Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Approaches to nonsalmonid small fish passage in arid areas of the American Intermountain West and Great Plains (#93)

William J Rice 1
  1. US Fish and Wildlife Service, Lakewood, CO, United States

The American Intermountain West and Great Plains host a myriad of native fish species, many of which are typically less than 50 mm in length and have developed in slow, low sloped, sandy stream environments. While little is known about various species passage performance, what is known is that many species are poor jumpers and swimmers, which complicate providing fish passage where slopes higher than 1% are desired. In addition, what may work for one species may not work for others due to behavioral differences. Various ramp fishways, embedded culverts and small bridges have all been used to facilitate passage, some working better than others depending on the environment with generally more success the more nature-like they are. Current design criteria and approaches will be discussed, case studies presented, data gaps and areas of needed research highlighted. As these little researched, nonsalmonid species populations diminish, understanding what we know and need to know to improve connectivity will become increasingly necessary to sustain them.