Dynamics of endangered sucker populations in Clear Lake Reservoir, California

First posted May 18, 2021 For additional information, contact: Director, Western Fisheries Research CenterU.S. Geological Survey6505 NE 65th StreetSeattle, Washington 98115-5016 In collaboration with the Bureau of Reclamation, U.S. Survey began a consistent monitoring program for endangered Lost River suckers (Deltistes luxatus) and shortnose (Chasmistes brevirostris) in Clear Lake Reservoir, California, fall 2004. The was intended to improve understanding Reservoir populations because they are important recovery efforts these species. We report results from ongoing include sampling through 2019. summarize catches passive integrated transponder (PIT) tagging trammel net seasons (September–October each year) detections PIT-tagged on remote antennas spring year 2006 also combine data physical captures capture-recapture models provide estimates annual survival reservoir.A lack genetic distinctiveness between Klamath largescale (Catostomus snyderi) subbasin, including is likely cause past difficulty identification Field can be subjective many captured individuals, very few individuals were identified as most recent years our program. this report, we that either sucker (SNS) or (KLS) into single “SNS-KLS” group analyses. Identification (LRS) based external morphological characteristics.