This primary objective of these related
projects is to investigate the role of plankton community composition
on
controlling rates of carbon sequestration in the ocean interior.
It has been hypothesized that diatoms and
coccolithophorids contribute disproportionately to carbon sequestration
in the ocean interior. This is because diatoms are encased in a
silica frustule and coccolithophorids are surrounded by calcium
carbonate liths making them much denser than the surrounding seawater
and increasing their sinking rates. These increased sinking rates
shorten 'contact time' in the upper ocean and therefore reduce the
extent of remineralization (Armstrong et al. 2002). To test this
hypothesis we've examined the relationship between these two
phytoplankton groups and the 'degree of remineralization' estimated
from the exponential decay in sediment trap derived POC fluxes.
In Figure 1, we present the
model II linear regressions of the remineralization anomaly and
phytoplankton biomass anomaly for each group. For both diatoms
and coccolithophorids there is a significant negative correlation
suggesting that when these either of these two phytoplankton groups are
present in higher abundances, there is significantly less POC
remineralization.
Figure 1. Model II linear
regressions of the anomaly in the Martin remineralization coefficient
and phytoplankton biomass anomalies for coccolithophorids (left panel)
and diatoms (right panel).
I hope you return to this
page to see the progress that we are
making in this very important area of oceanographic research.
Collaborators on this
research:
Dr.
Brad Moran at University
of Rhode Island
Dr. Ken Buesseler at Woods Hole
Oceanographic Institution
Dr. Debbie Steinberg at Virginia
Institute of Marine Science
Dr. Dave Siegel at University of
California - Santa Barbara
Peer Reviewed
Publications Resulting
from this area of Research:
Acknowledging BATS funding:
Lomas
M. W.,
Bates, N. R. 2004. Interannual variability in primary production
partitioning
in the Sargasso Sea. Deep
Sea
Research I, 51:1619-1636.
(download
PDF)
Lomas,
M.W.,
Bates, N.R., Knap, A.H., Karl, D.A., Lukas, R., Landry, M.R., Bidigare,
R.R.,
Steinberg, D.A., and Carlson,
C.A.
2002. Refining our understanding of ocean
biogeochemistry and ecosystem functioning.
EOS, 83:559. (download
PDF).
Acknowledging Carbon and Water funding:
Research Awards
Supporting this Research:
The core BATS research program has
been funded equally by the Chemical and Biological Oceanography
programs of NSF. The specific
award numbers are OCE - 88-01089, OCE - 93-01950, OCE
- 96-17795, OCE
- 0326885.
This work is also funded as part of the Carbon and
Water program, Carbon Flux through the Twilight Zone: New Tools to
Measure Change. NSF Award
OCE-0628085.
Other Relevant
Research Links:
Ken
Buesseler's Twilight Zone Explorer (TZEX) web page
Nick Bates CO2
lab
at BIOS
U.S. JGOFS
Project Office
Integrated Marine
Biogeochemistry and Ecosystems Research (IMBER) Program
Surface Ocean Lower
Atmosphere Study (SOLAS) Program
Hawaii Ocean
Time-series (HOT)
Phytoplankton Community
Structure and Carbon Export in the Sargasso Sea.
Funding: NSF
Award Number(s): OCE - 0326885
and OCE - 0628085
PI's: (0326885) Knap,
Bates,
Lomas, Johnson;
(0628085) Buesseler, Steinberg, Siegel,
Lomas