The North Pacific Ocean is highly productive, hosting many of the world's largest groundfish populations and supporting a thriving fishing industry. Numerous regulations have been implemented to control the incidental take of non-target bycatch. Individual and Pooled Bycatch Quotas have recently been proposed as instruments that could further encourage the avoidance of such bycatch and increase enforceability of bycatch caps at less-than-entire-fishery levels of operation. The recent advent of fishing cooperatives such as the Pacific Whiting Conservation Cooperative and the Pollock Conservation Cooperatives create an additional impetus for examining the characteristics of pool and vessel specific bycatch quotas. We have constructed an object-oriented, hierarchical simulation that allows us to aggregate hauls of individual fish, up to single vessels, vessel pools, fleets (pools of vessel pools), and the entire fishery. This simulator is written in the object-oriented programming language, Java. It provides the flexibility to examine various sampling techniques and strategies and allows us to follow the precision of incidental catch estimates at various levels of operation. In particular, we examine the tradeoffs between the precision of bycatch estimates and consider management costs as observer coverage and pool size are varied. Bycatch arises from the use of harvesting technologies that imperfectly discriminate between target and non-target fish stocks. Even with a homogenous fishing fleet and without significant biological interactions, joint harvesting of multiple species poses problems for managers. For example, consider a fishery where two stocks are harvested in fixed proportions. Because population parameters vary across species, it is unlikely that optimal exploitation of one stock would simultaneously result in optimal catches of the other. To achieve optimal catches of the first stock, it would probably be necessary to accept suboptimal (low or high) harvests of the second. When fishers differ in their preferences for the two species, managers must trade-off benefits to the first sector against losses to the second. Similar problems arise even when there are no technological interactions if there are direct or indirect trophic interactions. Actual fisheries include both types of interaction. Consequently, it is difficult to predict the ecological or bioeconomic consequences of changes in target and incidental catch limits. Although elimination of bycatch may be uneconomical or even infeasible, the volume and composition of bycatch can be controlled indirectly through characteristics of the harvest gear, towing depth and speed, as well the time, season, and location fished. That is, bycatch is in part avoidable. For example, vessels operating during the CDQ (Community Development Quota) pollock (Theragra chalcogramma) fishery attain higher product recovery rates and lower bycatch rates than they attain while participating in the