Download or read book Temporal and Spatial Distribution of Endangered Juvenile Lost River and Shortnose Suckers in Relation to Environmental Variables in Upper Klamath Lake, Oregon written by U.S. Department of the Interior and published by CreateSpace. This book was released on 2014-03-30 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lost River sucker (Deltistes luxatus) and shortnose sucker (Chasmistes brevirostris) were listed as endangered in 1988 for a variety of reasons including apparent recruitment failure. Upper Klamath Lake, Oregon, and its tributaries are considered the most critical remaining habitat for these two species. Age-0 suckers are often abundant in Upper Klamath Lake throughout the summer months, but catches decline dramatically between late August and early September each year and age-1 and older sub-adult suckers are rare. These rapid declines in catch rates and a lack of substantial recruitment into adult sucker populations in recent years suggests sucker populations experience high mortality between their first summer and first spawn. A lack of access to, or abundance of, optimal rearing habitat may exacerbate juvenile sucker mortality or restrict juvenile growth or development.