PARENT SESSION
Contributed Oral Session 136: Fish Communities, Management, and Recruitment
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 518 C, Level 5, Palais des congrès de Montréal
Using Tier III Monitoring at Various Scales as a Planning Tool for Stream Restoration.
Giannico, Guillermo*,1, Heppell, Scott 1, Li, Hiram 2, Feldhaus, Joseph1, Madriñan, Luis1, Tattam, Ian1, 1 Department of Fisheries and Wildlife, Corvallis, Oregon, U.S.A.2 Oregon Cooperative Fisheries Research Unit (USGS-BRD), Corvallis, Oregon, U.S.A.
ABSTRACT- Remote images are efficient for sampling at large spatial scales, and patterns at these scales can indicate habitat conditions and limiting factors critical for stream restoration. However, these patterns are correlative and should be ground truthed to establish cause and effect (essentially Tier III stream monitoring according to the classification used by the Bonneville Power Administration in the Columbia River basin). Hypotheses concerning patterns are tested at different levels of biological organization that correspond to different spatial scales. Once causal mechanisms are identified the monitoring of other basins using remote images (Tier I monitoring to establish resource status) is simplified, because spurious correlations have been identified. We propose that it may prove advantageous to first conduct intensive Tier III monitoring, rather than last as suggested by its number (i.e., Tier I vs. III). This approach is being tested in the John Day basin (Oregon) with the hypothesis that steelhead (Oncorhynchus mykiss) production is greater in colder (18-22°C) rather than warmer (> 22°C) stream reaches during summer. We use longitudinal temperature patterns to identify habitat patches and classify them into categories of physiological tolerance. The location of PIT-tagged fishes is geo-referenced and fish are subsequently tracked over time to determine their habitat preferences and seasonal movements. Ideal Free Distribution theory is applied to explain the spatial distribution of individuals in response to habitat characteristics; and several metrics are used to predict smolt production, physiological influences on growth and survival, and PIT-tag detections at various fixed locations. Our preliminary results indicate that reach summer temperatures may not only control juvenile steelhead numbers (with more fish found in colder habitats) but also may influence the subsequent fall-spring fluvial migratory patterns.
Key words: Monitoring, Stream Restoration, Steelhead, Ideal Free Distribution