Temporary Lamprey Passage and Video Monitoring

This Project was 100% funded by the California Fish Passage Forum and the Bureau of Indian Affairs Endangered Species Act Program.

The Tolowa Dee-ni' Nation Fisheries Program received funding in 2019 from the California Fish Passage Forum to install a temporary dvsh-xa~ min'-waa-'alh (lamprey passage) and video monitoring system at Tvm-chaa-dvn (Rowdy Creek Fish Hatchery). Currently, the Tvm-chaa-dvn weir prevents dvsh-xa~ from moving upstream on Rowdy Creek. In September of 2020, this temporary passage was installed to improve dvsh-xa~ access to upper Rowdy Creek, until full removal of the weir can occur. The weir removal process is underway with a feasibility study completed in 2014, design plans developed in 2018 and an environmental compliance in progress (expected to be complete by 2021). Upon completion of environmental compliance the Fisheries Program will seek funding for implementation of this critical restoration project, deemed the number one priority fish passage barrier in Del Norte County.

The dvsh-xa~ or the Pacific Lamprey is a native, anadromous fish that serves important ecological functions in the streams of the Pacific Coast. Larval dvsh-xa~ rear for 5-7 years in the fine sediments of streams, reaching approximately seven inches before migrating out to sea. During this time they are filter feeders, cleansing the water and mixing the bottom sediments by burrowing in stream beds. In-migrating adults serve as prey for many species- osprey, black bear, eagles, raccoons, otters, seals, sea lions, to name a few, providing a buffer that reduces predation on our lhuk (salmon) populations. Much like lhuk, dvsh-xa~ do not feed once they enter freshwater and die after spawning, releasing rich marine nutrients into freshwater streams. Unfortunately, dvsh-xa~ populations are declining all along the Pacific Coast, decreasing their beneficial impacts on our ecosystems and negatively impacting their availability as a nutritious, traditional food source for the Tolowa Dee-ni'. The design of this passage is very effective - from the initial entry on the drain channel, lampreys will enter a 4” tube and climb upstream through the video monitoring box, up to the exit. Each dvsh-xa~ passing through the tube will activate motion sensors and trigger the video recording, creating a short video while providing informative data including an image, body length, and overall population count/estimate of dvsh-xa~ that utilize the passage. The motion activated video reduces time and effort for staff, since only footage with dvsh-xa~ will need to be reviewed. There is a critical lack of monitoring for migrating dvsh-xa~ on the Pacific Coast, the improved passage at Rowdy Creek Hatchery will make a significant contribution to the conservation and management of dvsh-xa~ populations.