Microbial size spectra from diverse marine ecosystems
Citable URI
https://hdl.handle.net/1912/5664Location
Massachusetts BayCape Cod Bay
Sargasso Sea
Equatorial Pacific
DOI
10.1575/1912/5664Abstract
Characteristics of microbial size spectra (bacteria and phytoplankton) were examined in
relation to changes in ecosystem productivity and environmental perturbations. Samples
were obtained from productive coastal waters in Massachusetts and Cape Cod Bays,
oligotrophic waters in the Sargasso Sea and high nutrient, low chlorophyll waters in the
equatorial Pacific. In general, a relative predominance of larger bacteria and
phytoplankton cells was observed in early spring, where low temperatures resulted in wellmixed
waters and high nutrient concentrations. Seasonal succession was accompanied by
a shift in the size spectrum to smaller cells, coinciding with rising temperatures,
stratification of the water column and diminishing nutrient concentrations. In stratified
waters, larger mean bacteria and phytoplankton sizes were observed in surface and deep
waters, whereas smaller sizes were observed around the chlorophyll maximum. Bacteria
and phytoplankton growth were well correlated with mean bacteria sizes varying
positively with mean phytoplankton sizes. Data pooled from all locations showed that the
size spectral characteristics most sensitive to environmental change were the mean cell
size, bacteria intercept and phytoplankton slope of the normalized concentration size
spectrum. Increases in ecosystem productivity, chlorophyll, particulates and nutrients
were generally accompanied by shifts in the size spectra to larger bacteria and
phytoplankton.
Description
Submitted in partial fulfillment of the requirements for the degree of Doctor of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1996
Suggested Citation
Thesis: Gin, Karina Y. H., "Microbial size spectra from diverse marine ecosystems", 1996-06, DOI:10.1575/1912/5664, https://hdl.handle.net/1912/5664Related items
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