Session A8: Passage of Redband Trout at Irrigation Diversion Dams in the Donner Und Blitzen River, Oregon
Location
Groningen, The Netherlands
Event Website
http://fishpassage.umass.edu/
Start Date
24-6-2015 2:00 PM
End Date
24-6-2015 2:15 PM
Description
Abstract:
We evaluated passage delays of migratory redband trout (Oncorhynchus mykiss gairdneri) at three diversion dams on the Donner und Blitzen River, Oregon. Two of these dams have Denil fish ladders and the third one has a jump-pool ladder. Our study objectives were: 1) to compare redband trout delays among the three dams, 2) to determine whether trout experienced greater passage delay in entering the fish ladders or in ascending after the initial entry, and 3) to identify relationships between passage likelihood and water temperature, discharge, daylight, and fish fork length. An array of Passive Interrogation Transponder (PIT) antennas detected tagged trout, first, when they approached each dam, subsequently when they entered its ladder, and finally when they reached the upper end of that ladder. Therefore, data on ladder entry time, ladder ascending time, and total passage time for individual trout were obtained. Statistical methods for survival analysis were used because they handled both censored data and time-dependent covariates. The results showed that trout were 7 times more likely to pass the jumppool ladder during the day than during the night, but none of the other parameters were significantly associated with the likelihood of passage. Trout passage varied significantly between each of the dams. The expected median passage time was 0.07 days at one of the Denil fish ladders, 2.1 days at the jump-pool ladder, and 20.4 days at the other Denil ladder. At all three passage installations, a greater proportion of the total passage time involved ladder entry than ladder ascending. Entry time ranged from 14.6 to 71.5 times longer than ascending time among the three ladders. Our results revealed highly variable passage likelihood and time depending on ladder design, location and attraction flows.
Session A8: Passage of Redband Trout at Irrigation Diversion Dams in the Donner Und Blitzen River, Oregon
Groningen, The Netherlands
Abstract:
We evaluated passage delays of migratory redband trout (Oncorhynchus mykiss gairdneri) at three diversion dams on the Donner und Blitzen River, Oregon. Two of these dams have Denil fish ladders and the third one has a jump-pool ladder. Our study objectives were: 1) to compare redband trout delays among the three dams, 2) to determine whether trout experienced greater passage delay in entering the fish ladders or in ascending after the initial entry, and 3) to identify relationships between passage likelihood and water temperature, discharge, daylight, and fish fork length. An array of Passive Interrogation Transponder (PIT) antennas detected tagged trout, first, when they approached each dam, subsequently when they entered its ladder, and finally when they reached the upper end of that ladder. Therefore, data on ladder entry time, ladder ascending time, and total passage time for individual trout were obtained. Statistical methods for survival analysis were used because they handled both censored data and time-dependent covariates. The results showed that trout were 7 times more likely to pass the jumppool ladder during the day than during the night, but none of the other parameters were significantly associated with the likelihood of passage. Trout passage varied significantly between each of the dams. The expected median passage time was 0.07 days at one of the Denil fish ladders, 2.1 days at the jump-pool ladder, and 20.4 days at the other Denil ladder. At all three passage installations, a greater proportion of the total passage time involved ladder entry than ladder ascending. Entry time ranged from 14.6 to 71.5 times longer than ascending time among the three ladders. Our results revealed highly variable passage likelihood and time depending on ladder design, location and attraction flows.
https://scholarworks.umass.edu/fishpassage_conference/2015/June24/64
Comments
Presenting Author: Dr. Guillermo Giannico is an Associate Professor and Extension Fisheries Specialist in the Department of Fisheries and Wildlife at Oregon State University, Oregon. He has been conducting research on salmonid ecology and freshwater habitat utilization for over 20 years. In his role as Extension Fisheries Specialist, Dr. Giannico provides information, educational material, training courses and technical assistance to personnel from government agencies, watershed councils, NGOs, fishers, foresters, farmers and the general public on topics such as fish and aquatic ecology, land use impacts on freshwater systems and watershed restoration and planning.