Managing fish predators and competitors: Deciding when intervention iseffective and appropriate

摘要

Fisheries management agencies increasingly are being asked to weigh tradeoffs between game, nongame, native, and nonnative species management. Oregon recently has been considering a variety of interspecific intervention activities aimed at protecting and rebuilding depleted native fishes or improving native game fish production by managing potential predators and competitors. Activities range from reduced harvest restrictions on fish predators and competitors to more aggressive removal programs. Chemical treatment and predator hazing also have been considered for potential benefits to more desirable fish populations. This paper describes a systematic decision-making process to determine for any given case if: (1) predation or competition is likely to be important, (2) potential predators or competitors can be affected by changes in harvest or other management actions, and (3) biological benefits outweigh costs and social/political considerations. This process is applied to several of Oregon's problems to help identify examples where intervention might prove effective and appropriate.