BONGO LOPC log from R/V New Horizon cruise NH1008 in Monterey Bay, near MBARI buoy M1 (36.747?N, 122.022?W); 2010 (GATEKEEPERS project)

Version: 24 September 2012
Version Date: 2012-09-24

» Zooplankton feeding at the base of the particle maximum: Gatekeepers of the Vertical Flux? (GATEKEEPERS)
Checkley, David M.University of California-San Diego (UCSD-SIO)Principal Investigator, Contact
Dagg, MichaelLouisiana Universities Marine Consortium (LUMCON)Co-Principal Investigator
Jackson, George A.Texas A&M University (TAMU)Co-Principal Investigator
Gegg, Stephen R.Woods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Dataset Description


From the original .xls file:
NH1008 Bongo-LOPC
Mesh    Port/LOPC    Stb.        Meter No.    Intercept    0.2586
Net No.    CB5507        CB3506        B15049        Slope    0.0467

How To Do A BONGO Tow (.pdf)

BONGO Tow Sheet Example

Acquisition Description

Processing Description

BCO-DMO Processing/Edits
- Generated from  original file: "Bongo_LOPC_log_20Sep2012_JFB.xls" contributed by Jessica Forrest-Baldini
- Dates reformatted to YYYYMMDD
- Times reformatted to HHMM
- ISO DateTime format generated
- "NaN" and "n/a" replaced with "nd" (no data)
- BCO-DMO compatible parameters generated

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Recorded_StationBONGO/LOPC Recorded Station Dimensionless
Order_OccupiedBONGO/LOPC Order Occupied Dimensionless
File_NumberBONGO/LOPC File Number Text
LatitudeTow Latitude (South is negative) decimal degrees
LongitudeTow Longitude (West is negative) decimal degrees
ISO_DateTime_Local_Begin_TowBegin Tow Date/Time (PDT) ISO formatted YYYY-MM-DDTHH:MM:SS.xx[+/-TZ]
Date_Begin_TowBegin Tow Date (PDT) YYYYMMDD
Time_Begin_TowBegin Tow Time (PDT) HHMM
ISO_DateTime_Local_End_TowEnd Tow Date/Time (PDT) ISO formatted YYYY-MM-DDTHH:MM:SS.xx[+/-TZ]
Date_End_TowEnd Tow Date (PDT) YYYYMMDD
Time_End_TowEnd Tow Time (PDT) HHMM
Sinking_MinSinking Minutes Minutes
Sinking_SecSinking Seconds Seconds
Towing_MinTowing Minutes Minutes
Towing_SecTowing Seconds Seconds
Total_MinTotal Minutes Minutes
Total_SecTotal Seconds Seconds
Total_TimeTotal Time Seconds
Wire_OutWire Out Meters
Flowmeter_FinalFlowmeter Final (10counts=1rev) Counts
Flowmeter_InitialFlowmeter Initial (10counts=1rev) Counts
Flowmeter_DiffFlowmeter Difference (10counts=1rev) Revolutions
Frame_AreaFrame Area meters2
RPSRevolutions Per Second rev/second
MrevRevolutions Per Minute rev/minutes
Volume_FilteredVolume Filtered meters3

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Dataset-specific Instrument Name
Bongo Net
Generic Instrument Name
Bongo Net
Generic Instrument Description
A Bongo Net consists of paired plankton nets, typically with a 60 cm diameter mouth opening and varying mesh sizes, 10 to 1000 micron. The Bongo Frame was designed by the National Marine Fisheries Service for use in the MARMAP program. It consists of two cylindrical collars connected with a yoke so that replicate samples are collected at the same time. Variations in models are designed for either vertical hauls (OI-2500 = NMFS Pairovet-Style, MARMAP Bongo, CalVET) or both oblique and vertical hauls (Aquatic Research). The OI-1200 has an opening and closing mechanism that allows discrete "known-depth" sampling. This model is large enough to filter water at the rate of 47.5 m3/minute when towing at a speed of two knots. More information: Ocean Instruments, Aquatic Research, Sea-Gear

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R/V New Horizon
Start Date
End Date
Collaborative Research: Zooplankton at the Base of the Particle Maximum: Gatekeepers of the Vertical Flux?: Deployment and recovery of SOLOPCs in Monterey Bay, plus CTD and MOCNESS deployments in Monterey Bay Cruise information and original data are available from the NSF R2R data catalog. Figure 1. R/V New Horizon Cruise NH1008 GATEKEEPERS [click on the image to view a larger version]

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Project Information

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

Coverage: Monterey Bay, CA and waters offshore

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

A range of observations suggest that zooplankton act as gatekeepers for material leaving the euphotic zone. This study will investigate the interactions of zooplankton with other particles using a suite of autonomous and tethered instruments in conjunction with finescale water sampling. The SOLOPC (Sounding Oceanographic Observer with Laser Optical Plankton Counter) will be the autonomous instrument and provide hourly profiles of zooplankton and other particles. Previous sampling with the SOLOPC indicated a diel cycle of production and abundance of particles in the euphotic zone and their sinking and consumption, presumably by zooplankton observed at the base of the particle abundance maximum. The SOLOPC senses particles, including zooplankton and aggregates, and measures their equivalent spherical diameters which can be used to compute particle size spectra. However, it is difficult to use the SOLOPC to distinguish among particle types, such as copepods, larvaceans, and aggregates, particularly if they are small. The research will include an intensive field study that will take place in Monterey Bay and use adaptive sampling to observe near SOLOPCs with a new, AUV-borne imaging system, ship-based CTD and MOCNESS sampling, and MBARI's ROV Ventana. The investigators will alter a SOLOPC to be stationary relative to an isopycnal and use the particle counts that it accumulates to calculate a flux spectrum. They will combine the flux and concentration spectra to estimate particle sinking velocities as a function of particle diameter. Zooplankton feeding in the water column will be estimated by analyzing the gut fluorescence of animals caught in zooplankton nets and by counting the distribution of fecal pellets in water samples. Results will enhance the understanding of the role of the zooplankton as gatekeepers in the vertical flux of particles and, hence, the biological pump. The study will also provide new insight into factors that affect zooplankton behavior and ecology.

Collaborating institutions include SIO, TAMU, LUMCON, MBARI, BIO, and Université Paris VI. The SOLOPC, modified to measure flux as well as profile, and REFLICS are intended for acquisition and use by other researchers worldwide. The understanding we gain of role of the zooplankton as gatekeepers of the vertical flux will contribute valuably to understanding of the biological pump and the carbon cycle.

Jackson, GA and DM Checkley Jr. "Particle size distributions in the upper 100 m water column and their implications for animal feeding in the plankton," Deep-Sea Research, 2011.

Figure 1. R/V New Horizon Cruise NH1008 GATEKEEPERS
[click on the image to view a larger version]

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Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)

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