Determining species distributions accurately is crucial to developing conservation and management strategies for imperiled species, but a challenging task for small populations. We evaluated the efficacy of environmental DNA (eDNA) analysis for improving detection and thus potentially refining the known distribution of Chinook salmon (Oncorhynchus tshawytscha) in the Methow and Okanogan Subbasi...

We estimated the impact of striped bass (Morone saxatilis) pre­ dation on winter-run chinook salmon (Oncorhynchus tshawytscha) with a Bayesian population dynamics model using striped bass and winter-run chinook salmon population abundance data. Winter-run chinook salmon ex­ tinction and recovery probabilities under different future striped bass abundance levels were estimated by simulating from...

Seasonal stock-specific distribution and abundance of Chinook salmon (Oncorhynchus tshawytscha) were determined using scale pattern analysis of Bering-Aleutian Salmon International Survey (BASIS) samples and catch data collected in the western Bering Sea in summer 2003 and fall 2002–2004. Chinook salmon were sparsely distributed in this region, which greatly limited the number of samples availa...

Olfactory epithelial structure and olfactory bulb neurophysiological responses were measured in chinook salmon and rainbow trout in response to 25 to 300 mg copper (Cu)/L. Using confocal laser scanning microscopy, the number of olfactory receptors was significantly reduced in chinook salmon exposed to $50 mg Cu/L and in rainbow trout exposed to $200 mg Cu/L for 1 h. The number of receptors was ...

We examined 1454 juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), captured in nearshore waters off the coasts of Washington and Oregon (USA) from 1999 to 2004 for infection by Renibacterium salmoninarum, Nanophyetus salmincola Chapin and skin metacercariae. The prevalence and intensities for each of these infections were established for both yearling and subyearling Chinook salmon. ...

Non-indigenous species may be the most severe environmental threat the world now faces. Fishes, in particular, have been intentionally introduced worldwide and have commonly caused the local extinction of native fish. Despite their importance, the impact of introduced fishes on threatened populations of Pacific salmon has never been systemically examined. Here, we take advantage of several uniq...

I compared diets of prickly sculpin, Cottus asper, and juvenile fall-run chinook salmon, Oncorhynchus tshawytscha, in the lower Mokelumne River, California, from January through June during 1998 and 1999. Prickly sculpin fed primarily on chironomid (Diptera) larvae and hydroptilid and hydropsychid (Trichoptera) larvae. Juvenile chinook salmon fed on zooplankton, plus chironomid, hydroptilid, an...

Five granitic rocks, concentrically disposed from core to rim, were distinguished in the Castelo Branco pluton. U-Pb-Th electron microprobe monazite ages from granitic rocks are similar and ranging between 297-303 Ma. The granitic rocks from Castelo Branco pluton are 310 ± 1 Ma old, obtained by U-Pb (ID-TIMS) in separated zircon and monazite crystals, indicating a similar emplacement age for al...

Anthropogenic effects on watersheds are important in explaining the decline of Pacific Northwest salmon stocks. Associations were tested between thirteen anthropogenic variables in 202 watersheds in Washington, Oregon, Idaho and California and the stock status of summer, spring and fall Chinook Onchorhynchus tshawytsha, coho O. kisutch, and winter steelhead O. mykiss. Summer Chinook had the hig...