Burbot research in rivers of the Tanana River drainage, 1997
By: by Matthew J. Evenson.
Contributors: Alaska. Division of Sport Fish.
Series: Fishery data series -- no.98-38.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1998
Place of publication: Anchorage
Language: eng
Number of pages: 58
Subjects: Burbot -- Alaska -- Tanana River Region -- Statistics.; Fish stock assessment -- Alaska -- Tanana River Region.; Fish populations -- Alaska -- Tanana River Region -- Measurement.
Description: As part of an ongoing stock assessment program, burbot Lota lota were sampled in two river sections during 1997, one each in the Tanana and Chena rivers, representing the areas where most harvest occurs. These sections have been sampled annually since 1986 and 1988, respectively. A systematic sampling design was used, whereby hoop traps were set and moved daily over an eight-day period. Estimates of mean catch per unit effort, mean length, length distributions, and proportions of catch for three size categories were calculated. Estimates for each were within the range of observed values from previous sampling years. Catch-age analysis was investigated as a technique to estimate fishing mortality and exploitable abundance of burbot in the Tanana River drainage. However, the current model framework appears to be unstable and is not recommended for generating reliable estimates of abundance for burbot in the Tanana River drainage. The catch-age model results showed a decreasing trend in exploitable abundance from 1987 to 1995 with a slight upward trend in 1996. Fishing mortality estimates for fully recruited burbot were generally low and ranged from 0.04 to 0.17. Improvements in the catch sampling program, a longer time series of data, and more accurate estimates of fishing effort are needed to improve the model estimates. Other models that incorporate length information from the index sampling or catch should be investigated.
Notes: "December 1998"

Includes bibliographical references (p. 38-40).

Also issued online.

Partially funded by Federal Aid in Sport Fish Restoration Act (16 U.S.C. 777-777K) Project F-10-13, Job no. R-3-4(b).