Open Questions and Knowledge Deficits

Abstract

Almost 30 years ago, Pavlov (1989) summarized the state of the art from a contemporary point of view, with a positive outlook on the future. “Engineers have designed a large number of fish-protecting devices over the years […], and most reviews of fish protection provide descriptions of several of the structures used. However, most of the developmental work to date has been carried out by trial and error, and no structure yet satisfies the requirements completely. Empirical approaches to fish protection cannot define the precise conditions under which a given device will operate, nor the range of hydraulic and other parameters permissible for each device. In future, this should change as the design of fish-protecting devices will increasingly be based on biological knowledge so that the real ‘demands’ of the fish are met.