Research Technical Report

Distribution of the Blackeye Goby, Rhinogobiops nicholsi, Around Temperate Reefs Along the Central Coast of California

Kelly, M. (May 2010)

A Capstone Project at California State University, Monterey Bay, 28pp.

ABSTRACT

A clear understanding of how species interact with each other as well as their habitat is necessary for successful management of marine ecosystems. Rhinogobiops nicholsi is an abundant, small, prey species that frequents the sand/rock interface along the edge of temperate reefs from southern Alaska to Baja, and is ideal for a habitat interaction study. To quantify the extent to which the blackeye goby utilizes this sand/rock ecotone, video transects collected by a towed camera sled in 2007 and 2008 were analyzed for the presence of blackeye gobies and their spatial relationship to temperate reefs. Data were collected at several locations within the Monterey Bay National Marine Sanctuary including: Soquel/North Monterey Bay, Point Lobos, Point Sur and Piedras Blancas. A pair of 10 cm sizing lasers were used to calculate the distance between individual gobies and the nearest hard substrate. A mean distance of 0.40 m from hard substrate was calculated, indicating that the utilization of this ecotone is critical for this species. During the data analysis, a green color morph was observed, which is distinctively different than the typical beige. This color morph is hypothesized to be associated with substrate, with green individuals occurring over rock and beige over sand. Corresponding with this, there was also a statistical difference in the distance that the two colors were observed from hard substrate: green 0.14 m and beige 0.44 m. This study has enhanced the knowledge about how blackeye gobies are distributed throughout their habitat, as well as provided baseline information on the ecotones surrounding temperate rocky reefs.