PNNL

Abstract

This report documents an investigation into the performance of a novel fish-protection screen intended to prevent small aquatic and marine organisms from entering water intakes in free-flowing water bodies. The proposed prototype screen resembles conventional, slotted fish-protection screens with parallel wires or bars; however, the prototype bars are shaped to mimic the filter elements in the mouths of filter-feeding fishes such as the devil ray (Mobula tarapacana). Millions of years of evolution have perfected these structures to provide energetically efficient and clog-resistant filtering of zooplankton from seawater. The intent of the prototype is to exploit these mechanisms for the protection of similarly sized, or larger, organisms in settings where the freely flowing current is approximately parallel with the screen face (i.e., sweeping flow) and perpendicular to the screen bars.