Predicting response of migratory fish populations to dam removal

Dam removal is a potential habitat restoration alternative through which parties responsible for injuries to natural resources can provide compensation for reductions in fish populations. Predicting the potential response of migratory fish populations to candidate dam removal(s) is a critical step in the natural resource damage assessment process to evaluate whether the proposed action provides adequate compensation. There is currently no standard approach to making such predictions, particularly in cases where data on candidate streams with dams are limited. We considered six modeling approaches for addressing this problem and evaluated the features of each approach for this application. We judged that an approach based on habitat suitability indices and weighted usable area provides the best balance between predictive capacity and cost of model implementation. This balancing act evaluating the cost effectiveness of predictive models is worth consideration in a wide range of fisheries modeling applications.