Evaluation of Infrasound and Strobe Lights to Elicit Avoidance Behavior in Juvenile Salmon and Char.

Abstract

The success of this project depended on the involvement and cooperation of many people. The project was managed by Ken Barnhart of the Bonneville Power Administration (BPA). We thank Jeff Condiotty and Frank Knudsen from Simrad Incorporated for their assistance in leasing the infrasound device and Ron Brown from Flash Technology for loaning the strobe lights. We also thank Pacific Northwest National Laboratory (PNNL) staff Fenton Khan, Jeff Marco, and Anita Muzak for their assistance in analysis of the videotapes.

Chief Joseph Kokanee Enhancement Project : Strobe Light Deterrent Efficacy Test and Fish Behavior Determination at Grond Coulee Dam Third Powerplant Forebay.

“…the response to lights include fish species. Strobe lights elicited an avoidance response in wild and hatchery Chinook salmon and rainbow trout but none in eastern brook trout (Mueller et al 2001). The target size of fish detected in this study puts them in the range for kokanee and rainbow trout released into Lake Roosevelt (Table 4.1 and Figure 4.1); however, we have no independent evidence that the fish were kokanee.…”

“…The response to light can be affected by factors such as turbidity (McIninch and Hocutt 1987) and fish age (Kwain and MacGrimmon 1969;Anderson et al 1988;Fernald 1988). Strong avoidance response has been noted for chinook salmon smolts during nighttime hours (Amaral et al 2001;Mueller et al 2001), while in another study the density of juvenile salmon was lower when lights were on during daylight (Johnson et al 2001). Juvenile rainbow trout (10 months) showed a preference for darkness when given the choice between light (0.01 lx) and darkness.…”

“…This is probably related to predator-prey relationships, where younger fish are more vulnerable to predation and so avoid the light, while older fish become the predator and thus are less likely to shun light. Fish not responding to lights include cutthroat trout fry and hatchery-reared trout (Brett and MacKinnon 1953) and eastern brook trout (Mueller et al 2001). Studies of kokanee exposed to strobe lights showed an immediate avoidance reaction to the lights, with a more pronounced response in winter when turbidity was reduced (Maiolie et al 2001).…”

“…More than 50% of the targets detected during the study were within the range calculated for kokanee and rainbow trout. Because response to lights can be dependent on fish species (Mueller et al 2001;McInich and Hocutt 1987) and on the age of the fish (Kwain and MacGrimmon 1969), and, thus, indirectly related to size, for the analysis we divided the data into three size categories: small (≤-42 dB), medium (>-42 to ≤-32 dB), and large (>-32 dB).…”

“…This may indicate that a change in species or age composition occurred within the detected population. A number of researchers have reported species-specific and age-specific responses to strobe lights (Hoar et al 1957;Mueller et al 2001;Kwain and MacGrimmon 1969). Thus, if the behavioral responses observed over the duration of the study came from different species or ages of fish, the effect of strobe lights on kokanee and rainbow trout may have been obscured.…”