Summer Microzooplankton in the Bering Sea

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Metadata:

Identification_Information
Data_Quality_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Diane K. Stoecker
Originator: Kristen L. Blattner
Publication_Date: Unpublished material
Title: Summer Microzooplankton in the Bering Sea
Geospatial_Data_Presentation_Form: spreadsheet

Description:

Abstract:: MZ grazing on phytoplankton was estimated during the summer cruise (HLY0803) at 21 stations in the SE Bering Sea. Experiments were conducted with water collected from the mixed layer at the depth corresponding to ~50% surface irradiance and then prescreened through a 200 μm mesh. A modified 2-point dilution method (Landry 1993, Strom et al. 2006, Strom & Fredrickson 2008) was used to estimate phytoplankton growth (μ, d-1), MZ grazing (g, d-1) and the fraction of phytoplankton daily production removed by microzooplankton grazing (g/μ). Parallel incubations were run without and with the addition of nutrients to alleviate nutrient limitation in the diluted treatments. Incubations were done on-deck under simulated in situ conditions for ~ 24 h. Chlorophyll (total and <20 μm) was measured as a proxy for phytoplankton biomass. Water samples for the determination of MZ abundance, biomass and composition were collected in association with the dilution experiments and at additional selected stations and preserved with 10% (final concentration) acid Lugol’s solution in amber glass bottles. MZ samples were returned to Horn Point Laboratory for enumeration of > 20 μm MZ (> ~15 μm when fixed with acid Lugol’s) using settling slides and a Nikon Eclipse TE 2000-U inverted microscope. A SPOT v 4.0 RT camera and SPOT diagnostic software were used to record images and to measure cells. In accordance with earlier MZ studies in the Bering Sea, ciliates smaller than 20 μm and mixotrophic dinoflagellates as well heterotrophic dinoflagellates were enumerated.
Purpose:: This project addresses the BSIERP hypothesis that “Climate-induced changes in physical forcing will modify the availability and partitioning of food for all trophic levels through bottom-up processes”. MZ are responsible for most of the grazing on phytoplankton in the sea and are an important link in the food chain between phytoplankton and zooplankton, which are food for zooplanktivorous fish which support top predators. The project contributes to the goals of BSIERP by providing summer data on standing stocks of MZ and their grazing activities. A key goal is to determine how the MZ link in Bering Sea food webs is influenced by climate-induced changes in physical forcing.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20080703
Ending_Date: 20090710

Currentness_Reference: observed

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Description_of_Geographic_Extent: Southeast Bering Sea

Bounding_Coordinates:

West_Bounding_Coordinate: -179.3883
East_Bounding_Coordinate: -163.1383
North_Bounding_Coordinate: 62.2040
South_Bounding_Coordinate: 54.3086

Keywords:

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword:: microzooplankton, phytoplankton, grazing, growth, biomass, composition, abundance

Theme:

Theme_Keyword_Thesaurus: IOOS Core Variables
Theme_Keyword: Version 1
Theme_Keyword: Biology
Theme_Keyword: Ocean Color

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: project_number:B55
Theme_Keyword: data_url:<http://data.eol.ucar.edu/codiac/dss/id=245.B55-002>
Theme_Keyword: archive_url:<http://www.eol.ucar.edu/projects/bsierp>

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Bering Sea, Arctic

Taxonomy:

Keywords/Taxon:

Taxonomic_Keyword_Thesaurus: None
Taxonomic_Keywords: dinoflagellate
Taxonomic_Keywords: myrionecta rubra
Taxonomic_Keywords: oligotrich
Taxonomic_Keywords: choreotrich
Taxonomic_Keywords: tintinnid
Taxonomic_Keywords: ciliate
Taxonomic_Keywords: silicoflagellate

Taxonomic_System:

Classification_System/Authority:

Classification_System_Citation:

Citation_Information:

Originator:

ADL S.M., A.G.B Simpson, M.A. Farmer, R.A. Andersen, O.R. Anderson, J.R. Barta, S.S. Bowser, G. Brugerolle et al.

Publication_Date: 2005

Title:

The New Higher Level Classification of Eukaryotes with Emphasis on the Taxonomy of Protists

Geospatial_Data_Presentation_Form: journal article

Series_Information:

Series_Name: J. Eukaryot. Microbiol.
Issue_Identification: 52(5)

Other_Citation_Details: pp. 399-451

Classification_System/Authority:

Classification_System_Citation:

Citation_Information:

Originator: Krainer, K.H. and W Foissner

Publication_Date: 1990

Title:

Revision of the genus Askenasia Blochmann, 1895 with proposal of two new species and description of Rhabdoaskenasia minima n.g., n. sp. (Ciliophora, Cyclotrichida)

Geospatial_Data_Presentation_Form: journal article

Series_Information:

Series_Name: J. Protozool
Issue_Identification: 37

Other_Citation_Details: pp. 414-427

Taxonomic_Procedures:

Water samples were obtained using 30 l Niskin bottles. Duplicate samples (250 ml) for MZ were preserved with 10% (final concentration) acid Lugol’s solution in amber glass bottles. MZ samples were returned to Horn Point Laboratory for enumeration of > 20 μm MZ (> ~15 μm when fixed with acid Lugol’s) using settling slides and a Nikon Eclipse TE 2000-U inverted microscope. In our data sheets an “0” indicates <40 cells/liter. A SPOT v 4.0 RT camera and SPOT diagnostic software were used to record images and to measure cells. In accordance with earlier MZ studies in the Bering Sea, ciliates smaller than 20 μm and mixotrophic dinoflagellates as well as heterotrophic dinoflagellates were enumerated. Onboard, we examined “fresh” samples, either live or fixed with 1% glutaraldehyde with transmitted light and epifluorescence microscopy to look for the presence or absence of plastids. Our notes from the cruise facilitated in determination of which ciliates and dinoflagellates were photosynthetic (had chlorophyll fluorescence) and which were strictly heterotrophic (no chlorophyll fluorescence except associated with algae in food vacuoles). Separate data sheets are presented for ciliates, dinoflagellates and “other” microzooplankton.
The ciliate abundance and biomass data are presented in 5 categories. MR= Myionecta rubra (=Mesodinium rubrum). This is a photoautotrophic ciliate which consumes cryptophytes and other small prey. MO=Mixotrophic oligotrichs; these ciliates graze on phytoplankton (usually nanophytoplankton) but have chlorophyll and are also photosynthetic. Only ciliates which we observed to have chlorophyll at sea and which we could recognize as the same species in the Lugol’s fixed samples are included in this category on the data sheets. Thus, it is a minimum estimate of mixotrophic ciliates. OC=Oligotrich and naked choreotrich ciliates (mostly heterotrophs). This category may include a few MO that we were not able to recognize in the Lugol’s samples. The ciliates in the OC category are mostly grazers. TI=Tintinnid ciliates. Other=All other ciliates.
The dinoflagellate abundance and biomass data are presented in 4 categories. PD=plastidic dinoflagellates; these dinoflagellates had chlorophyll and were probably mixotrophic since most photosynthetic dinoflagellates can also graze. THD=thecate heterotrophic dinoflagellates. NTHD=non-thecate heterotrophic dinoflagellates. UNK=Dinoflagellates which we were not able to classify as plastidic or non-plastidic in the Lugol’s fixed samples based on our notes from onboard observations.
The MZ “Other” data includes microzooplankton not identified as ciliates or dinoflagellates. It includes 2 categories. SF=silicoflagellates, OtherHP= other heterotrophic protists.

General_Taxonomic_Coverage:

Dinoflagellates= Dinophyceae (Pasher 1914 in Adl et al. 2005 p. 433)
Oligotrichs= Oligotrichia (Butschll 1887, in Adl et al. 2005 p. 436)
Choreotrichs= Choreotrichia (Small and Lynn 1985, in Adl et al. 2005 p. 436)
Tintinnids= Choreotrichs with a lorica (Adl et al. 2005)
Ciliates= Ciliophora (Doflein 1901 in Adl et al. 2005 p.435)
Silicoflagellates= Dictyochales (Haeckel 1894, in Adl et al. 2005 p.427)
Myrionecta rubra (Lohman 1908, in Jankowski 1976, see Krainer and Foissner 1990)