Biomass data from an Optical Plankton Counter (OPC) collected on R/V New Horizon, R/V Thomas G. Thompson, and R/V Roger Revelle cruises NH0005, NH0007, T0205, and R0208 in the Northeast Pacific from 2000-2002 (NEP project)

Website: https://www.bco-dmo.org/dataset/3744
Version: 1
Version Date: 2012-10-16

Project
» U.S. GLOBEC Northeast Pacific (NEP)

Program
» U.S. GLOBal ocean ECosystems dynamics (U.S. GLOBEC)
ContributorsAffiliationRole
Zhou, MengUniversity of Massachusetts Boston (UMB-SMS)Principal Investigator
Allison, DickyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager
Rauch, ShannonWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

This dataset includes ALL the biomass values, zero and non-zero. OPC size classes are diplayed in the 'size_class' column, rather than in separate columns, with biomass for each class in the 'biomass' column. For the original presentation of the data, see opc_ccs_orig. For a version of the data with only non-zero data, see opc_ccs_nonzero. In the 'nonzero' dataset, values of 0 in the biomass column have been removed. 

U.S. GLOBEC Northeast Pacific California Current Program
Optical Plankton Counter (OPC) Data


Contact for this dataset is:
Meng Zhou
Dept. of Environmental, Coastal and Ocean Sciences
University of Massachusetts-Boston
Boston, MA 02125
Email: meng.zhou@umb.edu
Phone: 617-287-7419; Lab: 617-287-6186
FAX: 617-287-7474

This project addresses one of 3 central hypotheses of the U.S. GLOBEC Northeast Pacific (NEP) Study:

Spatial and temporal variability in mesoscale circulation constitutes the dominant physical forcing on zooplankton biomass, production, distribution, species interactions and retention and loss in coastal regions.(U.S. GLOBEC Northeast Pacific Implementation Plan, U.S. GLOBEC Report No. 17).

References:
Rodriguez, J. and M. M. Mullin. 1986. Relation between biomass and body weight of plankton in a steady state oceanic ecosystem. Limnol. Oceanogr., 31, 361-370.
Zhou, M. and M. E. Huntley. 1997. Population dynamics theory of plankton based on biomass spectra. Mar. Ecol. Prog. Ser., 157, 61-73.
Zhou, M. and K. S. Tande. 2002. Optical Plankton Counter workshop report. International Global Ocean Ecosystems Dynamics Program Report, No. 17, 67 pp.

For more Information about these data contact Dr. Zhou.

Last modified: June 29, 2006


Acquisition Description

We attached an Optical Plankton Counter (see Zhou and Tande, 2002) to the OSU towed body (SeaSoar) to make 3-dimensional mesoscale surveys (in a 100-km-wide coastal region from Newport, Oregon to Crescent City, California) aimed at determining the distribution and productivity of zooplankton in relation to their physical environment. The OPC provides counts and size estimates of zooplankton sized particles that pass through the instrument. The OPC data with other data sets (e.g., acoustics; ADCP-derived velocities) collected on these surveys, and from companion ships doing net sampling of zooplankton will allow estimation of growth and mortality rates of zooplankton using the biomass spectra method (Zhou and Huntley, 1997).

 

The OPC-CCS data are organized on the GLOBEC server by transect within cruise. The master (level0) page lists all of the cruises--there were two cruises in each of 2000 and 2002. Clicking on a cruise will show all of the casts collected and processed from that cruise (Level1), along with the start date and time of the transect. Clicking on a cast will bring up the Level2 file that shows OPC profile data. The raw data stream is averaged and output at every 4-m bin. The towed body undulates between a near-surface, shallow depth and a deeper depth (which hopefully is ABOVE the bottom). During normal ascent and descent rates of the SeaSoar, approx. 5-30 readings are averaged within every 4 m depth bin. At times of particularly slow depth change, more readings are included in these averages. Average latitude and longitude and date/time (GMT) for each depth bin are shown. OPC data for each reported depth bin include the total abundance of particles (no per m3), total carbon biomass (ug C/m3; estimated from equivalent spherical diameter (ESD) based on Rodriguez and Mullin (1986)), and a biomass spectrum (50 size classes of particles). The header for the biomass spectrum header (minimum of 0.33; maximum of 4.09) values are log10 based carbon intervals of individual particle size. There are 50 biomass size classes. The data for each of the spectra are the accumulated carbon of that size particle, normalized by the water volume, then normalized by the carbon interval, then expressed as log10 units. So the unit of biomass for each spectral class is log10(biomass spectrum (1/m3)).

Note 1: A fluorometer was interfaced with the OPC only for cruise NH0005. For all other cruises, the 'fluor' field value of 0.00 means 'no data'.

Note 2: Biomass spectrum contents: Header value of 0.33 means particles of ca. 10^0.33 = 2.138 ugC per particle. Largest particle size (header value 4.09 is particles of ca. 12302 ugC per particle)

Note 3: The original data contained values of '-99.00' to represent zero counts within any particular size (according to correspondence with Dr. Meng Zhou). BCO-DMO changed the '-99.00' values to '0.00' on 16 Oct 2012 so that they are not misinterpreted.


Processing Description

16 Oct 2012: BCO-DMO re-formatted the data by converting the size class columns into rows.


[ table of contents | back to top ]

Parameters

ParameterDescriptionUnits
cruiseid Cruise ID unitless
year Year unitless
transectTransect Description unitless
start_month_gmtMonth of Transect Start (GMT) unitless
start_day_gmtDay of Transect Start (GMT) unitless
start_time_gmtTime of Transect Start (GMT) unitless
elptimeElapsed time from Start Time. hours
month_gmt Month unitless
day_gmtDay unitless
time_gmtTime unitless
lat Latitude [decimal degrees] decimal degrees
lon Longitude [decimal degrees] decimal degrees
depth Depth of Observation [meters] meters
abundanceTotal Abundance [counts/m3] counts/m3
biomass_tot Total Biomass [ug C/m3] microgram C/meter^3
biovol Total Biovolume [mm3/m3] mm3/m3
fluor Chlorophyll [mg/m3] See Note 1 below. mg/m3
size_classSmallest Size Class of biomass spectrum. (See Note 2 above, under 'Processing Description'.)
biomassThe data for each of the spectra are the accumulated carbon of that size particle, normalized by the water volume, then normalized by the carbon interval, then expressed as log10 units. So the unit of biomass for each spectral class is log10(biomass spectrum (1/m3)).


[ table of contents | back to top ]

Instruments

Dataset-specific Instrument Name
SeaSoar
Generic Instrument Name
SeaSoar
Dataset-specific Description
We attached an Optical Plankton Counter (see Zhou and Tande, 2002) to the OSU towed body (SeaSoar) to make 3-dimensional mesoscale surveys(in a 100-km-wide coastal region from Newport, Oregon to CrescentCity, California) aimed at determining the distribution andproductivity of zooplankton in relation to their physical environment.
Generic Instrument Description
Towed, undulating vehicle usually equipped with a VPR, TAPS, PAR, CTD

Dataset-specific Instrument Name
Optical Plankton Counter
Generic Instrument Name
Optical Plankton Counter
Generic Instrument Description
An OPC provides quantitative measurements of abundance and sizes of mesozooplankton ranging between approximately 0.25 and 14 mm in Equivalent Spherical Diameter (ESD), and has the capability to integrate measurements from other sensors such as a CTD, fluorometer and Global Positioning System (GPS). It can be deployed on a variety of instruments such as SeaSoar, Aries, Scanfish, MOCNESS, a bongo net or simple towing frame. The data from an OPC are typically transmitted to a data acquisition computer through two conducting wires in a towing cable at real time, but it can also be modified to have an internal memory. Large amounts of data are produced. The procedures employed by OPC users vary from; i) estimating integrated biomass by integrating the OPC size distributions, ii) comparing size distributions between OPC and net samples, and iii) simply isolating a size region in the OPC size distribution which correspond solely to specific taxa, eg. Calanus spp.. from: Zhou, M., Tande, K., 2002. Optical Plankton Counter Workshop. GLOBEC Report 17, University of Tromso, Tromso


[ table of contents | back to top ]

Deployments

NH0005

Website
Platform
R/V New Horizon
Report
Start Date
2000-05-28
End Date
2000-06-13

NH0007

Website
Platform
R/V New Horizon
Report
Start Date
2000-07-27
End Date
2000-08-12

T0205

Website
Platform
R/V Thomas G. Thompson
Report
Start Date
2002-06-01
End Date
2002-06-17

R0208

Website
Platform
R/V Roger Revelle
Report
Start Date
2002-07-31
End Date
2002-08-19


[ table of contents | back to top ]

Project Information

U.S. GLOBEC Northeast Pacific (NEP)


Coverage: Northeast Pacific Ocean, Gulf of Alaska


Program in a Nutshell

Goal: To understand the effects of climate variability and climate change on the distribution, abundance and production of marine animals (including commercially important living marine resources) in the eastern North Pacific. To embody this understanding in diagnostic and prognostic ecosystem models, capable of capturing the ecosystem response to major climatic fluctuations.

Approach: To study the effects of past and present climate variability on the population ecology and population dynamics of marine biota and living marine resources, and to use this information as a proxy for how the ecosystems of the eastern North Pacific may respond to future global climate change. The strong temporal variability in the physical and biological signals of the NEP will be used to examine the biophysical mechanisms through which zooplankton and salmon populations respond to physical forcing and biological interactions in the coastal regions of the two gyres. Annual and interannual variability will be studied directly through long-term observations and detailed process studies; variability at longer time scales will be examined through retrospective analysis of directly measured and proxy data. Coupled biophysical models of the ecosystems of these regions will be developed and tested using the process studies and data collected from the long-term observation programs, then further tested and improved by hindcasting selected retrospective data series.



[ table of contents | back to top ]

Program Information

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


Coverage: Global


U.S. GLOBEC (GLOBal ocean ECosystems dynamics) is a research program organized by oceanographers and fisheries scientists to address the question of how global climate change may affect the abundance and production of animals in the sea.

The U.S. GLOBEC Program currently had major research efforts underway in the Georges Bank / Northwest Atlantic Region, and the Northeast Pacific (with components in the California Current and in the Coastal Gulf of Alaska). U.S. GLOBEC was a major contributor to International GLOBEC efforts in the Southern Ocean and Western Antarctic Peninsula (WAP).



[ table of contents | back to top ]

Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
National Oceanic and Atmospheric Administration (NOAA)

[ table of contents | back to top ]