| |
Coastal Ocean Projects Program/River Influences on Shelf Ecosystems
Columbia River, Oregon/Washington
Dr.
Raphe Kudela from the University of Santa Cruz
BACKGROUND
RISE (River Influences on Shelf Ecosystems) is a 5-year interdisciplinary
study of the Columbia River plume, funded by the Coastal Ocean Program
of the National Science Foundation. The UCSC component of RISE includes
the Kudela Lab. Kudela’s group is responsible for remote sensing,
bio-optics and phytoplankton productivity estimates using stable
and radiotracer techniques (http://oceandatacenter.ucsc.edu/RISE/).
This study addresses three hypotheses during a 5-year program (2003-2008):
*During upwelling the growth rate of phytoplankton within
the plume exceeds that in nearby areas outside the plume being fueled
by the same upwelling macronutrients.
*The plume enhances cross-margin transport of plankton and
nutrients.
*Plume-specific nutrients (iron and silicate) alter and enhance
productivity on nearby shelves.
Figure 1. Satellite image of chlorophyll a distribution at the mouth
of the Columbia River http://oceanweb.ocean.washington.edu/rise/index.htm
STUDY SITE
RISE focuses on the highly productive Eastern Boundary river plume
originating from the Columbia River located in the Pacific Northwest.
Chlorophyll and productivity are not uniform along the Pacific Northwest
coast– they are higher in the Columbia River plume and over the
shelf north of the river mouth compared with the region south of
the river mouth. The Columbia River itself provides little nitrate
to the coast, although it does supply large amounts of silicate
and as much dissolved iron as the Mississippi.
PROTOCOL
The PhytoFlash was integrated into the CIMT CTD January 2006 shipboard
survey. Water samples were collected with Niskin bottles and processed
for extracted chlorophyll a.
Graph 1. The PhytoFlash was deployed as part of the NSF sponsored
RISE program off the Oregon/Washington coast. Samples were collected
from Niskin bottles, dark adapted for 30 minutes, and then run in
laboratory mode. As expected there was a decrease in FvFm moving
from onshore to offshore, and from surface to depth.
Dr. Raphael Kudela, Associate Professor
Ocean Sciences & Institute for Marine Sciences
University of California Santa Cruz
1156 High Street, Santa Cruz, CA 95064
|
