Examination of diver-operated video surveys as a method to monitor kelp forest communities
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Date
2024-01-10
Authors
Persad, Samantha
Journal Title
Journal ISSN
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Publisher
University of Oregon
Abstract
In the Northeast Pacific, some kelp forests are shifting to urchin barrens due to ocean-warming events, predator releases, and overgrazing by the purple sea urchin (Strongylocentrotus purpuratus). In regions like Southern Oregon where scuba surveys are limited by season and surge, ecological data are sparse. To calibrate a more efficient, accessible survey method, we performed invertebrate and algae swath surveys using simultaneous manual and video methods at historical kelp forest transects in Oregon. Our kelp forest sample size was too low to draw significant conclusions about survey methods in such habitats. In urchin barrens, the video method captured more urchins on average than the manual method, with more disparity as urchin densities increased. Sea stars in barrens were underestimated using the video method, which may be remedied by adapting the survey protocol. There was no significant observer variation when quantifying urchins from video surveys. There was little difference in the average time required to complete data collection and extraction between methods. The video method required far less time underwater, highlighting the benefit of the video method in areas where diving is opportunistic. This thesis includes unpublished co-authored material with the Oregon Department of Fish and Wildlife and the Oregon Coast Aquarium.
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Keywords
Ecology, Kelp forest, Marine, Monitoring, SCUBA, Survey