U.S. Global Ocean Ecosystems Dynamics (GLOBEC)
Northeast Pacific
ISSUE
For resource managers, it is critical to understand the effects of climate
change on the distribution, abundance, and production of marine animal populations
in areas important to the regional and national economies. In the NE Pacific
Ocean, there is a close connection between the ecosystem dynamics in both
of its gyres - the California Current System (CCS) and the Coastal Gulf of
Alaska (CGOA). Tide gauge and satellite altimeter data suggest that the strengths
of the boundary currents in these gyres covary out of phase on annual and
inter-annual time scales. On inter-decadal time scales, there are data suggesting
that zooplankton and salmon covary out of phase in the two boundary currents.
The fluctuations in these populations, and others, coincide with basin-scale
physical changes in atmospheric forcing and ocean conditions, although the
mechanisms responsible for the coupled variability are not known.
APPROACH
The NE Pacific Program seeks (1) to understand the effects of climate variability
and climate change on the distribution, abundance, and production of marine
animals (including salmon and other commercially important living marine resources)
in the eastern North Pacific; and (2) to embody this understanding in diagnostic
and prognostic models, capable of characterizing ecosystem dynamics and responses
on a range of time scales, including major climatic fluctuations.
.
Two research programs are active in GLOBEC NEP: one off the coast of Oregon
in the northern California Current System (CCS), and one in the coastal Gulf
of Alaska. The Oregon program is coordinated with NSF's
Coastal Ocean Processes effort, which studies cross-shelf transport processes
in the CCS. The GLOBEC NEP program also complements the COP-funded Pacific
Northwest Regional Ecosystem study, which focuses on a research area nearer
to shore.
ACCOMPLISHMENTS
The 1997-1998 strong El Nino conditions provided an opportunity to evaluate
the effects of oceanic variability on coupled physical-biological systems
in the CCS. Long-term observation lines were in place in the northern California
Current off of the Oregon coast, and in the coastal Gulf of Alaska. Investigators
accelerated their planned sampling schedule to monitor the El Nino conditions.
Comparisons of 1997-1998 El Nino data with previous El Nino events, the subsequent
La Nina event, and data from non-El Nino years will help to identify which
factors are strongly dependent on El Nino/La Nina, and how future El Nino/La
Nina conditions may affect variability in salmon abundance. With improved
prediction of ENSO events, and the resulting consequences to fishery populations,
management can become more adaptive in response to natural variability.
In 2000, extensive field studies began off the coast of Oregon to determine
the physical and biological characteristics that affect the oceanic life phase
of Pacific salmon. Sampling occurred from Newport, OR south to Crescent City,
CA, and included a three-ship operation comprising measurements of the physical
environment, the phytoplankton, zooplankton, juvenile fish, and top predators
(marine mammals and birds) that make up the ecosystem. Better understanding
of this coastal oceanic environment will allow better planning and protection
of the salmon resources in this area.
In 2001, the GLOBEC NEP program began field work in the Coastal Gulf of Alaska
in a companion study. GLOBEC researchers are investigating the potential effects
of predicted increases in precipitation at high latitudes and increased melting
of snow and ice. Because climate change effects are anticipated to be greater
at higher latitudes, U.S. GLOBEC Studies in the Gulf of Alaska offer important
opportunities to study potential impacts of global warming on marine ecosystems.
Not only will this provide better information for the Alaskan salmon resources,
it will allow intercomparisons of the two systems to investigate the covariation
between the two systems, and the effects of climate variability on the two
systems.
Related Websites
For more information, contact:
Elizabeth Turner
CSCOR/Coastal Ocean
Program
phone: 301-713-3338
e-mail: coastalocean@noaa.gov
Last Updated:
October 23, 2002
