Design and Evaluation of Nature-Like Fishways for Passage of Northeastern Diadromous Fishes Final Report

Several nature-like fishway designs have been constructed in the northeastern US, but none of these fishways have been quantitatively evaluated for passage of northeastern diadromous species. This report summarizes data on passage performance from two studies of nature-like fishway designs for passage of river herring in the field (Town Brook, Plymouth, Massachusetts, and East River, Guilford, Connecticut), and from two years of tests of generic nature-like fishway designs (perturbation boulder and rock weir) in a semi-controlled laboratory environment. The field studies focused on passage of anadromous alewife (Alosa pseudoharengus); laboratory studies tested American shad (A. sapidissima), blueback herring (A. aestivalis), white sucker (Catostomus commersoni), white perch (Morone americana), striped bass (M. saxatilis), and smaller numbers of other nonanadromous riverine species. Nature-like fishways tested ranged in overall slope from 1:20 (laboratory and Town Brook site) to 1:15 (East River site).