Skip to main content
U.S. flag

An official website of the United States government

Recruitment dynamics of non-native largemouth bass within the Sacramento-San Joaquin delta

December 20, 2020
Largemouth bass (LMB; Micropterus salmoides) recruitment is limited by a critical developmental period during early life stages, but this mechanism may be less important within non-native habitats. We conducted boat electrofishing surveys in four tidal lakes of California’s Sacramento–San Joaquin Delta (SSJD) from 2010 to 2011 to describe introduced LMB recruitment dynamics. We evaluated growth, proximate composition, and health indices of young-of-the-year (YOY) LMB among tidal lakes and developed an integrated count model to determine how factors known to affect LMB recruitment shape SSJD population structure. Our results show a mismatch among growth, nutrition, and YOY abundance, where the tidal lake with the most abundant and fastest-growing LMB had the poorest nutritional status. The warm winter water temperatures and lack of a hatching-cohort growth advantage suggests overwinter starvation plays a less important role in SSJD LMB recruitment than in many native LMB habitats. Collectively, our results suggest that habitat characteristics (submerged aquatic vegetation) and not overwinter mortality shapes SSJD LMB population structure, a mechanism consistent with contemporary hypotheses about the altered fish community structure of the SSJD.
Publication Year 2021
Title Recruitment dynamics of non-native largemouth bass within the Sacramento-San Joaquin delta
DOI 10.1139/cjfas-2020-0241
Authors Brock Huntsman, Frederick V. Feyrer, Matthew J. Young, James A. Hobbs, Shawn Acuna, Joseph E. Kirsch, Brian Mahardja, Swee Teh
Publication Type Article
Publication Subtype Journal Article
Series Title Canadian Journal of Fisheries and Aquatic Sciences
Index ID 70220277
Record Source USGS Publications Warehouse
USGS Organization California Water Science Center