Lake Ozette Sockeye Population Monitoring

The project will contribute to salmon recovery by addressing specific goals, research needs, and monitoring identified in the Lake Ozette Sockeye HGMP (Makah 2000). The five main components are listed below:
A) Lake Ozette Sockeye Smolt Trapping (Ozette River)
B) Lake Ozette Sockeye Adult Run Size Estimation (Ozette River Weir)
C) Umbrella Ck. Adult Sockeye Escapement (Weir tagging/recovery)
D) Sockeye/kokanee spawner surveys/otolith and genetic sampling and analyses (Lake and Tributaries of the Ozette basin)
E) Juvenile sockeye marking (Umbrella Creek Hatchery and Makah National Fish Hatchery)


Task A) A preliminary ranking of research needs and suspected limiting factors by impacts on life stage was developed by the Lake Ozette Habitat Technical Work Group (HGMP Appendices A and B). Both identified smolt monitoring as the highest priority need, as did the Lake Ozette Sockeye Supplementation Technical Work Group. Annual smolt abundance estimates and trends in freshwater and marine productivity of hatchery- and natural-origin sockeye are critical needs to determine stock status, recovery goals, and effectiveness of hatchery supplementation activities


Lake Ozette Sockeye Smolt Trapping in the Ozette River will measure total smolt production in the Ozette basin for all salmonid species. These smolt abundance estimates are necessary to measure marine and freshwater survival and productivity (smolts per spawner), to measure the relative contributions of natural- and hatchery-origin sockeye to the total sockeye smolt yield, and to estimate post-release survival rates of hatchery-origin Lake Ozette sockeye smolts. All of these performance indicators are integral to evaluating and refining recovery efforts.


Task B) Adult sockeye run size entering Lake Ozette is monitored annually to estimate abundance and productivity. This is necessary for recovery of the Lake Ozette sockeye ESU. Detailed adult sockeye run size enumeration is conducted annually by Makah Fisheries Management using an underwater video camera on the Ozette River weir, operated 24 hours per day, excluding minor stoppages due to equipment failure or human error. Resulting abundance estimates for natural- and hatchery-origin adult sockeye are determined by reviewing camera images for adipose fin clip ratios (a known proportion of hatchery fingerling releases are adipose clipped) and subsequently compared to estimates from both the adult weir at Umbrella Creek and stream spawner surveys.


Computer software is used in conjunction with manual QC review methods to review fish passage and identify adipose clips and predation marks. The resulting estimates of survival to adult return are essential to monitor the status of this ESU. The methods utilized are resulting in increasingly accurate measurements of abundance for this ESU, and provide significant savings in technician hours and costs, enabling work on other elements of salmon recovery.


Task C) This task will monitor adult sockeye escapement to Umbrella Creek by enumerating the total run and its subcomponents (hatchery- and natural-origins). Adipose clips and otolith marks will be used to detect hatchery fish and identify their release groups. Adult upstream migrants will be externally tagged at a weir located at RM 1.0 in Umbrella Creek. Subsequent observation of the tag and clip ratios of spawned out carcasses recovered in foot surveys on the spawning grounds in Umbrella Creek will be used to calculate total escapement.


The resulting escapement estimate will be subtracted from the total run size measured entering the lake at the Ozette River weir (Task B) to derive the abundance of the listed lake spawning population (after computing additional natural holding and predation mortalities). The Lake Ozette Sockeye Steering Committee and an independent panel of fisheries experts identified this project as a critical monitoring compone

This project will allow Makah Fisheries Management to:

-determine the of number of adult sockeye entering Lake Ozette,

-determine the proportion of the runs of both outmigrating smolts and returning adults that are of hatchery origin,

-determine the relative proportions of tributary and beach spawning populations,

-evaluate the health and condition of the fish entering the lake,

-capture and tag adult sockeye salmon, both for broodstock collection and refinement of tributary spawner population estimates

-differentiate between hatchery rearing and release groups, which in turn facilitates evaluation of supplementation, rearing and release protocols.


All of these parameters are vital to the monitoring and evaluation of the status of the ESU listed Lake Ozette Sockeye and to the evaluation of performance and effectiveness of the various supplementation and recovery projects.