Informative Correlations Among Metrics of Yellowstone Lake Cutthroat Trout Caught by Two Quantitative Methods Across Three Recent Decades
Author: Lynn Robert Kaeding
Publisher:
Published: 2013
Total Pages: 5
ISBN-13:
DOWNLOAD EBOOKThe Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri (YCT) of Yellowstone Lake, in Yellowstone National Park, Wyoming, is an iteroparous fish and obligate stream spawner. The size and several other attributes of the annual YCT spawning run in one lake tributary, Clear Creek, have been periodically estimated for several decades. The trends in that run's metrics have been assumed to depict the trends in the lake's YCT population as a whole, although such associations had not been substantiated by statistical analyses. The present study revealed strong correlations between metrics of YCT in the run (years 1977-2007) and of "prespawner" YCT (i.e., mature fish whose excised gonads indicated that the fish would have spawned the next year) caught in gill nets set in various lake locations the preceding fall. Data for both capture methods also revealed a negative effect of spawning population density on YCT somatic growth, which is known to be positively associated with fecundity. This study showed that most metrics of YCT in the Clear Creek spawning run were indicative of those of prespawner YCT in Yellowstone Lake and aided the development of population models that are needed to determine the causal factors in the recent, three-decade population decline of YCT.