Movement and habitat preference of California roach (Lavinia symmetricus), Sacramento sucker (Castotomus occidentalis) and three-spined stickleback (Gasterosteus aculeatus) in Strawberry Creek, California

Organisms migrate for a variety of reasons, often related to identifying habitat patches of higher quality. High quality patches often contribute to their growth, survival and reproduction. The goals of our study are to determine (1) movement patterns and (2) habitat preference of fishes at different periods of their life history. Our study system, Strawberry Creek, is a Mediterranean-climate stream that runs through the University of California, Berkeley. To study movement, we captured and implanted California roach (Lavinia symmetricus) and Sacramento sucker (Castotomus occidentalis) with uniquely coded passive integrated transponder (PIT) tags and tracked their location biweekly with a portable PIT antenna. Three-spined stickleback (Gasterosteus aculeatus) were too small to be tagged, but we estimated their abundance in different habitat types by capturing them with a seine every month. We characterized the physical conditions in each of our habitat units by measuring pool surface area, undercut size, and sediment size. We tested habitat preference by using a multivariate regression model that included the aforementioned physical factors as predictor variables. Preliminary data suggest that fish in Strawberry can move upstream and downstream but encounter some physical barriers that limit longer fish movements upstream. Restoration project on Strawberry Creek have attempted to introduce our study species into the North Fork of Strawberry Creek but have had little success because little is known about suitable fish habitat; this study can help guide future restoration attempts that aim to successfully introduce fishes into areas of Strawberry Creek that are currently devoid of fish.