Improving Coho Salmon Habitat in the West Fork of McGarvey Creek

Project Objectives: This project component will provide funds to continue: 1) Increase

juvenile Coho Salmon rearing capacity; 2) Increase beaver presence/abundance; 3) Increase conifer riparian vegetation; and 4) Control reed canary grass



Project Description: 1) Increase juvenile Coho Salmon rearing capacity by maintaining three BDAs in West Fork McGarvey Creek. Within the Final Recovery Plan for the Southern Oregon/Northern California Coast Evolutionarily Significant Unit of Coho Salmon (recovery plan) is the statement “The primary limiting habitat types for the Lower Klamath River (LKR) population are high quality spawning and rearing habitat”. To increase juvenile Coho salmon rearing habitat three series of Beaver Dam Analogues (BDAs) have been installed in the West Fork of McGarvey Creek. The habitat created by these structures has been monitored primarily through the use of Passive Integrated Transponder (PIT) tagging technology. The monitoring results show as good or better juvenile Coho salmon survival and growth within the BDA habitat compared to other high-quality rearing habitats within McGarvey Creek and other Lower Klamath tributaries. Many PIT tagged juveniles from other portions of McGarvey Creek and other tributaries of the Klamath River have been detected overwintering in the habitat created by the BDAs. However, these structures need periodic maintenance due to damage sustained during high winter flows. Maintaining the BDAs are related to the action steps in the recovery plan: SONCC-LKR.2.1.1 Increase channel complexity and SONCC-LKR.2.2.2 Reconnect the channel to the floodplain.

2) Increase beaver presence/abundance. Another objective for installing the BDAs is to increase beaver presence/abundance in the West Fork of McGarvey Creek. During the past several years beaver have built upon and expanded water storage capacity of the BDAs. In addition, they have added natural dams within the area. Several willow plantings have occurred in areas adjacent to the BDAs but they have been quickly consumed by beaver. In fact, most of the previous plantings have been consumed by beaver. The consumption rate of willow by beaver during previous plantings was underestimated and a greater number are needed to maintain a food source for beaver. The requested funds will used to restock 500 willow and increase beaver presence/abundance and revegetate riparian areas in the West Fork. The willow planting activities are related to the action steps in the recovery plan: SONCC-LKR.2.2.61 Increase beaver abundance and SONCC-LKR.7.1.16 Revegetate riparian areas.

3) Increase conifer riparian vegetation. Within the Final SONNC Coho Recovery Plan on page 18-17 is the passage “Degraded riparian forest conditions are a high stress for all life stages of Coho salmon in this population. Past timber harvest practices have resulted in the removal of nearly all mature conifers from tributary riparian areas (Gale and Randolph 2000). Riparian forests of LKR tributaries have not recovered from these activities, and in many cases, succession from deciduous (e.g., red alder) dominated riparian stands to conifer dominated forests is not occurring.” Although the West Fork of McGarvey Creek has been planted with conifers in the past the forest is still dominated by red alder in the riparian corridor. No plantings have occurred within the past 15 years. Recent observations have identified several areas within the West Fork riparian zone that are suitable for planting conifers that were missed in previous efforts. The proposed effort would stock 100 redwood and 100 spruce trees within the West Fork riparian zone. Conifer planting is related to the action step in the recovery plan SONCC-LKR.7.1.14 Increase conifer riparian vegetation.

4) Control reed canary grass. The lowermost series of BDAs in the West Fork of McGarvey Creek has areas where reed canary grass has become established. An experiment was conducted d

Project Benefit: 1) Benefits of maintaining the BDA structures include: increased floodplain connectivity, slow water habitat, pool depth, and habitat complexity that benefits both natal and non-natal juvenile Coho salmon.

2) Increased food for beaver, increased canopy cover to shade out reed canary grass, provide stream over-head cover for juvenile Coho salmon, increased food sources for insects that in-turn provide juvenile Coho salmon food sources.

3) Increased shading of reed canary grass and additional food sources for beaver. Beaver have been observed feeding on both redwood and spruce trees in the West Fork of McGarvey Creek. Increased stocking would also supplement losses of trees from beaver using them as food sources. Eventually these plantings would provide large woody debris sources for instream benefits related to increased channel complexity.

4) During decomposition reed canary grass removes dissolved oxygen from water. Removing biomass reduces oxygen demand especially during the summer. Reducing reed canary grass increases access to juvenile Coho salmon rearing habitat. Removal of reed canary grass allows for native plants to become established and grow. Once reed grass becomes fully established it creates a monoculture where native plants do not grow. Reducing reed canary grass increases native plant foraging opportunities for beaver.