Pilot Monitoring off Oregon for Climate Change Studies in the Eastern North Pacific. (Smith, R. L., Huyer, A., Wheeler, P., Peterson, W., Kosro, M., Barth, J. A. [All at Oregon State Univ.]) To understand the effects of climate variability on marine life in the eastern North Pacific requires that we know what the oceanic environment is, how it is changing, and what the oceanic environment was in the past. There is evidence that the ecosystems over the continental margins of the eastern North Pacific have changed since a "climate shift" occurred about 1976. Salmon production is different since 1976, and interannual changes in the coastal ocean clearly affect the productivity and survival of biota. Subsurface oceanic conditions off central Oregon in the anomalously warm years of 1983 and 1992 were unique when compared with data from the 1960s; no years in the 1960s had as warm temperatures at depth (50 to 200 m) as those in 1983 and 1992. Seasonal monitoring had been conducted for the decade 1961-71, but with very limited hydrographic data since 1976, we aren't able to say whether the mean conditions for non-anomalous years since 1976--since the "climate shift"--are different than earlier years. Measurements are needed now to compare with the good data base that exists for the 1960s.

This proposal seeks to initiate a pilot monitoring program along two transects off the central Oregon coast (44.6° and 43.2°N) where regular hydrographic sampling programs have existed in the past. We plan five cruises per year to monitor the hydrography, nutrients, chlorophyll, and zooplankton species composition and abundance at biologically-important times of year: Winter (Dec-Feb) when winds are normally favorable for downwelling and shelf currents are normally northward, chlorophyll is low, and the copepod Calanus are in diapause or just emerging from diapause and have not begun their seasonal population increase; Early Spring (March/April), at or soon after the spring transition that marks the seasonal onset of upwelling, and before juvenile salmon enter the ocean; Late Spring (May/June), when the southward flow is fully established, the phytoplankton is likely to be in full bloom, euphausiid abundances normally begin their seasonal increase and salmonids are entering the ocean; Summer (July/August), near the height of the upwelling season and the peak of copepod abundance; and Autumn (Sept/Oct), when seasonal heating has ended, coastal convergence has begun, coastal copepods are still abundant, and Calanus species are preparing for diapause.

This page was last updated on March 15, 2007.

Maintained by:
Hal Batchelder
College of Oceanic and Atmospheric Sciences
Oregon State University
Corvallis, OR 97331-5503
phone: 541-737-4500; FAX 541-737-2064