In situ grazing rates of deep-sea benthic boundary-layer zooplankton

Document Type

Article

Date of Original Version

12-1-1984

Abstract

In situ grazing rates of mixed assemblages of deep-sea benthic boundary-layer zooplankton were measured in July 1983 at a site in the North Atlantic Ocean at 2 175 m depth using a short-term radioisotope-uptake method. Zooplankton were collected with an opening-closing net system from the bottom 1 m of the ocean and incubated in situ with mixed tritiated amino acids in special cod-end chambers. Incubations were terminated at depth by the addition of MS-222. Radioisotope uptake beyond that of dead controls was shown by both the zooplankton and particulate fractions. Grazing rates in the deep-sea experiments were surprisingly high, being comparable to wintertime Narragansett Bay zooplankton grazing rates determined in a separate series of laboratory experiments. These laboratory experiments also documented nonparticle-associated uptake of dissolved amino acids by Narragansett Bay zooplankton, but the importance of this in the deep sea is unknown. The deep-sea benthic boundary layer may be a region of elevated rates and activity because of its higher particulate concentrations, and our experiments may also have measured maximum rather than average rates. © 1994 Springer-Verlag.

Publication Title, e.g., Journal

Marine Biology

Volume

84

Issue

1

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