Assessment of a retrofitted downstream fish bypass system for wild Atlantic salmon (Salmo salar) smolts and kelts at a hydroelectric facility on the Exploits River, Newfoundland, Canada

Abstract

In 2002 and 2003, the Bishops Falls hydroelectric generating facility on the Exploits River, insular Newfoundland, Canada, underwent extensive refurbishing including replacement of turbines and installation of a 'retrofitted' bypass and fish handling system. The effectiveness of this new bypass system has been assessed during the annual downstream run of wild Atlantic salmon smolt and kelt in smolt were radio tagged and released between June 9 and July 2, in the forebay of the hydro plant (19 releases) and one upstream (in-river) release. Fish guidance efficiency (FGE) of the system overall was 63% (123 of 195 fish) with 36 fish passing through the turbines, and six known mortalities. In 2004, between June 9 and July 2, a total of 358 smolt and 103 kelt were released in the forebay in 45 and 13 releases (n = 8 per release), respectively. The FGE of the system for smolt was 71.7% (257 of 358 fish) and for kelt was 92.3% (95 of 103 fish). In 2004, 96 tagged smolt passed through the turbines and 43 (44.8%) were detected at a downstream station confirming they had survived turbine passage, suggesting an overall survival of smolt passage of the Bishops Falls hydro facility in the order of 85%. A total of seven kelts (6.8%) passed through the turbines and were not detected 1.5 km downstream suggesting they did not survive turbine passage. Smolt spent on average 39.8 h in the forebay before exiting in 2003 and forebay residency averaged 26 h in 2004. In both years, most smolt selected their passage route, actively or passively, within the first 10 h with secondary peaks at 25-30 and 50-55 h, corresponding to evening passage in the second and third night, after release. Few smolt were bypassed or entrained into turbines during daylight hours. In both years turbine passed smolt spent more time in the forebay suggesting the longer fish reside in the forebay the greater the likelihood of turbine entrainment. Kelt were either bypassed or turbine entrained relatively quickly, within 2 h of release, and virtually all kelts were bypassed/turbine entrained during the hours of 18:00 and 01:00. These data on fish behavior and residency in the forebay will assist further refinement of operations of the bypass facility to optimize survival.

Migration and swimming depth of Atlantic salmon kelts Salmo salar in coastal zone and marine habitats

“…No diel control was apparent. The pattern of diel control on kelt seaward migration had been less consistent throughout the literature (Bendall et al 2005 andScruton et al 2007 identifying nocturnal migration; Östergren & Rivinoja 2008 identifying daytime migration). We hypothesize that the lack of a tendency for nocturnal migration is suggestive of low predation pressure on the kelts from piscivorous fish and birds: avoidance of predation should cause a preference for movement under the cover of darkness (Bendall et al 2005).…”

“…Some authors have identified kelt migration as being nocturnal (Bendall et al 2005 for sea trout Salmo trutta kelts), while Östergren & Rivinoja (2008) found that sea trout migration tended to occur during daytime. In the case of Atlantic salmon kelts, Scruton et al (2007) reported nocturnal migration, whereas no diurnal patterns were observed by Hubley et al (2008). Bendall et al (2005) found that sea trout migration tends to occur on the ebb tide.…”

Surgically Implanted JSATS Micro-Acoustic Transmitters Effects on Juvenile Chinook Salmon and Steelhead Tag Expulsion and Survival, 2010

“…Telemetry applications for fish range from monitoring fine spatial movements and habitat preferences to monitoring large-scale migratory patterns (Skalski 1998;Scruton et al 2007). Within rivers and basins, telemetry has proven to be an essential tool for assessing fish survival and movement patterns (Jepsen et al 1998;Skalski 1998;Plumb et al 2006).…”

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2010

“…Telemetry applications for fish range from monitoring fine spatial movements and habitat preferences to monitoring large-scale migratory patterns (Skalski 1998;Scruton et al 2007). In the Columbia River, scientists have identified acoustic telemetry as being an essential technology for observing the behavior and estimating the survival of juvenile salmonids passing through the side channels and the main-stem FCRPS (Faber et al 2001;McComas et al 2005;Ploskey et al 2007Ploskey et al , 2008Clemens et al 2009).…”