MEPS 365:177-186 (2008)  -  DOI: https://doi.org/10.3354/meps07489

ABSTRACT: Although there are many studies of fauna associated with seagrass beds in sheltered embayments and estuaries, few have explored such associations in open coastal environments. We determined species richness and documented recruitment and the relative abundance of older life stages of conspicuous, non-cryptic fishes in subtidal surfgrass Phyllospadix torreyi beds in San Diego County, California, USA. Using underwater visual surveys, we explored the relationships between several habitat attributes and the densities of fishes. We then tested experimentally the effects of disturbance (removal of surfgrass) on the densities of fishes. Standardized to the number of individuals encountered, species richness increased with increasing bed area. Expectedly, the variables that explained variation in the density of fishes were species specific. After removal of surfgrass from one-half of the area of disturbed reefs, densities of recruits generally were significantly higher on the undisturbed versus disturbed halves of the reefs, while the densities of older life stages were unaffected. Recruitment in relation to surfgrass area revealed a significant interaction between unmanipulated and disturbed reefs, with a decreasing trend in density on unmanipulated reefs and an increasing trend on disturbed reefs. Our results indicate that surfgrass beds serve as an important habitat for near-shore fishes, and the loss of surfgrass from disturbance has negative consequences for recruitment success.

KEY WORDS: Fishes · Surfgrass · Disturbance · Habitat loss · Recruitment · Phyllospadix torreyi · Seagrass