Upper Extent of Fish
The distribution boundary at the upper extent of fish across
North America receives extra attention because stream reaches
with fish are managed differently and often have more protections
than fishless reaches. In western North America, Coastal
Cutthroat Trout (Oncorhynchus clarkii clarkii) are the fish
generally found the highest in their stream networks and are,
therefore, the central focus when considering the upper extent of
fish in streams.
|This work is an example of successful coproduction among partners, including USDA Forest Service, Bureau of Land Management, Oregon Department of Forestry, Weyerhaeuser Company, Hancock Forest Management, and Port Blakely.|
To understand more about the upper extent of fish, I am working with collaborators across landownerships to understand the relative reliability of various tools to determine the fish distribution boundary. We are using GIS and LiDAR tools, and well as comparing eDNA sampling to traditional electrofishing to inform managers and decision-makers.
In Penaluna et al. (2021), Coastal Cutthroat Trout eDNA was detected
Land managers can use eDNA to detect last-fish to inform forest management in addition to traditional tools. We suggest that as the discussion of eDNA as a management tool continues it is important to distinguish between the science of eDNA (e.g., methodological sensitivities, limitations) and the implications that are derived from its information (e.g., fish presence). As managers start to incorporate eDNA surveys to detect last-fish, they may want to use more than one criterion to define a positive eDNA detection as part of a decision-making framework. For example, a threshold of a positive eDNA detection could be set for a given number of replicates to separate a consistent series of strong detections from a few weak detections, as well as incorporating information about potential barriers to fish movement and other habitat characteristics (e.g., wetlands, habitat complexity).
See link to RTE Radio 1 (Ireland) radio feature:"Mooney Goes Wild, 1 February 2021." Penaluna section begins at minute 29 of the audio.
Penaluna B.E., J.M. Allen, T. Levi, I. Arismendi, T.S. Garcia, and J.K. Walter. 2021. Better boundaries: delimiting the upper fish distribution boundary of fish in forested streams with electrofishing and environmental DNA. Ecosphere 12(1):e03332. https://doi.org/10.1002/ecs2.3332 (open access)