Lower Klamath River Tributary Juvenile Salmonid Assessment

This project consisted of monitoring salmonid smolt outmigration in Blue Creek a Lower Klamath Tributary in 2020-21. Crews operated a rotary screw trap in Blue Creek to estimate the number of smolts outmigrating during spring - fall. This project provided valuable information regarding annual trends in abundance of outmigrant salmonids from these Lower Klamath tributaries, assessing the overall status of the unique Lower Klamath late-fall run chinook and ESA listed Coho salmon, as well as steelhead and coastal cutthroat trout.

Project Benefits

Provide data so that management actions (timber harvest, road maintenance, restoration efforts, harvest management of late-run fall Chinook, etc.) can be improved with respect to their effect on anadromous fish in general, and particularly with respect to ESA-listed SONCC Coho Salmon and late-fall Chinook Salmon.

In McGarvey Creek, considerable restoration has addressed limiting factors to juvenile Coho production through introduction of large woody debris, engineered log jams, reforestation, and creation of off-channel habitat (alcoves). In addition, installation of beaver dam analogs occurred during the summer/fall 2018 and will address another limiting factor which is over-summer rearing habitat that remains watered throughout the summer months. Success of these projects will be assessed through the continuation of the long-term data set for estimates of juvenile Coho outmigrants at the McGarvey Creek Pipe Trap. The success of restoration in addressing limiting factors such as over-winter and over-summer rearing habitat will be assessed through the response of the juvenile Coho population through time. A positive response in the juvenile population over time will infer that restoration has been successful. Furthermore, we are currently conducting analysis of overwinter survival for PIT tagged McGarvey Creek juvenile coho from brood year 2009 forward to assess the effect of restoration on juvenile coho overwinter survival. An increase in overwinter survival over time will infer that creation of over-winter habitat through restoration has resulted in a positive population response. We have also started to measure over-summer survival beginning in the summer of 2015. Therefore, analysis of population and over-winter/over-summer survival estimate trends over time will be used to assess whether restoration actions have addressed limiting factors in the McGarvey Creek watershed. A positive response in population estimates and/or survival will be used as indicators that restoration actions have been successful. Our results will be communicated through a technical report.
Recent restoration actions in the Blue Creek watershed include tribal acquisition of large tracts of the Blue Creek watershed and upslope restoration activities. Over 15,000 acres have been designated as an old growth forest preserve. In addition, within the next couple of year’s considerable instream restoration through the introduction of large woody debris, engineered log jams, and flood plain connectivity will address limiting factors within the Blue Creek watershed. The Yurok Tribe exercises treaty fishing and subsistence rights on Blue Creek Chinook and the mentioned restoration actions are anticipated to benefit the population. Continuation of the long term monitoring of juvenile Chinook production at the Blue Creek rotary screw trap will help inform the success of these restoration actions. An increase in juvenile Chinook production over time will infer that restoration actions have been successful. In addition, we are currently analyzing the stock recruitment relationship between juvenile production and adult estimates to determine density dependent relationships within Blue Creek Chinook that may help inform upcoming instream restoration actions. An increase in recruits per spawner over time will infer that restoration actions have been successful. The stock-recruit relationship may also be used to create maximum sustained yield and harvest management decisions for the Blue Creek stock. Since the most significant restoration actions have not yet taken place in Blue Creek we will communicate what we have learned from the previous 20 years of monitoring about Blue Creek monitoring in a report including the stock- relationship. Our results will be communicated through a technical report.