Salmon studies in interior Alaska, 1997
By: by Lisa Stuby and Matthew J. Evenson.
Contributors: Evenson, Matthew J.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 98-11.
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: 75
Subjects: Salmon -- Alaska, Interior -- Statistics.; Fish populations -- Alaska, Interior -- Statistics.; Fish-culture -- Alaska, Interior -- Statistics.
Genres: Statistics.
Description: Escapements of chinook salmon (Oncorhynchus tshawytscha) in the Salcha, Chena and Chatanika rivers near Fairbanks, Alaska were estimated using either mark-recapture and/or counting tower techniques. Tower count estimates were 18,514 (SE=1,043) chinook salmon for the Salcha River and 13,390 (SE=699) for the Chena River. Mark-recapture studies gave estimates of 10,810 (SE=1,160) chinook salmon for the Chena River and 3,809 (SE=1,507) for the Chatanika River. Results of a two-tailed z-test failed to reject the hypothesis (P=0.06) that the tower count estimate for the Chena River is equivalent to the mark-recapture estimate. Aerial survey counts of chinook salmon during the periods of maximum escapement were 3,458 for the Salcha River and 3,495 for the Chena River. These estimates were 0.19 of the Salcha River tower estimate, and 0.32 and 0.26 of the Chena River mark-recapture and tower estimates, respectively. Females comprised 0.48 (SE=0.03) of a sample of chinook salmon carcasses collected in the Salcha River during late August. Proportions of female chinook salmon estimated from mark-recapture experiments were 0.26 (SE=0.04) and 0.09 (SE=0.05) for the Chena and Chatanika rivers, respectively. The majority of males examined from the Salcha River were age 1.4 (0.49), with the rest comprising ages 1.2 (0.26), 1.3 (0.24), and 1.5 (0.01). For the Chena and Chatanika rivers, the majority of males were age 1.2 (0.61) and (0.75), respectively. Females were characteristically older. For the Salcha, Chena and Chatanika rivers the majority of females were age 1.4. Proportions of age 1.4 females were 0.90, 0.93, and 0.80 for the three rivers, respectively. A portion of the Salcha and Chena rivers chum salmon (Oncorhynchus keta) escapement was also estimated during the tower counts. Estimated escapement of chum salmon through 7 August was 35,948 (SE=819) for the Salcha River and 9,439 (SE=589) through 3 August for the Chena River. Escapement of coho salmon (Oncorhynchus kisutch) was measured in the mainstream Delta Clearwater River near Delta Junction, Alaska, by means of aerial and boat counts. The boat count of the mainstem river was 11,525 on 24 October, and the helicopter count on 22 October of tributaries which were inaccessible by boat was 2,375. Total escapement of was 13,900. A total of 391 coho salmon were sampled on two different occasions for age, sex and length. Females comprised 0.46 of total fish sampled. The majority of the samples were age 2.1.
Notes: "July 1998".

Includes bibliographical references (p. 52-55).

Also issued online.