In 1986 research divers surveyed and mapped deep-water spawning redds of fall chinook salmon (Oncorhynchus tshawytscha) in selected sites within an impounded segment of the main-stem Columbia River, Washington State, U.S.A. In velocities over 3 m sK1 and depths up to 11 m, two divers riding a manoeuvrable sled made cross-current transects communicating observations of substrate materials and deep-water spawning sites. Surface personnel tracked the position of the sled with a laser locating system that logged the information into data storage. Subsequently, the computerized data were translated into overlaying maps depicting location of redds, substrate materials, and depth contours.Deep-water spawning (>3 rn) occurred at most survey sites in velocities between 0.6 and 0.8 m s-'. The average depth of spawning was 6.5 m, and the maximum was 9-1 m-deeper than the depth redds can normally be detected by aerial observation ( 3 4 m ) . Deep-water spawning ranged from none to substantial in areas of near identical physical characteristics. A method for estimating abundance and density of deep-water redds, based upon the data collected with this mapping technique, is presented. This study combined with current limited information concerning deepwater spawning suggests that up to 80 per cent of the escapement of fall chinook salmon in this reach may spawn in deep water.KEY WORDS Fall chinook salmon Deep-water spawning River regulation Diver-sled Laser tracking and location

Several hydroelectric dams in the Snake-Columbia river system are equipped with submersible traveling screens that project into the turbine intakes. The screens are designed to divert juvenile migrant Pacific salmon Oncorhynchus spp. and steelhead Salmo gairdneri from the intake upward into gatewells and the ajoining central bypass system. Assays of gill Na+,K*-ATPase were performed on yearling chinook salmon O. tshawytscha collected during several routine fish guidance efficiency tests in 1985 and 1986. On three of the four sampling dates, gill Na*,K 4 -ATPase levels were significantly higher in fish guided into the gatewell than in those not guided. These data suggest there is a relationship between the physiological status of smelting yearling chinook salmon and their susceptibility to guidance by traveling screens. Assessments of salmonid out-migrations may be biased if they are based on samples from traveling-screen guidance systems.

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There are limited techniques available to assess the health of sea turtles as physical examination has little correlation to clinical findings, and blood reference intervals are broad and provide limited prognostic significance. Advances in the portability of ultrasound machines allow echocardiography to be increasingly used in the health assessments of wild animals. This study performed blood analysis and echocardiograms on 11 green sea turtles upon admission to a rehabilitation clinic and six animals before release. Significant differences were seen between groups, with admission animals having significantly smaller diameters of the cavum arteriosum at systole and diastole, smaller E‐waves and an increased fractional shortening. Pre‐release animals displayed significant increases in the maximum blood velocities of both the pulmonary artery and the left aorta. Significant negative correlations were seen between fractional shortening and uric acid and between the velocity time integral of the pulmonary artery and urea. The pulmonary artery velocity time integral was also significantly correlated to the E wave. Furthermore, there was asynchrony between the cavum arteriosum and the cavum pulmonale and the detection of a parasitic granuloma in the ventricular outflow tract of one animal. Overall, the results suggest that cardiac function in stranded green sea turtles is significantly impaired and that echocardiography has applications in the health assessments of green sea turtles.