Coral recruitment in blasted and unblasted sites in Indonesia: assessing rehabilitation potential

Widespread blast fishing destroys living scleractinian corals and creates vast fields of shattered coral rubble that can only recover to coral dominance through a successional process that includes coral recruitment. Given the extent of damaged areas on many SE Asian reefs, successful recruitment and survival of juvenile corals will be important components of either natural recovery or human-assisted rehabilitation, Early scleractinian coral recruitment to tiles was assessed in blasted and unblasted sites in Komodo National Park, Indonesia, from 1998 to 2000. A total of 6530 corals recruited to 527 tiles (each 400 cm(2)), primarily of the families Acroporidae (27.1%), Pocilloporidae (44.7%) and Poritidae (12%). Acroporids settled primarily during NW monsoon months (October-April), while pocilloporids and poritids settled year-round. Standardized recruitment rates averaged from 285 to 772 spat m(-2) yr(-1) across all sites, with a site maximum of 2663 spat m(-2) yr(-1). While significant spatial and temporal variation was detected across sites and seasons, no significant difference in abundance of coral spat was found between blasted and unblasted sites. Results from this study suggest that these blasted sites are not recruitment-limited, and that failure of corals to recover in rubble fields is due to post-settlement mortality.