Recruitment of Pocillopora coral on experimental tiles in the Mexican Pacific

Abstract

Background. The recruitment of branching corals in the eastern Pacific is poorly understood despite being of paramount importance to the dynamics of coral populations. Experimental studies provide a non-destructive means to evaluate recruitment and compare settlement materials. Goals. To study Pocillopora recruitment on PVC and terracotta tiles in Bahía Ixtapa-Zihuatanejo (Mexican Pacific). Methods. We deployed 40 square (10 x 10 x 0.5 cm) experimental (20 PVC and 20 unglazed terracotta) tiles arranged as Calcification/Accretion Units at the Islote Zacatoso reef. Results. We observed two coral recruits at the edges of terracotta tiles, presumably due to light availability, and no recruits on horizontal sides, which may have been due to siltation stress, predation, or biofouling. No recruits were found on PVC tiles. Conclusions. Our findings indicate that the coral recruitment is low in the study area and that the terracotta tiles may be a better experimental substrate than PVC tiles to assess pocilloporid coral recruitment in the Mexican Pacific; however, further studies are needed to clarify this assumption.