Dataset: VPR_ashjian_alt

Name: Video Plankton Recorder data (formatted with taxa displayed in single column); from R/V Columbus Iselin and R/V Endeavor cruises CI9407, EN259, EN262 in the Gulf of Maine and Georges Bank from 1994-1995
Published: 2012-07-31
Keywords: oceans

Cite This Dataset

Spatial Extent: N:42.38351 E:-66.286005 S:40.9115 W:-67.541526

Project:

U.S. GLOBEC Georges Bank (GB)

Program:

U.S. GLOBal ocean ECosystems dynamics (U.S. GLOBEC)

Principal Investigator:

Carin J. Ashjian (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

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

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

2012-07-31

Version Date:

2012-07-31

Restricted:

Validated:

Current State:

Preliminary and in progress

Video Plankton Recorder data (formatted with taxa displayed in single column); from R/V Columbus Iselin and R/V Endeavor cruises CI9407, EN259, EN262 in the Gulf of Maine and Georges Bank from 1994-1995

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Description

This dataset includes ALL the abundance values, zero and non-zero. Taxonomic groups are diplayed in the 'taxon' column, rather than in separate columns, with abundances in the 'abund_L' column. For the original presentation of the data, see VPR_ashjian_orig. For a version of the data with only non-zero data, see VPR_ashjian_nonzero. In the 'nonzero' dataset, values of 0 in the abund_L column (taxon abundance) have been removed.

Methodology
The following information was extracted from C.J. Ashjian et al., Deep- Sea Research II 48(2001) 245-282 . An in-depth discussion of the data and sampling methods can be found there.

The Video Plankton Recorder was towed at 2 m/s, collecting data from the surface to the bottom (towyo). The VPR was equipped with 2-4 cameras, temperature and conductivity probes, fluorometer and transmissometer. Environmental data was collected at 0.25 Hz (CI9407) or 0.5 Hz (EN259, EN262). Video images were recorded at 60 fields per second (fps).

Video tapes were analyzed for plankton abundances using a semi-automated method discussed in Davis, C.S. et al., Deep-Sea Research II 43 (1996) 1946-1970. In-focus images were extracted from the video tapes and identified by hand to particle type, taxon, or species. Plankton and particle observations were merged with environmental and navigational data by binning the observations for each category into the time intervals at which the environmental data were collected (again see above Davis citation). Concentrations were calculated utilizing the total volume (liters) imaged during that period. For less-abundant categories, usually only a single organism was observed during each time interval so that the resulting concentrations are close to presence or absence data rather than covering a range of values.

Methods & Sampling

Data Processing Description

Video tapes were analyzed for plankton abundances using a semi-automated method discussed in Davis, C.S. et al., Deep-Sea Research II 43 (1996) 1946-1970. In-focus images were extracted from the video tapes and identified by hand to particle type, taxon, or species. Plankton and particle observations were merged with environmental and navigational data by binning the observations for each category into the time intervals at which the environmental data were collected (again see above Davis citation). Concentrations were calculated utilizing the total volume (liters) imaged during that period. For less-abundant categories, usually only a single organism was observed during each time interval so that the resulting concentrations are close to presence or absence data rather than covering a range of values.

BCO-DMO re-formatted the data by converting taxonomic columns to rows. The original data display can be seen in the VPR_ashjian_orig dataset.

Data Files

File
vpr_cashjian_read.csv (Comma Separated Values (.csv), 370.26 MB) MD5:e84f43da333c04bd20c60cead70a9f7e Primary data file for dataset ID 3685

More Information about this dataset

Funding Sources

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

Deployments

Deployment	Start Date	Platform	Investigator
CI9407	1994-05-25	R/V Columbus Iselin	Dian J. Gifford (Chief Scientist)	data info
EN259	1995-01-10	R/V Endeavor	Dr Edward Durbin (Chief Scientist)	data info
EN262	1995-02-23	R/V Endeavor	Cabell S. Davis (Chief Scientist)	data info

Instruments

Video Plankton Recorder

Supplied Description:

Video Plankton Recorder, a towed vehicle.
The Video Plankton Recorder was towed at 2 m/s, collecting data from the surface to the bottom (towyo). The VPR was equipped with 2-4 cameras, temperature and conductivity probes, fluorometer and transmissometer. Environmental data was collected at 0.25 Hz (CI9407) or 0.5 Hz (EN259, EN262). Video images were recorded at 60 fields per second (fps).

Instrument Type

Generic Name: Video Plankton Recorder

Acronym: VPR

Generic Description:

The Video Plankton Recorder (VPR) is a video-microscope system used for imaging plankton and other particulate matter in the size range from a few micrometers to several centimeters. The VPR is essentially an underwater microscope. It consists of four video cameras (with magnifying optics) synchronized at 60 fields per second (fps) to a red-filtered 80 W xenon strobe (pulse duration = 1 microsecond). The current lens on each camera can be adjusted to provide a field of view between 5 mm and 10 cm. Use of higher magnification lenses is currently being explored for viewing protozoans (less than 1 micrometer resolution). The four cameras are set for concentric viewing fields so that a range of up to four magnifications can be viewed simultaneously, allowing a wide size range of plankton to be sampled. Depth of field is adjusted by the lens aperture setting, and the volume sampled in each video field ranges from about 1 ml to 1 liter, depending on lens settings. The cameras have been configured for stereoscopic viewing as well.A strobe on the other arm illuminates the imaged volume and flashes 60 times per second, producing 60 images per second of the particles and plankton in the water. The images are then saved internally on a computer hard disk and later plotted.

Deployment: Most commonly, the VPR is mounted in a frame and lowered into the water from the stern of the ship. Sometimes, a CTD also is mounted next to the VPR to collect depth, temperature, and salinity information at the same time as each video image. The instrument is lowered down through the water to a maximum depth of 350 meters to generate a profile of plankton/particle abundance and taxon group along with temperature and salinity. In addition to the towed configuration for mapping plankton distributions, it is possible to deploy the VPR in a fixed position (on a mooring) for viewing plankton swimming behaviors in two or three dimensions. The VPR instrument system has been used in both configurations, and deployment on ROVs has been proposed.

This definition was taken from the WHOI Ocean Instruments Web site and from a US GLOBEC Newsletter.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
cruiseid	Cruise identification		cruiseid
year	year GMT		year
yrday0_gmt	year day, Jan 1 = 0, GMT	YYY.Y	yrday0_gmt
month_gmt	month, GMT		month_gmt
day_gmt	day of tow, GMT		day_gmt
time_gmt	hour and decimal minute of binned video image, GMT	HHmm.m	time_gmt
lat	latitude, negative = south	decimal degrees	lat
lon	longitude, negative = west	decimal degrees	lon
press	pressure, depth of data interval	decibars	press
temp	temperature	degrees centigrade	temp
sal	salinity, derived using Neil Brown software	PSU	sal
sigma_t	sigma_t, density	kilograms/meter<sup>3</sup>	sigma_t
flvolt	fluorescence	volts	flvolt
fluor	fluorescence	relative units	fluor
trans_v	light transmission	volts	trans_v
dist_along_track	distance along ship's track	kilometers	no_bcodmo_term
taxon	Name of the taxonomic group. Hydroids = asexual hydroid phase of Cnidarians Other = other zooplankton not categorized Calanus = Calanus sp. but likely finmarchicus Phaeoproto = Phaeocystis spp. protocolonies Marinesnow = Particles of plankton Pseudocalanus = Pseudocalanus spp. Cope_uid = unidentified copepods Pseudow egg = Pseudocalanus with eggs Medusa_uid = unidentified medusa Algalmat = Collections of diatom chains Dino_Ceratium = Ceratium spp. Diat_Csocialis = Chaetoceros socialis Diat_Chaetoceros = Chaetoceros spp. Cyclopoid_uid = unidentified cyclopoid Unidentified = unidentified objects Centropages = Centropages spp. Oithona = Oithona spp.	dimensionless	taxon
abund_L	Taxon abundance (number per Liter). Note: 1 cubic meter = 1,000 L.	number/Liter	abundance
brief_desc	Brief description of the type of cruise.	dimensionless	brief_desc

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Dataset: VPR_ashjian_alt