Goal:  The goal of this project is to guide kokanee away from a third powerplant penstock at Grand Coulee Dam, Washington using high intensity strobe lights.

Background: The construction of Grand Coulee and Chief Joseph dams completely blocked the passage of anadromous fish runs to the upper reaches of the Columbia drainage.  The impounded fishery is now dependant upon resident fish species that include kokanee and rainbow trout.  Each of the two species is adfluvial, migrating to tributary locations along Lake Roosevelt and Rufus Woods where they become accessible to tribal members and other sport fishers.  Studies conducted on Lake Roosevelt fisheries by the Spokane Tribe of Indians and Eastern Washington University indicated that substantial fish entrainment through Grand Coulee Dam may be occurring.
Entrainment has been documented at Grand Coulee Dam since 1996 and was found to be dependent upon such factors as annual water regimes, reservoir drafts, and upriver net pen and hatchery release strategies (LeCaire, 1999).  In addition, creel census surveys conducted on Lake Roosevelt by the Lake Roosevelt Fisheries Evaluation Program has documented reduced angler success despite increased hatchery out-planting (Cichosz et. al. 1996).  Further evidence of entrainment came from the collection of Lake Roosevelt kokanee at the Rock Island Dam bypass trapping facility and the collection of several hundred Floy-tagged rainbow trout at the same location (BioSonics, 2000). Entrainment was documented by the recovery of coded wire tags from Lake Roosevelt kokanee during an avian predator study on Rice Island, at the mouth of the Columbia River. (Mary Beth Tilson, Personal Communication, 1999).

There are several hypotheses on how fish use flow as a cue during downstream movements that may infer entrainment into large hydroelectric dams.  One hypothesis, although simplistic, is that fish follow the bulk flow.  Another hypothesis that has recently received more attention is that fish use turbulence (Coutant 1998) and acceleration fields (Haro et al. 1998) to sense passage routes.  The forebay of the Third powerplant of Grand Coulee is characterized by high flow as well as complex current patterns suggesting that turbulence and acceleration fields may also play a role in the entrainment of fish at Grand Coulee Dam.   Therefore, it is important to understand the water velocity and flow patterns in the forebay to plan strobe light deployment and evaluate entrainment patterns.  Initial surveys to describe flow patterns were undertaken in summer 2000 within the forebay region of the third powerhouse and across the entrance to the third powerhouse forebay (McMichael et al. 2000).

Diel changes in fish distribution may cause fish to be more vulnerable to entrainment at some times of the day.  Inasmuch as the third powerhouse is operated to meet power peaking needs, the diel changes may be an important factor. Causal mechanisms that induce shifts in salmonid diel vertical distribution have been attributed to food resource availability and feeding behavior (Groot and Margolis 1991), feeding opportunities and predation risk (Clark and Levy 1988), and underwater illumination (Narver 1970).  These studies were conducted on non-migrant juvenile sockeye salmon and should be generally applicable to kokanee in Lake Roosevelt and the forebay of Grand Coulee Dam.  
Behavioral Responses to Strobe Lights.

Constant light, strobe light, sound, and electricity have been used in the past by fishery biologists and managers to concentrate, redistribute, or guide fish (Sager et al. 1987, McIninch and Hocutt 1987, Nemeth and Anderson 1992). These behavioral technologies are becoming noteworthy as cost effective alternatives or supplements to physical barriers such as screens and nets.  The use of strobe lights as a behavioral barrier is based on the premise that when strategically placed underwater, they will evoke a negative stimulus, causing the fish to move away from the light.  Strobe lights, under this premise, have been considered as a potential means to reduce entrainment of fish at turbine intakes and other high mortality areas at hydroelectric facilities.  A suggested solution to limit entrainment of fish at third powerhouse was to divert them using an array of high intensity strobe lights.  We are proposing tools to test the efficacy of high intensity strobe lights when implemented at the entrance to the 3rd Powerplant forebay at Grand Coulee Dam for fish diversion.  
Although the use of strobe lighting as an effective behavioral guidance technology is in the early stages of development, some promising results have been observed.  Several evaluations have been conducted on the effectiveness of strobe lights in eliciting an avoidance response by fish.  Most studies have focused on salmonids. A typical strobe light deterrent system consists of a bank of flash heads emitting extremely rapid, brief, and brilliant flashes of light.  Flash heads can be operated at variable rates (300-450 flashes/min.) and intensities (400 + Watts).  The response of wild, free-ranging kokanee to strobe lights was tested in 1997 by the Idaho Department of Fish and Game.  Kokanee were found to move an average of 30 to 136 m away from the strobe lights in waters with Secchi transparencies from 2.8 to 17.5 m (Maiolie et al. 2001).  Wild Chinook salmon smolts were consistently repelled up to 6.25 m during cage testing of strobe lights during night at Roza Dam, Washington (Amaral et al., 2001).  However, during daytime testing, the smolts did not react to the strobe lights.  Yearling coho and sub-yearling chinook and coho smolts were consistently displaced both vertically and horizontally by strobe lights during net pen testing conducted by the U.S. Army Corps of Engineers near the Hiram M. Chittenden Locks, Washington in 1997 (Ploskey et al., 1998; Johnson et al., 2000a).  These results show promise for the concept of using strobe lights as a behavioral barrier.  However, these tests were conducted either in open water or in net pens, in the absence of any structure.  In order to adequately evaluate strobe lighting as a means to reduce fish entrainment at turbine intakes or guide fish to bypass structures, testing must be conducted near those structures.
  
The USGS evaluated the effectiveness of strobe lights in deterring steelhead smolts away from turbine induction slots at Cowlitz Falls Dam in 1999.  The results are currently being analyzed, but when complete should provide useful information with respect to the effectiveness of strobe lighting near structures.  A strobe light fish deterrent system was tested at Milliken Station's cooling water intake in Cayuga Lake, New York in 1995 and 1996.  All life stages of alewife, yellow perch, trout, perch, and white sucker were repelled consistently by the strobe lights during three seasons, but alewife, yellow perch, and white sucker were attracted during the fall (Stafford-Glase et al., Not Published).
Light, especially strobe light, is an effective stimulus to which juvenile salmonids and other fishes are known to respond.  However, the type of response (avoidance or attraction) may depend on factors such as: species and life stage of targeted fish, seasonal variation, diel patterns, and presence or absence of structure.  For example, at the fry stage walleye are positively phototactic at ambient light levels, but by the second year of life walleye exhibit a negative phototactic response (Ryder 1977).  These factors should be considered when attempting to identify candidate sites and applications for strobe lighting.

2001-2004 Strobe Light Studies at Grand Coulee Dam
Several factors affecting our evaluation have become evident in the past three years (2001-2004) (Simmons et al. 2002, Johnson et al. 2003, Simmons et al. 2004 and Johnson et al. 2005).  First, due to the relatively low densities encountered in the region of our study, it has not been apparent when the hatchery fish arrive at the study site.  In 2002, we moved our sampling period forward to capture earlier fish, but discovered the fish were arriving later than in 2001.  In 2003, we also noted fish arriving in large numbers during the last half of July.  In 2004, we instituted a later start (mid-June) and continued to the study to the middle of August to capture late arriving fish.  The results of these studies have concluded that fish are attracted to the vicinity of the strobe lights at night, but their behavior is altered to include rapidly swimming away from the lighted region orthogonal to the direction of the lights.  This may be a stress related behavior or a behavior associated with illuminated prey.  Other researchers have witnessed this type of behavior in kokanee when using pulsed light to capture free ranging kokanee for laboratory experiments (personal communication with Dr. Kim Hyatt, Department of Fisheries and Oceans, Canada).  It's the altered behavior that may prove advantageous to deter kokanee from entering the third powerplant penstocks at Grand Coulee Dam.

This year we have defined our objectives to support the deployment of strobe lights on one penstock for evaluation.  Conjunctively we will monitor the entrainment losses at the two adjacent penstocks on either side of the lighted test penstock using splitbeam hydroacoustics.  The project objectives are:

1. Conduct a hydroacoustic evaluation of fish entrainment and fish behavior relative to strobe lights mounted on one of the third powerplant penstocks.  This is the core project objective.

2. Conduct a hydroacoustic evaluation of fish entrainment and behavior on two adjacent unlighted penstocks.  This objective will provide additional information on fish deterrence adjacent to the strobe-lighted penstock.

3. Determine species composition of free ranging kokanee entering the third powerplant forebay in the region of the 2001-2004 studies.  This objective will provide species composition data relative to the passage estimates determined from hydroacoustic sampling and a posteriori evidence of species from earlier hydroacoustic sampling.
4. Examine the potential for enhancing natural spawning production along the shoreline of Lake Roosevelt.  This objective will largely be a literature search and design consultation in support of the Chief Joseph Kokanee Enhancement Project under which the strobe light evaluation falls.

Location of Project:  The project will be conducted at Grand Coulee Dam Third Powerplant forebay.  Grand Coulee Dam is located in the Upper Columbia sub-basin of the Inter-Mountain Province.

BPA-Furnished Property or Services:  No BPA-furnished property or services will be used on this project.