Abstract
Attraction water for fishways is typically introduced through a diffuser inside the entrance channel, often through the floor or wall. In the spring of 2019, this laboratory study examined how 151 adult American Shad (Alosa sapidissima) responded to different gross velocities through a wall diffuser inside a full-scale fishway entrance channel. Two velocity conditions were studied, 0.152 m/s and 0.305 m/s, both without turning vanes inside the auxiliary water channel. The fish were tracked using the passive integrated transponder telemetry technique. The results of the experiments showed no difference in American Shad behavior when exhibited to the low and high velocity treatments. Moreover, shad passed the diffuser in roughly 3 out of every 4 attempts, regardless of the treatment. However, the similarity in shad behavior and passage performance is believed to be more of a result of the similarity in flow fields that resulted from the lack of flow guidance devices inside the auxiliary water channel. These findings therefore highlight the importance of properly maintained flow guidance devices, an often-overlooked component of an auxiliary water system.
Acknowledgements
The authors wish to thank current and former USGS employees John Noreika, Stephen Walk, Samuel Parker and Kevin Molongoski for their assistance with the shad collection, construction, data collection, video review, antenna construction, and more. Without their help, this work would not have been possible. Thank you to Alexander Haro for a thorough review of this manuscript. We also thank Holyoke Gas and Electric for access to their site and assistance with the shad collection. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The scientific results and conclusions, as well as any views or opinions expressed herein, are those of the author(s) and do not necessarily reflect the views of the U.S. Fish and Wildlife Service, NOAA, or the Department of Commerce. Data supporting the conclusions can be obtained through the U.S. Geological Survey ScienceBase-Catalog (https://www.sciencebase.gov/catalog/item/63937474d34e0de3a1efe158) following publication of this article in a peer-reviewed journal.
Disclosure statement
No conflict of interest has been reported by the authors.