Marine & Environmental Sciences Faculty Articles

Multisensor Sampling of Pelagic Ecosystem Variables in a Coastal Environment to Estimate Zooplankton Grazing Impact

Document Type

Article

Publication Date

1-2001

Publication Title

Continental Shelf Research

Keywords

Zooplankton, Phytoplankton, Grazing, Red tides, Plankton sampling, USA, Florida, West Florida shelf

ISSN

0278-4343

Volume

21

Issue/No.

1

First Page

69

Last Page

87

Abstract

Sampling was conducted on the west Florida continental shelf ecosystem modeling site to estimate zooplankton grazing impact on primary production. Samples were collected with the high-resolution sampler, a towed array bearing electronic and optical sensors operating in tandem with a paired net/bottle verification system. A close biological–physical coupling was observed, with three main plankton communities: 1. a high-density inshore community dominated by larvaceans coincident with a salinity gradient; 2. a low-density offshore community dominated by small calanoid copepods coincident with the warm mixed layer; and 3. a high-density offshore community dominated by small poecilostomatoid and cyclopoid copepods and ostracods coincident with cooler, sub-pycnocline oceanic water. Both high-density communities were associated with relatively turbid water. Applying available grazing rates from the literature to our abundance data, grazing pressure mirrored the above bio-physical pattern, with the offshore sub-pycnocline community contributing ∼65% of grazing pressure despite representing only 19% of the total volume of the transect. This suggests that grazing pressure is highly localized, emphasizing the importance of high-resolution sampling to better understand plankton dynamics. A comparison of our grazing rate estimates with primary production estimates suggests that mesozooplankton do not control the fate of phytoplankton over much of the area studied (<5% grazing of daily primary production), but “hot spots” (∼25–50% grazing) do occur which may have an effect on floral composition.

Comments

©2001 Elsevier Science Ltd. All rights reserved.

Additional Comments

Office of Naval Research grant #s: ONR-N00014-96-1-5020, ONR-N00014-97-1-0504

ORCID ID

0000-0002-5280-7071

DOI

doi:10.1016/S0278-4343(00)00074-1

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Peer Reviewed

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