Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Carbon, Nitrogen, and pigment fluxes from sediment trap arrays deployed in the Costa Rica Dome region of the Eastern Tropical Pacific Ocean during June and July 2010.

The sediment trap array was deployed at the beginning and recovered at the end of each experimental cycle.The array consisted of two VERTEX-style particle interceptor tube (PIT) crosspieces (Knauer et al. 1979, Stukel et al. 2013), deployed at what investigators initially thought to be the base of the euphotic zone (100 m on cycle 1, 90 m on other cycles) and 150 m. Each crosspiece held 8-12 cylindrical trap tubes, with an inner diameter of 70 mm and an 8:1 aspect ratio. Each tube also contained a baffle constructed of 14 smaller tubes that had been tapered at the top to ensure that all particles settling within the inner diameter of the outer tube would sink into the trap. Tubes were deployed with 2 L of a slurry comprised of 0.1-um filtered seawater, amended with an additional 50 g L-1 NaCl, and formalin (1% final concentration).

Upon recovery, the height of the interface between trap slurry and overlying water was immediately determined and the overlying water was gently removed with a peristaltic pump. Samples were then gravity filtered through a 200-um mesh Nitex filter and the contents of the filter were sorted under a dissecting microscope to remove mesozooplankton that were believed to have swam into the trap. The remainder of the >200-um particles were then re-combined with the <200-um. Individual tubes were split using a Fulsom split to allow replicate measurements of multiple different components of the sinking including organic C (Corg), N, and pigments (reported in Stukel et al. 2013). Samples for pigments were filtered through GF/F filters and extracted in 90% acetone for greater than 24 hours. Chlorophyll a and phaeopigments were then determined on a Turner Designs model 10 fluorometer (Strickland and Parsons, 1972). Samples for C and N were filtered through a GF/F filter and frozen at -80C. On land, filters were cut in half and acidified with HCl for 24 hours. They were then analyzed for C and N on the CHN analyzer at the SIO Analytical Facility.

Related publications and references:
Knauer, G.A., Martin, J.H., and Bruland, K.W. (1979) Fluxes of particulate carbon, nitrogen, and phosphorus
in the upper water column of the northeast Pacific. Deep Sea Research, 26A, 97-108. doi: 10.1016/0198-0149(79)90089-X
Stukel, M. R., Decima, M. ,Selph, K. E., Taniguchi, D. A. A., Landry, M. R. (2013) The role of Synechococcus in vertical flux in the Costa Rica upwelling dome. Progress in Oceanography 112-113: 49-59. doi: 10.1016/j.pocean.2013.04.003

Research was aimed at improved understanding of plankton dynamics, carbon and nutrient fluxes, and potential trace element limitation in the Costa Rica Dome region of the eastern tropical Pacific. The specific science objectives of the 2010 R/V Melville cruise (MV1008) were:
1) to assess grazing and trace metal/nutrient controls on primary production and phytoplankton standing stocks;
2) to quantify carbon and elemental fluxes and export rates from the euphotic zone; and
3) to measure microbial population, processes, stable isotope abundances associated with the OMZ and nitrite maxima.

Additional information about MV1008 can be found in the cruise report (PDF).

NOTE: The original proposal and award abstract are not relevant. The project was originally funded by NSF as experimental tests of phytoplankton controls in the Arabian Sea. Piracy concerns in the region led to the cancellation of the research cruise in 2009, and a Change of Scope request was approved to focus the project on related issues in the Costa Rica Dome (CRD).

Though this project is not formally affiliated with any large program, it aligns with IMBER's emphasis on community ecology and biogeochemistry, and the OCB focus on carbon-based measurements of production, grazing and export processes.

The BCO-DMO database includes data from IMBER endorsed projects lead by US funded investigators. There is no dedicated US IMBER project or data management office. Those functions are provided by US-OCB and BCO-DMO respectively.

The information in this program description pertains to the Internationally coordinated IMBER research program. The projects contributing data to the BCO-DMO database are those funded by US NSF only. The full IMBER data catalog is hosted at the Global Change Master Directory (GCMD). 

IMBER Data Portal: The IMBER project has chosen to create a metadata portal hosted by the NASA's Global Change Master Directory (GCMD). The GCMD IMBER data catalog provides an overview of all IMBER endorsed and related projects and links to datasets, and can be found at URL http://gcmd.nasa.gov/portals/imber/.

IMBER research will seek to identify the mechanisms by which marine life influences marine biogeochemical cycles, and how these, in turn, influence marine ecosystems. Central to the IMBER goal is the development of a predictive understanding of how marine biogeochemical cycles and ecosystems respond to complex forcings, such as large-scale climatic variations, changing physical dynamics, carbon cycle chemistry and nutrient fluxes, and the impacts of marine harvesting. Changes in marine biogeochemical cycles and ecosystems due to global change will also have consequences for the broader Earth System. An even greater challenge will be drawing together the natural and social science communities to study some of the key impacts and feedbacks between the marine and human systems.

To address the IMBER goal, four scientific themes, each including several issues, have been identified for the IMBER project: Theme 1 - Interactions between Biogeochemical Cycles and Marine Food Webs; Theme 2 - Sensitivity to Global Change: How will key marine biogeochemical cycles, ecosystems and their interactions, respond to global change?; Theme 3 - Feedback to the Earth System: What are the roles of the ocean biogeochemistry and ecosystems in regulating climate?; and Theme 4 - Responses of Society: What are the relationships between marine biogeochemical cycles, ecosystems, and the human system?

The Ocean Carbon and Biogeochemistry (OCB) program focuses on the ocean's role as a component of the global Earth system, bringing together research in geochemistry, ocean physics, and ecology that inform on and advance our understanding of ocean biogeochemistry. The overall program goals are to promote, plan, and coordinate collaborative, multidisciplinary research opportunities within the U.S. research community and with international partners. Important OCB-related activities currently include: the Ocean Carbon and Climate Change (OCCC) and the North American Carbon Program (NACP); U.S. contributions to IMBER, SOLAS, CARBOOCEAN; and numerous U.S. single-investigator and medium-size research projects funded by U.S. federal agencies including NASA, NOAA, and NSF.

The scientific mission of OCB is to study the evolving role of the ocean in the global carbon cycle, in the face of environmental variability and change through studies of marine biogeochemical cycles and associated ecosystems.

The overarching OCB science themes include improved understanding and prediction of: 1) oceanic uptake and release of atmospheric CO2 and other greenhouse gases and 2) environmental sensitivities of biogeochemical cycles, marine ecosystems, and interactions between the two.

The OCB Research Priorities (updated January 2012) include: ocean acidification; terrestrial/coastal carbon fluxes and exchanges; climate sensitivities of and change in ecosystem structure and associated impacts on biogeochemical cycles; mesopelagic ecological and biogeochemical interactions; benthic-pelagic feedbacks on biogeochemical cycles; ocean carbon uptake and storage; and expanding low-oxygen conditions in the coastal and open oceans.