Because of current federal laws on endangered fish species, water exports to California Aqueducts in San Joaquin Valley and Southern California are restricted by a combination of low Delta Smelt counts and densities in the Bay Delta and judgments by experts. This seminar suggests some ways in which Bayes’ Factors and combinations of forests of Information Odds Scores can help us improve our design of models that analyze large volumes of messy data, develop insights and better understand the major (“causal”) factors that are relevant in predicting future growths or declines in the species. Many different agencies, objectives and prior beliefs are involved.