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Project Information

Title: Run Reconstruction and Life History Models

Project Year and Number: 1992: FS28

Other Fiscal Years and Numbers for this Project: 1991: FS28, 1990: FS28

Principal Investigator (PI): Hal Geiger, Alaska Department of Fish & Game

Assisting Personnel: Jeremy Collie, Terry Quinn, Bill Templin

Research Location: Prince William Sound

Restoration Category: Damage Assessment

Injured Resources Addressed: Pink Salmon

Abstract: This project will quantify the injury to the wild salmon stocks of the Prince William Sound from the Exxon Valdez oil spill. Understanding this injury is necessary for continuing fishery management of injured stocks and rational restoration. One of the main tools being developed to reach this goal is a run reconstruction model. This model will be used to estimate production from each of the Prince William Sound wild stock groups, both before and after the oil spill. The adult tagging study described below will provide information that will improve the already good foundation of this run reconstruction model.

Because of extremely large increases in hatchery production, Prince William Sound as a whole is producing salmon at all-time record levels. These hatchery salmon are essentially inputs to the fishing industry. The wild stocks, which are an important component in the natural ecosystem, originate from a multitude of natal stream locations throughout the Prince William Sound. The aggregate hatchery component of the total production can be determined with coded-wire tags. The estimated percent of the hatchery pink salmon in the Prince William Sound harvest has fluctuated from slightly over 50% in 1987 to in excess of 90% in 1988 and the gap in proportions of wild and hatchery contributions to the run seems to be getting bigger.

The stock specific origins of the wild portion of the harvest are unknown. This information is necessary to understand oil spill injury to manage the fishery, to protect affected wild stocks, and to begin other restoration measures. The run reconstruction model is a tool for detecting these stock specific origins. This model is a mathematical description of wild stock return patterns, accounting for removal by harvest in a series of mixed stock fisheries. This accounting of the harvest, by stock, in mixed stock fisheries is the heart of the model.

The University of Alaska, Juneau Center for Fisheries and Ocean Sciences, has developed a run reconstruction model for this project for a single fishing district, although work continues on a computer implementation. The next level of complexity, the multidistrict model, requires spatial and temporal information on the migratory movement of pink salmon in Prince William Sound. Data from previous adult tagging studies could not be used to complete this task. Exhaustive efforts were made to use the historical data. These data have proved unsuitable because they are too incomplete: no record was made of the fraction of the fishery sampled to collect those tags that were recovered. An adult tagging study will take place during the 1992 season to estimate these key missing parameters. The study will use radio or sonic tags on a small number of fish. Rather than infer movement patterns from the recovery of a large number of tags, the study will attempt to directly observe the movement of a smaller number of fish.


Geographic Regions Prince William Sound
Species Fish - Salmon
Technological Methods Modeling
Radio Tagging

Proposal: PDF Not Available

Funding Recommendations: View

Funding Detail For: 1992

Quarterly Project Tasks For: 1992

Annual Report: 1992: Not Applicable

Final Report: View

Publications from this Project: None Available

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Project Number Proposal Annual Reports Final Report Data
1991: FS28 Not Available 1991: Not Applicable
See Project FS28 See Project FS28
1990: FS28 Not Available 1990: Not Applicable
See Project FS28 See Project FS28