Using 3D Acoustic Telemetry to Assess the Response of Resident Salmonids to Strobe Lights in Lake Roosevelt, Washington; Chief Joseph Kokanee Enhancement Feasibility Study, Annual Report 2001-2002.

Perry, Russlee ; Farley, M. ; Hansen, Gabriel

United States. Bonneville Power Administration.

关键词: Dimensions;    Shores;    Dams;    Acoustics;    Turbines;   

DOI  :  10.2172/963049
RP-ID  :  DOE/BP-00004767-1
RP-ID  :  4767
RP-ID  :  963049

美国|英语

来源: UNT Digital Library

【 摘 要 】

In 1995, the Chief Joseph Kokanee Enhancement Project was established to mitigate the loss of anadromous fish due to the construction of Chief Joseph and Grand Coulee dams. The objectives of the Chief Joseph Enhancement Project are to determine the status of resident kokanee (Oncorhynchus nerka) populations above Chief Joseph and Grand Coulee dams and to enhance kokanee and rainbow trout (Oncorhynchus mykiss) populations. Studies conducted at Grand Coulee Dam documented substantial entrainment of kokanee through turbines at the third powerhouse. In response to finding high entrainment at Grand Coulee Dam, the Independent Scientific Review Panel (ISRP) recommended investigating the use of strobe lights to repel fish from the forebay of the third powerhouse. Therefore, our study focused on the third powerhouse and how strobe lights affected fish behavior in this area. The primary objective of our study was to assess the behavioral response of kokanee and rainbow trout to strobe lights using 3D acoustic telemetry, which yields explicit spatial locations of fish in three dimensions. Our secondary objectives were to (1) use a 3D acoustic system to mobile track tagged fish in the forebay and upriver of Grand Coulee Dam and (2) determine the feasibility of detecting fish using a hydrophone mounted in the tailrace of the third powerhouse. Within the fixed hydrophone array located in the third powerhouse cul-de-sac, we detected 50 kokanee and 30 rainbow trout, accounting for 47% and 45% respectively, of the fish released. Kokanee had a median residence time of 0.20 h and rainbow trout had a median residence time of 1.07 h. We detected more kokanee in the array at night compared to the day, and we detected more rainbow trout during the day compared to the night. In general, kokanee and rainbow trout approached along the eastern shore and the relative frequency of kokanee and rainbow trout detections was highest along the eastern shoreline of the 3D array. However, because we released fish near the eastern shore, this approach pattern may have resulted from our release location. A high percentage of rainbow trout (60%) approached within 35 m of the eastern shore, while fewer kokanee (40%) approached within 35 m of the eastern shore and were more evenly distributed across the entrance to the third powerhouse cul-de-sac area. During each of the strobe light treatments there were very few fish detected within 25 m of the strobe lights. The spatial distribution of fish detections showed relatively few tagged fish swam through the center of the array where the strobe lights were located. We detected 11 kokanee and 12 rainbow trout within 25 m of the strobe lights, accounting for 10% and 18% respectively, of the fish released. Both species exhibited very short residence times within 25 m of the strobe lights No attraction or repulsion behavior was observed within 25 m of the strobe lights. Directional vectors of both kokanee and rainbow trout indicate that both species passed the strobe lights by moving in a downstream direction and slightly towards the third powerhouse. We statistically analyzed fish behavior during treatments using a randomization to compare the mean distance fish were detected from the strobe lights. We compared treatments separately for day and night and with the data constrained to three distances from the strobe light (< 85m, < 50 m, and < 25 m). For kokanee, the only significant randomization test (of 10 tests) occurred with kokanee during the day for the 3-On treatment constrained to within 85 m of the strobe lights, where kokanee were significantly further away from the strobe lights than during the Off treatment (randomization test, P < 0.004, Table 1.5). However, one other test had a low P-value (P = 0.064) where kokanee were closer to the lights during the 3-On treatment at night within 85 m of the strobe lights compared to the Off treatment. For rainbow trout, none of the 11 tests were significant, but one test had a low P-value (P = 0.04), and fish were further away from the strobe lights during the 6-On treatment, within 50 m, during the day (Table 1.5). During 2002, it is unclear whether tagged fish truly had little response to the strobe lights, or whether too few fish near the strobe lights and short residence times prevented us from detecting a behavioral response to the strobe lights. Although fish tended to be slightly further away from the strobe lights during 3-On and 6-On treatments compared to the Off treatment, only one of the 21 statistical tests indicated that these differences were significant. However, within 25 m of the strobe lights we may have had little power to detect a difference due to the few fish available for statistical comparison. We detected 32 kokanee and 7 rainbow trout in the tailrace of Grand Coulee Dam, accounting for 30% and 12%, respectively of the fish released.