Thirty years of coral reef change in relation to coastal construction and increased sedimentation at Pelekane Bay, Hawai‘i

Stender Y, Jokiel P, Rodgers KS. 2014. Thirty years of coral reef change in relation to coastal construction and increased sedimentation at Pelekane Bay, Hawai‘i. PeerJ. 2:e300(DOI 10.7717/peerj.300):1-15

Abstract: Coral reefs are being critically impacted by anthropogenic processes throughout the world. Long termmonitoring is essential to the understanding of coral reef response to human impacts and the effectiveness of corrective management efforts. Here we reevaluated a valuable coral reef baseline established in Pelekane Bay, Hawai‘i during 1976 and subsequently resurveyed in 1996. During this time interval substantial impacts occurred followed by extensive corrective measures. Coral and fish communities showed dramatic declines from 1977 to 1996 due to massive harbor construction and suboptimal land management practices on the watershed. More recently, corrective measures in the form of watershed stabilization and fishing regulations have been implemented. Consequently our 2012 survey reveals that coral cover since 1996 has increased slightly accompanied by a significant increase in fish abundance, diversity, and evenness. This improvement can be attributed to lower fishing pressure since 1996 due to reduced shoreline access, tighter fishing regulations and increased monitoring of legal and illegal fishing activities. Stabilization of the coral community can be attributed partially to reduced sedimentation resulting from watershed restoration that included installation of sediment check dams, control of feral ungulates, controlled grazing and replanting of native vegetation. Insights into the mechanism that removes sediment from reefs was provided by a major storm event and a tsunami that remobilized and flushed out sediment deposits. The increase in herbivorous fishes probably played a role in reducing algal competition in favor of corals. The data suggest that the precipitous reef decline in this area has been arrested and offers support for the corrective actions previously undertaken.

Type
Journal Article
Authors
Stender, Yuko; Jokiel, Paul; Rodgers, Ku‘ulei
Units
PUHE
Keywords
Coral reefs, Hawai‘i, Land-based impacts, Long-term monitoring, Sedimentation
Subjects
Ecological Framework: Geology and Soils | Geomorphology | Marine Features and Processes , Ecological Framework: Water | Hydrology | Marine Hydrology , Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities

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