Acropora gemmifera encrusting form, photo courtesy DLNR

KAILUA-KONA, Hawaii – A research team diving in the waters off West Hawaii have found an unusual coral species never before documented near the Hawaiian Islands.

According to the Hawaii’s state Department of Land and Natural Resources, the coral has been identified as Acropora gemmifera, which is common in shallow, tropical reef environments in the Red Sea, Australia, the Indo-Pacific, and central and western Pacific.

The discovery was made by a team of divers working under the DLNR Division of Aquatic Resources divers, under the leadership of senior biologist Dr. Bill Walsh. The find was detailed in a DLNR media release issued on Wednesday.

While doing reconnaissance SCUBA dives along the Kona coast of the Island of Hawaii, the dive team came across a large number of coral colonies, which none of the researchers had ever seen before. These robust finger-like colonies didn’t even look like they were related to any other corals in the vicinity of the main islands.

After returning the next day and photographically documenting the colonies, the coral was tentatively identified as Acropora gemmifera. Not only is this the first record of Acropora gemmifera in the main Hawaiian Islands, it’s the first record of any Acropora species occurring around the island of Hawaii.

Visual identification of the coral was subsequently confirmed by genetic sequencing done by Narrissa Spies of the Richmond Lab at the Kewalo Marine Laboratory, Pacific Biomedical Research Center in Honolulu.

“The presence of these coral colonies is a significant contribution to our understanding of local reef diversity and opens up speculation about what other rare corals may be found on the reefs of Hawaii island,” Walsh said. Hawaii State DLNR media release, Jan. 29 2014

Large colony of Acropora gemmifera with white tumor (growth anomaly) just below center of image, photo courtesy DLNR

The Kona population is located in waters 4 to 10 meters deep, which is within its typical, intertidal and subtidal range of 1 to 15 meters. Although other colonies have been known to have a blue or purple color, the Kona colonies are a typical tan/brown color, “ranging from young encrusting forms to mature colonies estimated to be at least 80 years old.” 75 colonies have been counted at the Kona site along a 50-meter stretch of reef.

The DLNR says Acropora gemmifera does occur at Johnston Atoll, approximately 900 miles southwest of Hawaii. Other Acropora species have been identified in the Northwestern Hawaiian Islands; previously, several small colonies of the table coral Acropora cytherea have been reported from Kauai, and a single colony was recently sighted off Oahu. The state says there have been no historical reports of any Acropora species occurring around the Island of Hawaii nor were any observed in more than 4,500 DAR coral reef monitoring or research dives over the past 15 years.

Multiple colonies of Acropora gemmifera. Photos by DLNR Division of Aquatic Resources

According to the DLNR the discovery “emphasizes the need for local marine and land-use conservation practices.”

Members of this genus have a low resistance and low tolerance to bleaching and disease, which can be made worse by pollution, overfishing, and climate change. They are also a coral species preferred by Acanthaster planci, the crown-of-thorns starfish, which is a coral predator. Hawaii State DLNR media release, Jan. 29 2014