Using spatial, seasonal, and diel drift patterns of larval Lost River suckers Deltistes luxatus (Cypriniformes: Catostomidae) and shortnose suckers Chasmistes brevirostris (Cypriniformes: Catostomidae) to help identify a site for a water withdrawal structure on the Williamson River, Oregon |
| |
Authors: | Craig M Ellsworth Torrey J Tyler and Scott P VanderKooi |
| |
Institution: | (1) U.S. Geological Survey, Western Fisheries Research Center, Klamath Falls Field Station, 2795 Anderson Avenue, Suite 106, Klamath Falls, OR 97603, USA;(2) Present address: U.S. Bureau of Reclamation, Mid-Pacific Region, Klamath Basin Area Office, 6600 Washburn Way, Klamath Falls, OR 97603, USA |
| |
Abstract: | A small irrigation diversion dam near Chiloquin, Oregon, was removed and replaced with a pump station to improve fish passage
for Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) entering the Sprague River on their spawning migrations. During the developmental phase of the pump station, a need was
identified to better understand the larval drift characteristics of these endangered catostomids in order to reduce entrainment
into the irrigation system. The spatial, seasonal, and diel distribution of drifting larvae was measured during the 2004 spawning
season at two proposed sites on the Williamson River where the pump station could be located. Larval drift for both species
coincided with the irrigation season making them subject to entrainment into the irrigation system. Drift occurred almost
exclusively at night with larvae entering the drift at sunset and exiting the drift at sunrise. Nighttime larval densities
were concentrated near the surface and at midchannel at both sites. Densities were generally greater on the side of mid-channel
with greater flow. During early morning sampling we detected a general shift in larval drift from surface to subsurface drift.
We also observed an increase in larval densities towards the shore opposite from the proposed pump station at the upper site
whereas larval densities remained high at midchannel at the lower site. During daytime sampling, the few larvae that were
collected were distributed throughout the water column at both pump sites. This study found that larvae drifting during all
time periods were generally distributed further across the cross section, deeper in the water column, and closer to where
the proposed water withdrawal structure would be built at the downstream site when compared to the upstream site. Recommendations
were provided to locate the withdrawal facility at the upstream site and operate it in a manner such that larval entrainment
would likely be minimized. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|