It is current practice to transport juvenile anadromous salmonids in transplantation and to help them bypass dams. Essentially nothing is known about the effects that transportation could have on the ability of the fish to outmigrate and be fit for survival in the marine environment. Procedures involved in transporation subject...
Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes for agricultural and urban development may have contributed to a decline in salmon abundance in the Pacific Northwest, prompting efforts to...
The myxozoan parasite, Ceratomyxa shasta, is the most significant pathogen of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River, CA, USA. This parasite requires two hosts - a freshwater polychaete (Manayunkia speciosa) and a salmonid - to complete its life cycle. The complex life cycle and large geographic area...
Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific lamprey enter freshwater and reside for ~ 1 year before spawning. This long exposure to the freshwater environment may affect...
Nanophyetus salmincola is a well-studied parasite of their definitive mammal hosts. However, the conditions that signal the time for shedding of N. salmincola cercariae from their first host, the juga snail (Juga silicula), is not fully understood. A digenetic trematode indigenous to the American Pacific Northwest, N. salmincola can be...
Phenotypic similarities of coho salmon (Oncorhynchus kisutch)
stocks from Oregon, Washington, and California were compared using
agglomerative and divisive cluster analyses. The phenotypic characters
evaluated included the following: 1) the isozyme gene frequencies
of transferrin and phosphoglucose isomerase; 2) the life history
characters time of peak spawning and proportion of...
As juvenile salmon migrate from freshwater into saltwater, physiological changes must occur to allow fish to osmoregulate in the marine environment. Juvenile spring Chinook salmon migrate to the ocean at different time periods, most notably in the fall (August – November; i.e. fall smolts) and spring (February – May; i.e....
More than 1500 species of plants and animals in the United States are listed as threatened or endangered under the Endangered Species Act (ESA). The U.S. Departments of Interior and Commerce are required, under Section 4(f)(1) of the ESA, to develop recovery plans for ESA-listed species under the respective agency...
The extensive reduction in adult Pacific lamprey (Entosphenus tridentatus) counts at many hydroelectric dams in the northwestern USA signals a substantial decline in lamprey numbers across the entire region in the past 40 to 50 years. Among the many potential causes of this decline, obstruction of migration routes has likely...