Spatial variation in bottom epifauna in the Santa Maria Basin, California

Abstract

From the Abstract: “Hard-bottom epifauna were photographically sampled at 11 locations in the Santa Maria Basin near Platform Hidalgo. The sampling locations ranged in depth from 105 to 212 m, and were categorized as either low-relief (0.2-0.5 m) or high-relief (>1.0 m) habitat. Sampling was conducted on seven occasions between October 1986 and October 1990. Analysis of variance indicated that the 22 most common taxa varied according to depth and habitat relief with many taxa exhibiting highest abundances in deeper high-relief locations. Some of the deep high-relief taxa also varied according to orientation on high-relief rocks, and most often faced into stronger currents. Conversely, several taxa which were most abundant in low-relief habitat often faced into weaker currents. There was a strong negative correlation (r = -0.988) between the combined abundances of the deep high-relief taxa and the flux of suspended sediments measured with near-bottom sediment traps at each location. We suggest that the rich epifaunal assemblages that characterize deep high-relief habitat in the Santa Maria Basin are associated with a balance between the positive effects of high current speeds and the negative effects of suspended sediments.”