Dataset: VPR_ashjian_orig
Deployment: EN259

Video Plankton Recorder data

Principal Investigator:

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

BCO-DMO Data Manager:

Ms Dicky Allison (Woods Hole Oceanographic Institution, WHOI)

Project:

U.S. GLOBEC Georges Bank (GB)

Current State:

Final no updates expected

Version Date:

2012-07-25

Data URL:

https://www.bco-dmo.org/dataset-deployment/449546/data

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Description

This dataset includes ALL the abundance values, zero and non-zero. The data files are very large. In order to map the VPR data, see the VPR_ashjian_nonzero [http://globec.whoi.edu/jg/serv/globec/gb/vpr_cashjian_nonzero.html0]. In the 'nonzero' dataset, values of 0 in the abund_L column (taxon abundance) have been removed.

For an alternate display, including both zero and non-zero data, see VPR_ashjian_alt [http://globec.whoi.edu/jg/serv/globec/gb/vpr_cashjian_read.html0].

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

Dataset acquisition description

Deployment-specific acquisition description

Data Processing Description

Dataset 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.

Deployment-specific processing description

<p>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.</p>

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

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

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^3	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
brief_desc	Brief description of the type of cruise.	dimensionless	brief_desc
Hydroids	asexual hydroid phase of Cnidarians	number/liter; close to presence or absence	abundance
Other	other zooplankton not categorized	number/liter; close to presence or absence	abundance
Cerianthid	Cerianthids	number/liter; close to presence or absence	abundance
Calanus	Calanus sp. but likely finmarchicus	number/liter; close to presence or absence	abundance
Earlyphaeoproto	Early phaeocystis spp. Protocolonies	number/liter; close to presence or absence	abundance
Phaeoproto	Phaeocystis spp. protocolonies	number/liter; close to presence or absence	abundance
Marinesnow	Particles of plankton marine snow	number/liter; close to presence or absence	abundance
Pteropod	Pteropods	number/liter; close to presence or absence	abundance
Chaetognath	Chaetognaths	number/liter; close to presence or absence	abundance
Pseudocalanus	Pseudocalanus spp.	number/liter; close to presence or absence	abundance
Cope_uid	unidentified copepods	number/liter; close to presence or absence	abundance
Pseudowegg	Pseudocalanus with eggs	number/liter; close to presence or absence	abundance
Amphipods	Amphipods	number/liter; close to presence or absence	abundance
Euphausiid	Euphausiids	number/liter; close to presence or absence	abundance
Hydromedusa	Hydromedusae	number/liter; close to presence or absence	abundance
Medusa_uid	unidentified medusae	number/liter; close to presence or absence	abundance
Algalmat	Collections of diatom chains	number/liter; close to presence or absence	abundance
Larvacean	Larvaceans	number/liter; close to presence or absence	abundance
Echinoderm	Echinoderm	number/liter; close to presence or absence	abundance
Dino_Ceratium	Dinoflagellate Ceratium species	number/liter; close to presence or absence	abundance
Diat_Csocialis	Diatom Chaetoceros socialis	number/liter; close to presence or absence	abundance
Diat_Chaetoceros	Diatom Chaetoceros	number/liter; close to presence or absence	abundance
Diatomchain	Diatom chains	number/liter; close to presence or absence	abundance
Cyclopoid_uid	unidentified Cyclopoids	number/liter; close to presence or absence	abundance
Ctenophore	Ctenophores	number/liter; close to presence or absence	abundance
Polychaete	Polychaetes	number/liter; close to presence or absence	abundance
Unidentified	Unidentified objects	number/liter; close to presence or absence	abundance
Centropages	Centropages species	number/liter; close to presence or absence	abundance
Oithona	Oithona species	number/liter; close to presence or absence	abundance
Phytoplankton	Phytoplankton taxa	number/liter; close to presence or absence	abundance

Database

Contribute Data

Dataset: VPR_ashjian_orig
Deployment: EN259

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Database

Contribute Data

Dataset: VPR_ashjian_origDeployment: EN259

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Dataset: VPR_ashjian_orig
Deployment: EN259