Comparison of counting tower estimates and digital video counts of coho salmon escapement in the Ugashik Lakes

Metadata Updated: October 10, 2019

In 2001, the U.S. Fish and Wildlife Service King Salmon Fish and Wildlife Field Office began a counting tower project to estimate coho salmon Oncorhynchus kisutch escapement into the Ugashik lakes using standard protocols developed for sockeye salmon O. nerka. Because the coho salmon run size was much smaller than the sockeye salmon run, there was concern that the standard protocols may be biased for coho salmon. In 2002, we compared escapement estimates of coho salmon obtained from the counting tower using standard protocols to counts obtained from a video camera that recorded images of all fish that passed the site. Over the 152 hours that we sampled using both methods, we counted 478 coho salmon from the video files while the counting tower estimated 426 coho salmon. A sign test indicated a significant difference in the frequency of positive and negative differences between the two methods (Z = 3.53, P < 0.01). The overall tower estimate was only 52 fish less than the total video count, and the difference between the two methods did not exceeded five fish in 87% of the hourly comparisons. Recognizing the inherent variability associated with counting tower estimates, they appear to be an adequate management tool for obtaining baseline escapement data on coho salmon into the Ugashik lakes.

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Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Created Date May 1, 2019
Metadata Updated Date October 10, 2019

Metadata Source

Harvested from DOI CKAN Harvest Source

Additional Metadata

Resource Type Dataset
Metadata Created Date May 1, 2019
Metadata Updated Date October 10, 2019
Publisher Fish and Wildlife Service
Unique Identifier FWS_ServCat_84964
Brent Frakes
Maintainer Email
Public Access Level public
Bureau Code 010:18
Metadata Context
Metadata Catalog ID C:\Program Files (x86)\FWS\DataStore\Application\OpenData\FWS_ServCat_v1_1.json
Schema Version
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Harvest Source Id 34ce571b-cb98-4e0b-979f-30f9ecc452c5
Harvest Source Title DOI CKAN Harvest Source
Data First Published 2005-04-01
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Program Code 010:094, 010:028
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Source Hash 69412094851d3ed43686da61c9773cc882c56e06
Source Schema Version 1.1
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Category "Unpublished Report"

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