PMNM Divers Discover Table Coral Acropora cytherea off Oʻahu

Table Coral Acropora cytherea discovered off Oʻahu by PMNM Divers. Credit: Daniel Wagner/NOAA

During a routine proficiency dive off the south shore of Oʻahu last November, PMNM research divers came across an astounding find – the first record of the table coral Acropora cytherea from this island. This species has never before been recorded from Oʻahu, despite being the most accessible and heavily surveyed island in the Hawaiian Archipelago.

Given its common name due to its flat-topped, table-like shape, table corals (Acropora sp.) are the primary reef-building corals throughout most of the tropical Pacific, but have never been observed in waters off Oʻahu. In Hawaiʻi, the distribution of A. cytherea is largely limited to French Frigate Shoals and neighboring islands in the NWHI. There are only three previous published records of its presence in the Main Hawaiian Islands, none from Oʻahu.

Diver gets an estimate of the coral's size using a measuring stick. Credit: Daniel Wagner/NOAA

PMNM Research Diver Brian Hauk examines the newly-discovered table coral off Oʻahu. Credit: Daniel Wagner/NOAA

PMNM Research & Field Operations staff were diving with closed-circuit rebreathers, which allow for extended dive times and enable divers to survey very large areas, feats that are not possible using conventional SCUBA. The table coral, which is estimated to be 14 years old, was sighted toward the end of a three-hour long dive in 60 feet of water, signifying the importance of this technology for making such discoveries. Researchers also used this same technology while exploring deep reefs on a recent research expedition to Papahānaumokuākea and Johnston Atoll in June (read the story).

A report on the discovery was published in the Bulletin of Marine Science on June 28, 2013. The article, authored by PMNM staff members Randy Kosaki, Jason Leonard, Kelly Gleason, Brian Hauk and Daniel Wagner, can be accessed online at www.ingentaconnect.com/content/umrsmas/bullmar/pre-prints/8943 (a subscription fee may apply).

Read the Press Release.

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