Dataset: respiration-excretion rates - micronekton
Deployment: LMG0203

Mean respiration and excretion rates for micronekton

Principal Investigator:

Dr Joseph J. Torres (University of South Florida, USF)

BCO-DMO Data Manager:

Ms Dicky Allison (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

U.S. GLOBEC Southern Ocean (SOGLOBEC)

Deployment Synonyms:

GLOBECIII

Coordinated Deployments:

NBP0202

Data URL:

https://www.bco-dmo.org/dataset-deployment/450510/data

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Description

Mean respiration and excretion rates for micronekton Southern Ocean GLOBEC

Collection of specimens. Crustaceans were collected using either mouth-closing Tucker trawls (9.0 m² or 2.25 m² mouth area) or downward-looking, vertically deployed plummet nets (1 m² mouth area). Tucker trawls were equipped with either blind or thermal-turbulence-protecting cod-ends (Childress et al. 1978); plummet nets terminated in bind cod-ends only. Specimens were taken in the upper 1000m of the water column in the vicinity of the marginal ice zone during spring (November-December) 1983, fall (March) 1986, and winter (June-August) 1988 as part of the AMERIEZ (Antarctic Marine Ecosystem Research at the Ice Edge Zone) program to study ice edge biology. Sampling locations were all in the Scotia-Weddell Sea region but moved with seasonal movement of the pack ice edge. Thus, spring and winter collections were in the Scotia Sea in the vicinity of 60deg S, 40deg W; fall sampling took place further south, 65deg S, 46deg W. Collections were made on a continuum from deep in the pack ice out to 300 km seaward of the ice edge in fall and winter. In spring, collections were made in the open water only. Station locations are given in Donnelly et al. (1990).

Oxygen consumption rates were determined by allowing individuals to deplete the oxygen in a sealed container filled with filtered (0.45 um pore size) seawater. Temperature was maintained at 0.5 C (+/- 0.1 C) using a refrigerated water bath. Oxygen partial pressure (PO₂) was continuously monitored using a Clark polarographic oxygen electrode (Clark 1956) as an individual reduced oxygen levels to low (10 to 20 mm Hg) partial pressures. Electrodes were calibrated using air- and nitrogen-saturated seawater at the experimental temperature. The time required for consumption of oxygen to low levels varied from 12 to 18 h. Streptomycin and Neomycin (each 25 mg 1^-1) were added to the seawater to minimize microbial growth. To control for possible oxygen consumption by microorganishs, an individual was removed after selected runs, its volume was replaced with fresh seawater, and oxygen consumption was again measured for 2 to 4 h. In all cases microbial oxygen consumption was negligibly low.

References:
Torres, Joseph J., et al., 2007; The physiology of autumn and winter krill (Euphausia superba) in the waters of the Western Antarctic Peninsula Shelf. GLOBEC International Newsletter, 13:1, 60-62.

Contact:
Jose Torres
College of Marine Science
University of South Florida
140 Seventh Avenue, South
St. Petersburg, FL 33701
jtorres@marine.usf.edu

Methods & Sampling

Dataset acquisition description

Sampling was conducted with two nets.

Deployment-specific acquisition description

Collection of specimens. Crustaceans were collected using either mouth-closing Tucker trawls (9.0 m² or 2.25 m² mouth area) or downward-looking, vertically deployed plummet nets (1 m² mouth area). Tucker trawls were equipped with either blind or thermal-turbulence-protecting cod-ends (Childress etal. 1978); plummet nets terminated in bind cod-ends only. Specimens were taken in the upper 1000m of the water column in the vicinity of the marginal ice zone during spring (November-December) 1983, fall (March) 1986, and winter (June-August) 1988 as part of the AMERIEZ (Antarctic Marine Ecosystem Research at the Ice Edge Zone) program to study ice edge biology. Sampling locations were all in the Scotia-Weddell Sea region but moved with seasonal movement of the pack ice edge. Thus, spring and winter collections were in the Scotia Sea in the vicinity of 60ï¿½ S, 40ï¿½ W; fall sampling took place further south, 65ï¿½ S, 46ï¿½ W. Collections were made on a continuum from deep in the pack ice out to 300 km seaward of the ice edge in fall and winter. In spring, collections were made in the open water only. Station locations are given in Donnelly etal (1990).

Data Processing Description

Dataset Processing Description

Deployment-specific processing description

Oxygen consumption rates were determined by allowing individuals to deplete the oxygen in a sealed container filled with filtered (0.45 um pore size) seawater. Temperature was maintained at 0.5degC (+/- 0.1degC) using a refrigerated water bath. Oxygen partial pressure (PO<sub>2</sub>) was continuously monitored using a Clark polarographic oxygen electrode (Clark 1956) as an individual reduced oxygen levels to low (10 to 20 mm Hg) partial pressures. Electrodes were calibrated using air- and nitrogen-saturated seawater at the experimental temperature. The time required for consumption of oxygen to low levels varied from 12 to 18 h. Streptomycin and Neomycin (each 25 mg 1<sup>-1</sup>) were added to the seawater to minimize microbial growth. To control for possible oxygen consumption by microorganishs, an individual was removed after selected runs, its volume was replaced with fresh seawater, and oxygen consumption was again measured for 2 to 4 h. In all cases microbial oxygen consumption was negligibly low.

More information about this dataset deployment

Funding

Award Number	Funding Source
ANT-9910100	NSF Antarctic Sciences

Instruments

Tucker Trawl

Supplied Description:

Tucker trawls (9.0 m² or 2.25 m ² mouth area) were equipped with either blind or thermal-turbulence-protecting cod-nets (Childress etal. 1978)

Instrument Type

Generic Name: Tucker Trawl

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0161/

Generic Description:

The original Tucker Trawl, a net with a rectangular mouth opening first built in 1951 by G.H. Tucker, was not an opening/closing system, but shortly thereafter it was modified so that it could be opened and closed. The original had a 183 cm by 183 cm flexible rectangular mouth opening 914 cm long net with 1.8 cm stretched mesh for the first 457 cm and 1.3 cm mesh for last 457 cm. 152 cm of coarse plankton or muslin netting lined the end of the net. Tucker designed the net to collect animals associated with the deep scattering layers, principally euphausiids, siphonophores, and midwater fish. (from Wiebe and Benfield, 2003). Currently used Tucker Trawls usually have 1-m2 openings and can have a single net or multiple nets on the frame.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
species	Species name.	text	species
season	Season of the year (fall or winter).	text	season
number	Number of individuals in the calculation of the mean, four cruises represented.	integer	number
size_class	Size of the animal.	unitless	no_bcodmo_term
WetMass	Mean wet mass of individuals in milligrams, four cruises represented.	mg	no_bcodmo_term
WetMass_stdev	Standard deviation of WetMass.	mg	no_bcodmo_term
H2O	Mean percent water in animals, four cruises represented.	percent	no_bcodmo_term
H2O_stdev	Standard deviation of H2O.	percent	no_bcodmo_term
Ash	Mean percent Ash in animal, four cruises represented.	percent	no_bcodmo_term
Ash_stdev	Standard deviation of Ash.	percent	no_bcodmo_term
O2_consumed	Mean O2 consumed per individual per hour, four cruises represented.	uL O2 per individual per hour	no_bcodmo_term
O2_consumed_stdev	Standard deviation of O2_consumed.	uL O2 per individual per hour	no_bcodmo_term
VO2	Mean oxygen consumed per mg wet weight per hour, four cruises represented.	uL O2 per mg wet weight per hr	no_bcodmo_term
VO2_stdev	Standard deviation of VO2.	uL O2 per mg wet weight per hr	no_bcodmo_term
N_excrete	Mean of micrograms nitrogen excreted per individual per hour, four cruises represented.	ug per individual per hour	no_bcodmo_term
N_excrete_stdev	Standard deviation of N_excrete.	ug per individual per hour	no_bcodmo_term
N_excrete_mass	Mean of micrograms nitrogen excreted per milligram of wet mass per hour, four cruises represented.	ug N per mg wet mass per hour	no_bcodmo_term
N_excrete_mass_stdev	Standard deviation of N_excrete_mass.	ug N per mg wet mass per hour	no_bcodmo_term
OtoN	mean oxygen to nitrogen ratio, four cruises represented	unitless	no_bcodmo_term
OtoN_stdev	Standard deviation of OtoN.	unitless	no_bcodmo_term

Database

Contribute Data

Dataset: respiration-excretion rates - micronekton
Deployment: LMG0203

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Database

Contribute Data

Dataset: respiration-excretion rates - micronektonDeployment: LMG0203

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Dataset: respiration-excretion rates - micronekton
Deployment: LMG0203