Dataset: MOCNESS - Zooplankton

Name: MOCNESS tow zooplankton abundance estimates from R/V New Horizon cruise NH1008 in Monterey Bay, near MBARI buoy M1 (36.747?N, 122.022?W); 2010 (GATEKEEPERS project)
Published: 2014-11-24
Keywords: oceans

Cite This Dataset

Spatial Extent: N:37.049883 E:-122.017367 S:36.432483 W:-123.458783

Project:

Zooplankton feeding at the base of the particle maximum: Gatekeepers of the Vertical Flux? (GATEKEEPERS)

Principal Investigator:

David M. Checkley (University of California-San Diego Scripps, UCSD-SIO)

Co-Principal Investigator:

Michael Dagg (Louisiana Universities Marine Consortium, LUMCON)

George A. Jackson (Texas A&M University, TAMU)

Contact:

David M. Checkley (University of California-San Diego Scripps, UCSD-SIO)

BCO-DMO Data Manager:

Stephen R. Gegg (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

24 November 2014

Version Date:

2014-11-24

Restricted:

Current State:

Preliminary and in progress

MOCNESS tow zooplankton abundance estimates from R/V New Horizon cruise NH1008 in Monterey Bay, near MBARI buoy M1 (36.747?N, 122.022?W); 2010 (GATEKEEPERS project)

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Description

The abundance (# m^-3, ppm) for selected taxa in each analyzed MOCNESS deployment averaged over upcast nets.

Related reference:
Dagg, M.J., G.A. Jackson, and D.M. Checkley, Jr. (in press). The distribution and vertical flux of fecal pellets from large zooplankton in Monterey Bay and coastal California." Deep-Sea Research Part I.

Methods & Sampling

Sample Collection: Samples were collected using a 1-m² MOCNESS net with 202-micron-mesh nets, pressure sensor and flowmeter. Tow speed was generally 0.5-1 m sec^-1. Only those samples from selected net openings were analyzed and only data from those analyses are provided. In general, for each MOCNESS deployment, samples from 3-5 nets opened and closed sequentially from the lowest depth (zl, m) to the shallowest, or upper, depth (zu, m) were analyzed. We present here the abundances for selected taxa enumerated in each deployment averaged over all upcast samples.

Data Processing Description

Sample Analysis: Samples were split multiple times using a Folsom splitter. Specific taxa were identified and enumerated in one or more splits using a dissecting microscope. Equivalent spherical diameter (ESD) was estimated from length and width and assuming a geometric shape for individual taxa. For discretely sized taxa (Calanus pacificus adult females, adult males, and fifth copepodites: C.pac AF, AM, C5; Metridia pacifica adult females: M.pac AF; Euclanus californicus adult males, adult females, and fourth and fifth copepodites: E.cal AF, AM, C4,C5) mean ESD was calculated from all nets together. For other taxa (other large cops, euphausiids, and small zooplankton), mean ESD was calculated for each net where present and the means were weighted to estimate the mean ESD for all nets. Mean volume was calculated from mean ESD for each taxon using the equation ⅙π (mean ESD)³. Abundance of each taxon was calculated by multiplying counts in each net by their corresponding split factors, summing over all nets and dividing by the sum volume filtered for all nets. Mean volume was multiplied by abundance for each taxon to calculate volume in cm³m^-3 or ppm. Number of individuals measured and counted in each taxonomic group was retained to display where low counts produce uncertainty in calculations.

BCO-DMO Processing Notes
- Generated from original file: "NH1008_MN_integrated_zoop_16sept13_jfb_no_header.xlsx" contributed by David Checkley
- Parameter names edited to conform to BCO-DMO naming convention found at Choosing Parameter Name
- "MOCNESS_" pre-pended to Tow Id for consistency with MOCNESS stations tow ids
- Date/Time and Lat/Lon deployed added to each record from MOCNESS stations to enable use in MapServer

Data Files

File
MOCNESS_Zoop.csv (Comma Separated Values (.csv), 11.42 KB) MD5:af3967e693224aaf87cb4b6f94c396f8 Primary data file for dataset ID 540832

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-0927863
NSF Division of Ocean Sciences	OCE-0928139
NSF Division of Ocean Sciences	OCE-0928425

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
NH1008	GATEKEEPERS	2010-07-08	R/V New Horizon	David M. Checkley (Chief Scientist)	data info

Instruments

Folsom Plankton Splitter

Supplied Name: Folsom Splitter

Supplied Description:

Samples were split multiple times using a Folsom splitter.

Instrument Type

Generic Name: Folsom Plankton Splitter

Acronym: Folsom Splitter

Generic Description:

A Folsom Plankton Splitter is used for sub-sampling of plankton and ichthyoplankton samples.

MOCNESS

Supplied Description:

Samples were collected using a 1-m2 MOCNESS net with 202-micron-mesh nets, pressure sensor and flowmeter. Tow speed was generally 0.5-1 m sec-1. Only those samples from selected net openings were analyzed and only data from those analyses are provided. In general, for each MOCNESS deployment, samples from 3-5 nets opened and closed sequentially from the lowest depth (zl, m) to the shallowest, or upper, depth (zu, m) were analyzed

Instrument Type

Generic Name: MOCNESS

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. There are currently 8 different sizes of MOCNESS in existence which are designed for capture of different size ranges of zooplankton and micro-nekton Each system is designated according to the size of the net mouth opening and in two cases, the number of nets it carries. The original MOCNESS (Wiebe et al, 1976) was a redesigned and improved version of a system described by Frost and McCrone (1974).(from MOCNESS manual) This designation is used when the specific type of MOCNESS (number and size of nets) was not specified by the contributing investigator.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Taxon	Taxon enumerated in respective net tow	text	taxon
MN_Tow	Sequential number of MN deployment	Dimensionless	tow
Date_Deployed	Deployment Date (PDT)	YYYYMMDD	date_start
Time_Deployed	Deployment Time (PDT)	HHMM	time_start
Latitude_Deployed	Deployment Latitude (South is negative)	decimal degrees	lat_start
Longitude_Deployed	Deployment Longitude (West is negative)	decimal degrees	lon_start
zl	Estimated deepest depth of tow	meters	depth_max
zu	Upper depth (in this case the surface)	meters	depth_min
Abund	Numerical abundance averaged over depth of tow	individuals m-3	abundance
Vol	Volumetric abundance averaged over depth of tow	ppm	abundance
Number_Measured	Number of individuals measured to estimate mean Equivalent spherical diameter (ESD)	individuals	count
Number_Counted	Number of individuals counted to estimate abundance	individuals	count

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Database

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Dataset: MOCNESS - Zooplankton