GLOBEC MESOSCALE AND FINE-SCALE DISTRIBUTION OF JUVENILE SALMON AND ASSOCIATED BIOTA OFF OREGON AND NORTHERN CALIFORNIA
R. D. Brodeur, R.L. Emmett, W.T. Peterson [Northwest Fisheries Science Center], J.P. Fisher [Oregon State University], E. Casillas [Northwest Fisheries Science Center]
The opportunity exists to clearly identify the linkages between physical forcing, oceanographic conditions, the abundance and distribution of marine biota, and environmental characteristics that affect salmon survival and recruitment. We propose to compare and contrast juvenile salmon distributions and the associated biological community and oceanographic conditions spatially by sampling north and south of Cape Blanco. We will also sample juvenile salmon and associated biota within these regions on a finer scale.
We propose to conduct two 12 day broad-scale surveys for juvenile salmon and other associated species during early May and early September of 2000 and 2002. These cruises will be conducted in conjunction with other proposed sampling of the physics, nutrients, primary productivity, and zooplankton (net and acoustic sampling) to be carried out from another research vessel. Sampling stations will be set along pre-determined transects running from Newport to Eureka. Where possible, the same transects will be sampled as in the 1980s sampling, so that interdecadal comparisons in catch composition for the same months can be made. Following the broad-scale sampling, the vessel will coordinate with other planned process studies to examine juvenile salmon fine scale habitat utilization for an additional 8 day cruise during May and September. The fine-scale sampling would involve intense sampling at one or two locations and would be done in conjunction with physical, acoustic, and other biological sampling for prey from another vessel working in tandem with the salmon trawler. The proposed site for the May sampling will be a region of high productivity near Hecata Bank, OR. A second site for the September process study would be within some of the offshore jets south of Cape Blanco. Since we have access to the only comparable historical data set within the region (coastal Oregon), we also propose to compare and contrast juvenile salmon distribution and the associated biological community and oceanographic conditions from a temporal perspective (current conditions to conditions in 1979-1985).
We plan to hire the technician and begin to acquire and prepare all the equipment needed for the cruises. We will put the contract for the charter fishing boat out to bid in the winter for two 20 day cruises. We will coordinate with the Mesoscale and Process scientists to develop detailed plans for coordination among the vessels sea. We also plan to coordinate with other projects sampling juvenile salmon on the West Coast (NMFS Tiburon and Auke Bay Laboratories, Bonneville Power Administration, and Canadian scientists) to make sure our sampling times and methods are as compatible as possible. We will go to sea in both May and September to collect juvenile salmon along with their prey, predators, and potential competitors. Leaving from Eureka, we will spend the first 12 days sampling the mesoscale distribution of salmon and other biota and end in Newport, Oregon. Then after a day in port, we will continue the fine scale sampling in the areas designated for the process studies north and south of Cape Blanco, returning to Newport after 8 days of sampling. We will coordinate the processing of the biological samples once they arrive back in the laboratory and assist in the distribution of the samples and data to other proposed studies. We will enter the data from the first year cruises in the same format as the data already available from the 1980s and the ongoing BPA studies and begin a comparative analysis of the data sets.
This page was last updated on
March 14, 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