Abstract
Artificial structure has been used in the United States since the 1930s to modify benthic habitats in freshwater systems in attempts to enhance both sport and commercial fisheries. Since then, the use of artificial structure has become widespread throughout the country in a variety of waters and fish communities. Proposed advantages of installing artificial structure include increasing angler catch per effort, providing cover to increase survival of juvenile fish, and providing spawning habitat to increase natural production. Structure materials vary from brush piles and evergreen trees, to tires, hay bales, and manufactured plastic forms. The most effective types of artificial structure resemble natural structure with varied complexity and interstitial spaces. The success of structure projects is dependent upon the type of fish community present, the slope and depth at which the structure is placed, the amount and size of structure installed, and the type of structure that will best meet the goals of the project. The most successful structure projects are those which are implemented with clearly defined management goals. Those goals can only be formulated after an assessment of the fish community and the existing structure, and it has been determined that the addition of more structure will have a positive impact.
Acknowledgments
We would like to thank the following Washington Department of Fish and Wildlife staff for their numerous reviews and expert comments which made this a better document: Ray Buckley, Jim Scott, Paul Mongillo, Jim Uehara, and Steve Jackson.