Location

Construction & Engineering Hall, Oregon State University

Start Date

27-6-2013 10:05 AM

End Date

27-6-2013 10:25 AM

Description

Thousands of culverts across the western U.S. present passage barriers to inland trout, and as a result the U.S. Forest Service and other agencies have dedicated a great deal of money to remove or restore culverts to allow passage. Determining that fish are actually moving through restoration sites, however, is difficult, time-consuming and expensive and there is little direct evidence of fish passage to confirm the effectiveness of restoration. Genetic data may provide movement information with less effort than traditional methods (demographic, mark-recapture, telemetry), often at less expense. We contrasted a suite of genetic techniques to capture movement of cutthroat trout from different age classes over three remediated culverts: 1 in Idaho and 2 in adjacent tributaries in Montana. Genetic data prior to culvert removal and samples from unrestored neighboring sites allowed for before-after and ‘control’ comparisons in Montana. Heterozygosity was unchanged in the control and treatment sites in MT over the study period. Effective size decreased slightly while allelic richness was unchanged in the control population, but allelic richness increased significantly in both treatment sites 3 years after passage restoration. Individual assignment tests captured movement of age 1+ fish across restored culverts and sibship analyses, based on pedigree reconstruction of young-of-year fish and power-validated with simulated pedigrees, demonstrated movement across culverts even just shortly after emergence. Our results provide guidance on the efficacy of different genetic techniques to detect movement over short time-frames and small spatial scales.

Comments

Helen Neville As part of Trout Unlimited’s national science team, Helen works on a broad array of genetics topics ranging from the conservation genetics of important native fisheries, to characterizing non-native fish invasions and hybridization, to application of genetic tools to understanding fine-scale movement. She has a Ph.D. from the University of Nevada, Reno, a Masters degree from the University of California, San Diego, and a Biology degree from Brown University. Before coming to TU in 2006 Helen was a post-doc with the US Forest Service's Boise Aquatics Lab

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Jun 27th, 10:05 AM Jun 27th, 10:25 AM

Concurrent Sessions A: Passage Effectiveness Monitoring in Small Streams I - Genetic Evaluation of Cutthroat Trout Movement Through Remediated Culverts

Construction & Engineering Hall, Oregon State University

Thousands of culverts across the western U.S. present passage barriers to inland trout, and as a result the U.S. Forest Service and other agencies have dedicated a great deal of money to remove or restore culverts to allow passage. Determining that fish are actually moving through restoration sites, however, is difficult, time-consuming and expensive and there is little direct evidence of fish passage to confirm the effectiveness of restoration. Genetic data may provide movement information with less effort than traditional methods (demographic, mark-recapture, telemetry), often at less expense. We contrasted a suite of genetic techniques to capture movement of cutthroat trout from different age classes over three remediated culverts: 1 in Idaho and 2 in adjacent tributaries in Montana. Genetic data prior to culvert removal and samples from unrestored neighboring sites allowed for before-after and ‘control’ comparisons in Montana. Heterozygosity was unchanged in the control and treatment sites in MT over the study period. Effective size decreased slightly while allelic richness was unchanged in the control population, but allelic richness increased significantly in both treatment sites 3 years after passage restoration. Individual assignment tests captured movement of age 1+ fish across restored culverts and sibship analyses, based on pedigree reconstruction of young-of-year fish and power-validated with simulated pedigrees, demonstrated movement across culverts even just shortly after emergence. Our results provide guidance on the efficacy of different genetic techniques to detect movement over short time-frames and small spatial scales.