images were collected. Criteria were developed to reject images smeared by camera motions (due to ship heave), and images taken when vertical velocities were >0.2 m s-1, leaving 240 good images. Horizontal velocities calculated using ancillary data from the FishTV imaging sonar showed the water to be directed toward the imaging plane during the deployment, supporting the hypothesis that images were uncontaminated by mixing from the instrument package. Images passing all the criteria show strong isotropic spatial variability. The averaged spatial spectrum was flat, suggesting an underlying random distribution of brightly fluorescent particles‹probably phytoplankton aggregates. Such observations have important implications for our understanding of the food environment of herbivorous zooplankton, and the mechanisms creating and maintaining patchiness in the ocean. KEY WORDS: Microscale · Patchiness · Fluorescence · Phytoplankton · Fluorometer Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 220. Online publication date: September 27, 2001 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2001 Inter-Research.