Sampling data, experimental data and fecal pellet characteristics of water pump samples in the strait of Øresund between Denmark and Sweden during 2004/2005

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Main Authors: Poulsen, Louise K, Iversen, Morten Hvitfeldt
Format: Dataset Open Access
Language:en
Published: PANGAEA 2010
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author Poulsen, Louise K
Iversen, Morten Hvitfeldt
author_facet Poulsen, Louise K
Iversen, Morten Hvitfeldt
collection Datos científicos de ciencias marinas y ambientales
contents Copepod fecal pellets are often degraded at high rates within the upper part of the water column. However, the identity of the degraders and the processes governing the degradation remain unresolved. To identify the pellet degraders we collected water from Øresund (Denmark) approximately every second month from July 2004 to July 2005. These water samples were divided into 5 fractions (<0.2, <2, <20, <100, <200 µm) and total (unfractionated). We determined fecal pellet degradation rate and species composition of the plankton from triplicate incubations of each fraction and a known, added amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Øresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 ± 0.49 d**–1) and minimum (0.52 ± 0.14 d**–1) during late winter. Total pellet removal rate ranged from 22% d**–1 (July 2005) to 87% d**–1 (May). Protozooplankton (dinoflagellates and ciliates) in the size range of 20 to 100 µm were the key degraders of the fecal pellets, contributing from 15 to 53% of the total degradation rate. Free-living in situ bacteria did not affect pellet degradation rate significantly; however, culture-originating bacteria introduced in association with the pellets contributed up to 59% of the total degradation rate. An effect of late-stage copepod nauplii (>200 µm) was indicated, but this was not a dominating degradation process. Mesozooplankton did not contribute significantly to the degradation. However, grazing of mesozooplankton on the pellet degraders impacts pellet degradation rate indirectly. In conclusion, protozooplankton seems to include the key organisms for the recycling of copepod fecal pellets in the water column, both through the microbial loop and, especially, by functioning as an effective 'protozoan filter' for fecal pellets.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_730359
institution PANGAEA
language en
publishDate 2010
publisher PANGAEA
record_format pangaea
spellingShingle Sampling data, experimental data and fecal pellet characteristics of water pump samples in the strait of Øresund between Denmark and Sweden during 2004/2005
Poulsen, Louise K
Iversen, Morten Hvitfeldt
Center for Marine Environmental Sciences; CTD, Seabird; CTD-R; MARUM; Strait of Øresund; Øresund_2004-2005
Copepod fecal pellets are often degraded at high rates within the upper part of the water column. However, the identity of the degraders and the processes governing the degradation remain unresolved. To identify the pellet degraders we collected water from Øresund (Denmark) approximately every second month from July 2004 to July 2005. These water samples were divided into 5 fractions (<0.2, <2, <20, <100, <200 µm) and total (unfractionated). We determined fecal pellet degradation rate and species composition of the plankton from triplicate incubations of each fraction and a known, added amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Øresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 ± 0.49 d**–1) and minimum (0.52 ± 0.14 d**–1) during late winter. Total pellet removal rate ranged from 22% d**–1 (July 2005) to 87% d**–1 (May). Protozooplankton (dinoflagellates and ciliates) in the size range of 20 to 100 µm were the key degraders of the fecal pellets, contributing from 15 to 53% of the total degradation rate. Free-living in situ bacteria did not affect pellet degradation rate significantly; however, culture-originating bacteria introduced in association with the pellets contributed up to 59% of the total degradation rate. An effect of late-stage copepod nauplii (>200 µm) was indicated, but this was not a dominating degradation process. Mesozooplankton did not contribute significantly to the degradation. However, grazing of mesozooplankton on the pellet degraders impacts pellet degradation rate indirectly. In conclusion, protozooplankton seems to include the key organisms for the recycling of copepod fecal pellets in the water column, both through the microbial loop and, especially, by functioning as an effective 'protozoan filter' for fecal pellets.
title Sampling data, experimental data and fecal pellet characteristics of water pump samples in the strait of Øresund between Denmark and Sweden during 2004/2005
topic Center for Marine Environmental Sciences; CTD, Seabird; CTD-R; MARUM; Strait of Øresund; Øresund_2004-2005
url https://doi.org/10.1594/PANGAEA.730359