Dataset: zoo_MOC_GoM
Deployment: EN307

Zooplankton (including Calanus finmarchicus stages) abundance and biomass from MOCNESS tows, Gulf of Maine

Principal Investigator:

Peter H. Wiebe (Woods Hole Oceanographic Institution, WHOI)

Technician:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI)

Project:

U.S. GLOBEC Georges Bank (GB)

Data URL:

https://osprey.bco-dmo.org/dataset-deployment/452984/data

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Description

The primary objective of the project was to quantify the distribution of the diapausing copepod Calanus finmarchicus and its primary invertebrate predators in Wilkinson, Jordan, and Georges basins of the Gulf of Maine.

Methods & Sampling

Dataset acquisition description

Zooplankton samples were collected in October (1997-1999) and December (1998-1999) using a 1-meter² MOCNESS tow with 9 nets and 335 micron mesh towed obliquely with the first net open on the down-haul and the other 8 nets sequentially opened on the up-haul. Only the contents of the up-haul nets are reported here, including the temperature and salinity measurements

Data Processing Description

Dataset Processing Description

Samples were split and photographed using the silhouette photographic method (Davis, 1985) and then the organisms were identified to taxonomic group and their length measured using Matlab based software described by Little & Copley (2003). Biomass for the taxa were calculated using formulae established by Wiebe et al (1975) and Wiebe (1988). Calanus biomass was calculated for each stage and net sample by multiplying the average length of the animals in the sample for that stage by the average wet weight for the same group. One Calanus' average wet wgt = 0.086*{avg. len}^2.809.

Small spheres tend to be copepod eggs, large spheres are usually fish eggs, and egg sacs are typically from the copepod Paraeuchaeta norvegica.

References:

Davis, C. S. and Wiebe, P. H. (1985) Macrozooplankton biomass in a warm-core Gulf Stream ring: time series changes in size structure, taxonomic composition, and vertical distribution. J. Geophys. Res., 90, 8871-8884.

Little, W. S. and Copley, N. J. (2003) WHOI Silhouette DIGITIZER version1.0 User's Guide. In: Woods Hole Oceanogr. Inst. WHOI-2003-05: 66 pp.

Wiebe, P. H., Boyd, S. and Cox, J. L. (1975) Relationship between zooplankton displacement volume, wet weight, dry weight and carbon. Fish. Bull., 73, 777-786.

Wiebe, P. H., Burt, K. H., Boyd, S. H., et al. (1976) A multiple opening/closing net and environmental sensing system for sampling zooplankton. Journal of Marine Research, 34, 313-326.

Wiebe, P. H. (1988) Functional regression equations for zooplankton displacement volume, wet weight, dry weight, and carbon: A correction. Fishery Bulletin, 86, 833-835.

BCO-DMO data manager processing notes:
* Version 2 (2021-05-18) replaces version 1 (2009-12-23). There was an unsupported character in the source file now fixed after the encoding conversion to utf-8.

More information about this dataset deployment

Funding

Award Number	Funding Source
unknown GB NOAA	National Oceanic and Atmospheric Administration
unknown GB NSF	National Science Foundation

Instruments

MOCNESS1

Supplied Description:

1 m^2 MOCNESS with 335 micron mesh, 9 nets.

Instrument Type

Generic Name: MOCNESS1

Acronym: MOC1

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/

Generic Description:

The Multiple Opening/Closing Net and Environmental Sensing System or MOCNESS is a family of net systems based on the Tucker Trawl principle. The MOCNESS-1 carries nine 1-m2 nets usually of 335 micrometer mesh and is intended for use with the macrozooplankton. All nets are black to reduce contrast with the background. A motor/toggle release assembly is mounted on the top portion of the frame and stainless steel cables with swaged fittings are used to attach the net bar to the toggle release. A stepping motor in a pressure compensated case filled with oil turns the escapement crankshaft of the toggle release which sequentially releases the nets to an open then closed position on command from the surface. -- from the MOCNESS Operations Manual (1999 + 2003).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruiseid	cruise identifier, e.g. EN307 R/V Endeavor cruise 307		cruiseid
cast	tow number		cast
site	Basin where sample was collected		site
year	year, reported as YYYY, e.g. 2010		year
month_local	month of year, local time		month_local
day_local	day, local time		day_local
time_local	time of day, local time, using 2400 clock format		time_local
day_night	whether the tow occured in the day, night, dawn, dusk		no_bcodmo_term
net	net number		net
depth_mid	depth at the midpoint of the opened net, used with MOCNESS tows	meters	depth_mid
depth_interval	thickness of water layer sampled	meters	depth_interval
temp_avg	average temperature of the water for a single net	degrees Celsius	temp
sal_avg	average salinity of the water passing through the net		sal
taxon3	taxonomic description		taxon
abund	number of the specific taxa/group counted per meter3	number/meter^3	abundance
biomass	wet weight of a specific taxa/group identified, in units milligrams per meter3	mg/m^3	wet_weight_biomass
comments	comment pertaining to sample		comment
lat	latitude, in decimal degrees, North is positive, negative denotes South	decimal degrees	lat
lon	longitude, in decimal degrees, East is positive, negative denotes West	decimal degrees	lon
yrday_local	local day and decimal time, as 326.5 for the 326th day of the year, or November 22 at 1200 hours (noon)		yrday_local
taxon1	subphylum, class, order or family		taxon
taxon2	subphylum, class, order or family		taxon
kingdom	taxonomic kingdom		taxon
phylum	phylum (animal) or division (plants)		taxon
stage	organism life history stage	unitless	stage

Database

Contribute Data

Dataset: zoo_MOC_GoM
Deployment: EN307

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: zoo_MOC_GoMDeployment: EN307

Dataset acquisition description

Dataset Processing Description

Dataset: zoo_MOC_GoM
Deployment: EN307