Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information

Mesopelagic microplankton abundances and carbon biomass

See Platform deployments for cruise specific documentation

  PI:              David Garrison and Marcia Gowing
  dataset:         Mesopelagic microplankton abundance and carbon biomass
  project/cruise:  Arabian Sea/TTN-050 - Process Cruise 5
  ship:            Thomas Thompson
 

Mesopelagic microplankton Methodology: 11 August 2004

Water samples were collected from 250 to 1000 or 1100 m depth. On cruises 
TTN043 and TTN045 aliquots totaling 4-9 liters per depth were taken from 
two 10 liter Niskin bottles. On cruises TTN050 and TTN054, entire contents 
(42-59 liters) of six 10 liter Niskin bottles per depth were used. Organisms 
were then concentrated within ~ 225 ml by the reverse filtration technique 
(Dodson and Thomas 1978) with 20 micrometer pore sized NitexTM mesh. 
Concentrated samples were measured and preserved in glass jars with a solution 
of 20% paraformaldehyde in 5% sodium borate to give a final concentration of 
2% paraformaldehyde. Entire samples were settled in the dark at 4 degrees °C 
in chambers to which a drop of a 1 mg per ml aqueous solution of DAPI 
(Coleman 1980) had been added. Entire chambers were examined at 150X using an 
epifluorescence microscope and a combination of tungsten and UV light. 
Microplankton (predominantly organisms 20-200 micrometers but sometimes larger) 
with a stained nucleus were counted and measured. Biomass was estimated by 
converting cell volumes to carbon using conversion factors for the various 
groups as described by Gowing et al. (2003).
References:

Coleman, A.W. 1980. Enhances staining of bacteria in natural environments by

fluorochrome staining of DNA. Limnol. Oceanogr. 25:948-951.
Dodson, A.N., W.H. Thomas. 1978. Reverse filtration. In: Sournia, A. (ed),

Phytoplankton Manual. UNESCO, Paris, pp. 104-122.
Gowing, M.M., D.L. Garrison, K.F. Wishner, C. Gelfman. 2003. Mesopelagic

microplankton of the Arabian Sea. Deep-Sea Res. I. 50:1205-1234.
PI note regarding multi-bottle sampling


 Note: _gt20 in the parameter names indicates organisms predominantly

 20-200 micrometers but sometimes larger in size.

The U.S. Arabian Sea Expedition which began in September 1994 and ended in January 1996, had three major components: a U.S. JGOFS Process Study, supported by the National Science Foundation (NSF); Forced Upper Ocean Dynamics, an Office of Naval Research (ONR) initiative; and shipboard and aircraft measurements supported by the National Aeronautics and Space Administration (NASA). The Expedition consisted of 17 cruises aboard the R/V Thomas Thompson, year-long moored deployments of five instrumented surface buoys and five sediment-trap arrays, aircraft overflights and satellite observations. Of the seventeen ship cruises, six were allocated to repeat process survey cruises, four to SeaSoar mapping cruises, six to mooring and benthic work, and a single calibration cruise which was essentially conducted in transit to the Arabian Sea.

The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.

The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).