Lake Roosevelt Fisheries Evaluation Program; Assessment of the Lake Roosevelt Walleye Population: Compilation of 1997-1999 Data, 1999-2000 Annual Report.

PDF Version Also Available for Download.

Description

A walleye mark-recapture study was conducted on Lake Roosevelt between 1997 and 1999. The primary objective of the study was to describe the status and biological characteristics of the walleye population in Lake Roosevelt by determining its abundance, movement patterns, age structure, growth, condition, and mortality. The abundance estimates were also to be used to estimate the consumptive impact of walleye on stocked kokanee and rainbow trout. Walleye were collected by electrofishing and angling. Each walleye was tagged with an individually numbered Floy tag. The Jolly-Seber model was used to estimate the size of the walleye population in 1999, using ... continued below

Physical Description

70 pages

Creation Information

McLellan, Jason; McLellan, Holly & Scholz, Allan March 1, 2002.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

A walleye mark-recapture study was conducted on Lake Roosevelt between 1997 and 1999. The primary objective of the study was to describe the status and biological characteristics of the walleye population in Lake Roosevelt by determining its abundance, movement patterns, age structure, growth, condition, and mortality. The abundance estimates were also to be used to estimate the consumptive impact of walleye on stocked kokanee and rainbow trout. Walleye were collected by electrofishing and angling. Each walleye was tagged with an individually numbered Floy tag. The Jolly-Seber model was used to estimate the size of the walleye population in 1999, using each year of the study as a mark-recapture occasion. Mark-recapture data collected in 1998 was re-analyzed in 1999 with the data pooled in various combinations, using closed and open population models, in an attempt to provide an estimate of walleye abundance that was unbiased, accurate, and more precise. Minimum distances traveled between mark and recapture location by tagged walleye were determined from tag returns. Over the three study years, a total of 12,343 walleye {ge} 150 mm TL were collected by Eastern Washington University (EWU), Spokane Tribe of Indians, and Washington Department of Fish and Wildlife, and of those, 10,770 were tagged and released. Of the 10,770 walleye marked and released, 775 were recaptured and returned to EWU. The 1999 abundance estimate ({+-} standard error) for walleye {ge} 150 mm TL was 129,183 ({+-} 45,578) and the estimated abundance ({+-} standard error) of walleye {ge} 200 mm TL was 101,508 ({+-} 35,603). A total of 38 population estimates were calculated for 1998. The estimates of the abundance of walleye {ge} 150 mm TL in Lake Roosevelt ranged from 84,335 to 180,568 fish. Estimates of the size of the walleye population {ge} 200 mm TL ranged from 14,971 to 173,702. The 1999 estimate, which used each study year as a mark-recapture occasion, was biased due to unequal capture probabilities. If biases were eliminated, the annual sampling strategy may be the most cost-effective. Of the reanalyzed 1998 estimates, the Schnabel corrected for tag loss and recruitment and the Jolly-Seber estimate, both calculated with the 200 mm minimum length, were recommended for modeling walleye consumption. Minimum distances traveled between mark and recapture location by tagged walleye marked on the spawning run ranged from 0 to 245 km over a range of 11 to 486 days. Minimum distances traveled between mark and recapture location by tagged walleye marked during the summer/fall ranged from 0 to 217 km over a range of 8 to 788 days. Walleye exhibited seasonal movement trends that included a migration to the spawning area in the upper Spokane River Arm in the spring, with peak spawning occurring in April and May, and a migration following spawning to summer habitats. Once at the summer habitat, walleye appeared to establish summer home ranges (SHR). Walleye collected in Lake Roosevelt in 1999 ranged in age from 0 to 8. Mean instantaneous and mean annual mortality were estimated at 0.62% and 46%. Mean condition factor (K{sub TL}) of the 343 walleye measured and weighed in 1999 was 0.83 (SD = 0.13). Walleye mortality rates appeared to be relatively stable. Mortality and growth were average when compared to other walleye producing waters. Walleye condition was low when compared to condition factors in 1980-83, 1988, 1989, and 1990. The K{sub TL}'s of walleye from Lake Roosevelt were slightly below average when compared to other walleye populations.

Physical Description

70 pages

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: DOE/BP-32148-10
  • Grant Number: None
  • DOI: 10.2172/961899 | External Link
  • Office of Scientific & Technical Information Report Number: 961899
  • Archival Resource Key: ark:/67531/metadc933721

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • March 1, 2002

Added to The UNT Digital Library

  • Nov. 13, 2016, 7:26 p.m.

Description Last Updated

  • Dec. 9, 2016, 10:17 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 6

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

McLellan, Jason; McLellan, Holly & Scholz, Allan. Lake Roosevelt Fisheries Evaluation Program; Assessment of the Lake Roosevelt Walleye Population: Compilation of 1997-1999 Data, 1999-2000 Annual Report., report, March 1, 2002; Portland, Oregon. (digital.library.unt.edu/ark:/67531/metadc933721/: accessed September 25, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.