Effects of an increase in large wood on abundance and survival of juvenile salmonids (Oncorhynchus spp.) in an Oregon coastal stream

Authors: Johnson, Steven L.; Rodgers, Jeffrey D.; Solazzi, Mario F.; Nickelson, Thomas E.

Source: Canadian Journal of Fisheries and Aquatic Sciences, Volume 62, Number 2, 1 February 2005, pp. 412-424(13)

Publisher: NRC Research Press

Abstract:

We examined the effect of an increase in large wood on the summer population size, smolt abundance, and freshwater survival of steelhead (Oncorhynchus mykiss), coastal cutthroat trout (Oncorhynchus clarki clarki), and coho salmon (Oncorhynchus kisutch). We examined these parameters for five brood years prior to the addition of wood and five brood years after in Tenmile Creek, a direct ocean tributary on the Oregon coast. Over the same time frame, a nearby reference stream, Cummins Creek, was also sampled for the same parameters. The input of large wood into Tenmile Creek resulted from a planned habitat restoration project in 1996 and an unplanned addition of wood from a winter storm the same year. Steelhead smolt abundance, steelhead freshwater survival, and coho salmon freshwater survival increased in Tenmile Creek after the input of large wood. Steelhead age-0+ summer populations and steelhead smolt populations increased in the reference stream, although steelhead freshwater survival did not. Coho salmon populations remained unchanged in the reference stream. Our results illustrate the potential shortcomings of the before-after-control-impact study design under field conditions and the potential for misinterpreting results had we employed a more modest sampling plan.

Rise to the Future

The "Rise to the Future" awards are presented each year by the U. S. Department of Agriculture Forest Service to acknowledge top performers nationwide who are making significant contributions to aquatic resource management.

Recently the 2004 awards were announced and the Tenmile and Cummins Creeks Watershed Restoration Evaluation Project has been honored in the monitoring category.

The project was recognized for its demonstration of significant accomplishment in this category. The project consisted of monitoring the movement of large wood placed in the streams during restoration activities, as well as measuring the fish response to the addition of large wood.

"Restoration activities in the Cummins and Tenmile Creeks area are an example of an integrated effort to enhance a free-flowing coastal river by restoring ecological processes", stated Siuslaw National Forest Fisheries Biologist Jack Sleeper. "Monitoring the results and benefits of this restoration effort has been ongoing for over a decade".

Sleeper has the lead for monitoring the movement of large wood and has shared the monitoring results in the field with land owners, at Watershed Council meetings, at the Oregon Chapter American Fisheries Society meeting, and the Society for Ecological Restoration International Symposium in Victoria, B.C. August 2004.

The fish response to the addition of large wood was studied by Steve Johnson, Oregon Department of Fish and Wildlife. Paul Engelmeyer, with the Tenmile Audubon Sanctuary has been an instrumental part of restoration monitoring and sharing results.

One of the unique aspects of this monitoring project is the 10-year fish response monitoring using Cummins Creek as a control. Over-winter survival of coho and steelhead significantly increased in Tenmile Creek since large wood was added either through the project or natural occurance, while the no-treatment control basin remained unchanged. Steelhead smolt production doubled since large wood was added (project and natural) to Tenmile Creek.

Partners in the basin wide restoration project include the following:

· Tenmile Creek Landowners
· Tenmile Creek Association
· National Audubon Society
· Oregon Department of Fish and Wildlife-Research
· Oregon Department of Fish and Wildlife-Management
· U.S. Fish and Wildlife Service
· Siuslaw National Forest
· Trust for Public Lands
· Mid-Coast Watersheds Council
· Yachats Area Watersheds Council
· Angel Job Corps - Forest Service
· Oregon Youth Conservation Corps
· Region 6 Regional Office - Forest Service
· PNW Research - Forest Service
· National Aquatic Monitoring Center- Forest Service
· Lane County Road Department
· Jobs in the Woods-Salem
· Hire the Fisher-Newport
· Rocky Mountain Elk Foundation
· Pine Tree Conservation Society
· Trout Unlimited
· Boy Scouts-Lincoln City
· Georgia Pacific
· Volunteers