Klamath Tribes Ambodat staff working in a collaborative effort to monitor anadromous fish species

Numerous Tribal, state, federal, non-profit, and academic partners are working together to monitor anadromous fishes as they repopulate newly available habitats upstream of the former dams on the Klamath River. This collaborative effort follows the historic removal of four dams, which is expected to revitalize anadromous species that have been blocked from their traditional spawning grounds for over a century. The dams, which were removed as part of an agreement designed to restore river health and support the region’s Indigenous Tribes, blocked the migration of fish species such as Chinook salmon, Coho salmon, Pacific lamprey, and steelhead trout. On August 28, 2024, the last of four dams (Iron Gate) was breached on the Klamath River, a major milestone for recovering the river’s ecosystem.

The first adult fall Chinook salmon was observed migrating past the former Iron Gate dam location three days later via sonar imaging. On Oct. 16, Chinook salmon were observed in Spencer Creek, Oregon. Substantial numbers of Chinook salmon were observed spawning the following month in the mainstem Klamath River between the former dam locations and Keno dam, as well as multiple tributaries, including Jenny Creek, Shovel Creek, Fall Creek, and Spencer Creek.

The Klamath Tribes Ambodat department and the Oregon Department of Fish and Wildlife (ODFW) are spearheading monitoring efforts in Oregon. This collaborative partnership employs various monitoring strategies to characterize the upstream distribution, abundance, and life history characteristics of returning anadromous fishes. Specifically, monitoring strategies include utilizing radio telemetry and passive integrated transponders (PIT tags), conducting visual surveys, and collecting biological samples from post-spawn salmon carcasses. Moreover, 10,000 experimental spring Chinook salmon smolts are released annually in Upper Klamath Lake and tributaries to better understand habitat use as well as to identify passage or water quality barriers to outmigration. In the future, we will be implementing rotary screw traps (to estimate juvenile productivity), fish traps in the Link River fish ladder to radio and PIT tag adults (to understand individual movement and habitat use), and video weirs in Spencer Creek and the Link River fish ladder (to estimate run size). 

This Oregon monitoring effort has revealed substantial spawning by fall Chinook salmon in the mainstem Klamath River from the Oregon/California border to Keno Dam. Furthermore, substantial spawning is also occurring in Spencer Creek. In Oregon, the maximum daily counts of spawning fall Chinook are 176 in the mainstem Klamath River and 182 in Spencer Creek. Bureau of Reclamation (BOR) staff observed Chinook Salmon ascending the Keno fish ladder, and a monitoring camera at the Link River fish ladder recorded a few large unidentifiable salmonids (salmon or trout) ascending the structure, indicating salmon may have migrated into tributaries of Upper Klamath lake. These observations triggered the Upper Basin Salmon Monitoring Strategy, and thus far, over 55 kilometers of tributary habitats upstream of Upper Klamath Lake have been visually surveyed (via snorkeling and standup paddleboard floats), principally the Wood, Williamson, and Sprague Rivers. However, these survey efforts have yet to identify fall Chinook salmon upstream of Upper Klamath Lake.

The abundance of and speed at which fall Chinook repopulated habitats upstream of the former dams exceeded many expectations. Despite these early victories, significant work remains to be done as Coho salmon continue to be threatened under the Endangered Species Act and Spring Chinook populations are depleted, far downstream of the former dams. Fall Chinook are the most abundant salmon species and life history, spawning in appreciable numbers directly below the former Iron Gate dam. Thus, it is likely recovery will be slower in the Upper Basin for Coho and Spring Chinook salmon as they are more depleted and must stray farther to reach newly available habitat compared to fall Chinook.

Furthermore, there is growing concern that the fish ladders at the Keno and Link River dams are unsuitable for passage. In particular, attraction flows (river flows that help fish find the entrance to the fish ladder) are not suitable for migrating salmon at the Keno fish ladder, uncertainty exists around juvenile outmigration survival at Keno, and small trash rack gaps at the Link River and Keno fish ladder may prevent the largest salmon from entering Upper Klamath Lake. There is no evidence that large numbers of salmon are packing below Keno unable to ascend the fish ladder, but it is still critical the fish ladders enable easy passage for the river’s migrating fishes.  

The Klamath Tribes, ODFW, and BOR staff are working tirelessly to implement temporary solutions at the fish ladders to remedy any migration hurdles present for these culturally, commercially, and recreationally important fishes.  Moreover, The Klamath Tribes, National Oceanic and Atmospheric Administration, ODFW, BOR, and other partners will soon conduct a feasibility analysis of Keno’s fish ladder that will evaluate and identify long-term operational and structural solutions to improve passage.

Although fall Chinook salmon have responded favorably to dam removal, there remain challenges to long-term recovery in the Upper Basin. Pacific lamprey, coho salmon, Spring Chinook, and steelhead trout face the same challenges as fall Chinook but some of these species (Coho and Spring Chinook) are much more imperiled. Despite these challenges, The Klamath Tribes, ODFW, and numerous other partners remain committed to recovering anadromous species in the Upper Basin. The fast and robust response of fall Chinook to dam removal underscores the resolve of the 25+ year collaborative movement to restore the Klamath watershed and is encouraging for current and future efforts to restore self-sustaining, fishable populations of salmon, steelhead, and lamprey in Upper Klamath Lake and its tributaries.

Jordan Ortega is an anadromous fish specialist for the Klamath Tribes Ambodat Department.