An anchoring system for fish habitat structures: field technique, evaluation, and application.

Abstract

Steel cable can be used to bind rocks and logs together to construct fish habitat structures in streams. Cables must be securely anchored if structures are to withstand floods. This paper describes a way to anchor cables into bedrock or ballast boulders. Anchor tensile strength ranged from 7,500 to 36,500 pounds and was related to type of resin and embedment depth. After a major flood, we examined 127 instream structures that had been secured to rock with this technique; only 0.02 percent of the 300 individual anchor points had pulled out. The resin was toxic to rainbow trout {Salmo gairdneri) fry in bioassays, but exposure to the toxicant is minimal under field conditions.

Citation

Fontaine , Barbara L.; Merritt, Thomas D. 1988. An anchoring system for fish habitat structures: field technique, evaluation, and application. Res. Note. PNW-RN-481. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 12 p