Application of Equivalent Adult, Equivalent-Recruit and Production Foregone Modeling in 316(b)122.21(r)(10)-(12) Studies

Given the important role that cost/benefit analyses will play in the determination of BTA for entrainment under the Final 316(b) Rule promulgated in August 2014, there will be renewed interest in the application of Equivalent Adult (EA), Equivalent-Recruit (ER) and Production Foregone models (PFM) developed and applied as part of the cost benefit analyses in prior 316(b) studies.  These techniques are of special interest in the evaluation of the benefits of entrainment reduction because seemingly very large numbers of eggs and larvae lost due to entrainment often translate, i.e., are equivalent via the EA and ER models, to relatively small losses to recreational and commercial fisheries.  The PFM provides a quantitative estimate of the forage biomass lost as a result of entrainment.

This presentation begins with a historical perspective discussing the evolution of the techniques and some examples of their prior applications.  With this historical perspective in mind, the common pitfalls in the application of the techniques are discussed and guidelines are provided for their application and interpretation in the context of their anticipated application in 316(b) studies that will be performed in response to §122.21(r)(10) to (12) of the Final 316(b) rule.