Pathogen Screening Of Naturally Produced Yakima River Spring Chinook Smolts Yakima Klickitat Fisheries Project Monitoring And Evaluation Report 6 Of 7 2003 2004 Annual Report

Author : B. D. Watson
Publisher :
ISBN 13 :
Total Pages : 31 pages
Book Rating : 4.:/5 (316 download)

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Download or read book Comparing the Reproductive Success of Yakima River Hatchery and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation Report 4 of 7, 2003-2004 Annual Report written by B. D. Watson and published by . This book was released on 2004 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: In September of 2003, twenty-nine hatchery and twenty-eight wild spring chinook adults were placed into the observation stream located at the Cle Elum Supplementation Research Facility. In, addition 20 precocious males, 7 hatchery and 13 wild, were simultaneously released into the structure. As in previous years, the fish had small amounts of fin material removed prior to being introduced into the stream so that microsatellite DNA based pedigree analyses could be performed on their subsequent progeny. The entire 127 m long by 7.9 m wide stream was made available to this group of fish. Continuous behavioral observations were made while the females prepared nests and spawned. Moreover, standard measurements of adult longevity, spawning participation, water velocity, redd sizes, gravel composition, water temperature and flow were taken. Fry produced from these fish started to emigrate from the stream in early January 2004. They were trapped and sub-sampled for later microsatellite DNA analyses. In mid May of 2004 fry emergence from the channel was complete and residual fish were captured by seine and electro-fishing so that the entire juvenile population could be proportionately sampled. Audiotape records of the behavior of wild and hatchery adults spawning in the observation stream in 2001 were transcribed into continuous ethograms. Courting, agonistic, and location data were extracted from these chronological records and analyzed to characterize the reproductive behavior of both hatchery and wild fish. In addition, a ''gold standard'' pedigree analysis was completed on the fry originating from the adults placed into the observation stream in 2001. Behavioral and morphological data collected on hatchery and wild males were linked to the results of the pedigree analysis to ascertain what factors affected their reproductive success (RS) or capacity to produce fry. Individual RS values were calculated for each male placed into the observation stream and the coefficient of variation calculated from these values was greater than 100%. To determine what might be responsible for this degree of variation we examined the relative importance of a variety of physical and behavioral traits. Relative body size, for example, was found not be an important predictor of reproductive success. Instead, the capacity to court females and dominate sexual rivals was directly associated with male RS. However, males that had low dominance scores were also successful at producing offspring. These individuals utilized alternative behavioral strategies to gain close proximity to females and were successful in their attempts to fertilize eggs. Observations made on the color patterns of males showed dominance was closely linked with the possession of an overall black or dark brown color pattern. In addition, we discovered that males that had multiple mates achieved higher RS values than those who spawned with fewer females. The approach we are taking to compare the reproductive competency of hatchery and wild fish is to first determine the factors that are strongly linked to reproductive behavior and then assess whether significant differences occur in the expression of these traits based on the fish origin. Transcriptions of audiotapes are continuing and a second gold standard pedigree analyses on the fry produced from adults placed into the observation stream in 2002 is nearing completion. Future work will be directed at discovering the factors that affect female RS values. In the fall of 2004 we will again liberate hatchery and wild fish simultaneously into the entire observation stream to continue our efforts to objectively determine if differences in RS are caused by fish origin.