Kenyon, J. C., Aeby, G. S., Brainard, R. E., Chojnacki, J. D., Dunlap, M. J., Wilkinson, C. B.

Mass coral bleaching on high-latitude reefs in the Hawaiian Archipelago

2006

Proceedings of the 10th International Coral Reef Symposium, Okinawa, Japan. June 28-July 2, 2004

2

631-643

"The first mass coral bleaching ever recorded in the remote Northwestern Hawaiian Islands (NWHI), a chain of small islands, atolls, and banks that span ~1800 kilometers over more than five degrees of latitude in the northern part of the Hawaiian Archipelago, was documented in late summer 2002. Between 9 September and 5 October 2002, towed-diver surveys covering more than 195 km of benthic habitat and belt-transect surveys at 118 sites were conducted at 10 banks and atolls in the NWHI and included assessment of coral bleaching across latitude, depth, zone, and taxon. Incidence of bleaching was quantified as percent cover of coral that was bleached from analysis of towed-diver survey videotapes, and as the percentage of colonies with bleached tissue from colonies counted within belt transects. Both methods indicated that the incidence of bleaching was greatest at the three highest-latitude atolls in the Hawaiian Archipelago (Pearl and Hermes, Midway, and Kure), with lesser incidences of bleaching on reefs at Lisianski and farther south in the NWHI. At the three northern atolls, bleaching was most severe on the backreef, moderate in the lagoon, and low on the deeper forereef. The average incidence of coral bleaching experienced in different geomorphic systems and zones closely corresponds to the composition of the dominant coral fauna coupled with its susceptibility to bleaching. Sea surface temperature (SST) data suggest that prolonged, elevated SST is a likely explanation for the bleaching response."

French Frigate Shoals, Maro, Laysan, Lisianski, Neva Shoal, Pearl and Hermes, Midway, and Kure, Northwestern Hawaiian Islands