The corals of Wake

A Better Understanding of Coral Reef Ecosystems

Pelagic predators such as these barracuda, Sphyraena qenie, are part of the coral reef ecosystem in the U.S. Line Islands (NOAA Photo by Kevin Lino).

A team of scientists have embarked from Hawai'i on a three-month survey of coral reef ecosystems at Johnston Atoll, the U.S. Phoenix Islands, the islands of American Samoa, and the U.S. Line Islands in the tropical Pacific Ocean. The overarching objective is to better understand the coral reef ecosystems of these areas, many of which are seldom explored. The research expedition is part of a regular monitoring program, conducted by the Coral Reef Ecosystem Division (CRED), headquartered in Honolulu, Hawai'i. The expedition is supported by NOAA's Coral Reef Conservation Program and involves extensive cooperation among NOAA scientists and research partners, including the University of Hawaii Joint Institute for Marine and Atmospheric Research (JIMAR), the U.S. Fish and Wildlife Service, San Diego State University, and the Papahānaumaokuākea Marine National Monument.

The research expedition will be carried out from February 27 to May 24, 2012 aboard the NOAA ship Hi'ialakai. Under the leadership of Chief Scientists Dr. Jill Zamzow, Dr. Bernardo Vargas-Angél, and Jamison Gove, a diverse team of researchers will be conducting multidisciplinary coral reef ecosystem surveys, assessing the status of fishes, corals, algae, marine invertebrates, and the oceanographic conditions in which these organisms exist. The scientific data collected during the three-month research expedition will enable informed and effective implementation of ecosystem-based management and conservation strategies for coral reef ecosystems, helping to ensure their protection for generations to come.

Thursday, March 26, 2009

The corals of Wake

The coral reefs around Wake Island differ slightly from reefs surrounding the Hawai'ian Islands. The forereef and patch reef habitats typical around Oahu are on a wide shallow shelf which extends from shore.

Although the reef structures around Wake Island are also forereef and patch reefs (plus a large lagoon in the middle of the island), the shelf is more narrow and quickly drops to form very steep walls. Spur and groove formations and large coral bommies are typical on the south shore where there is less wave energy.

Coral diversity is also a little different between Wake Island and Oahu. In 2008, CRED found only 8 genera of corals during surveys in the waters of Oahu where three genera dominate: Porites (lobe coral), Montipora (rice coral), and Pocillopora (cauliflower coral).

Montipora colonies typically have either an encrusting or mounding morphology. It is often called rice coral because colonies often have prominent verrucae (thin calcium carbonate projections) giving the surface a bumpy appearance.

Members of the genus Pocillopora are usually branching forms with a yellow to brown color (above), but may also be bright purple (below).

The genus, Sinularia (cabbage leather coral; below), is one of the most common soft corals (also known as octocorals) found in Hawai'i and at Wake Island.

This past week, scientists found 24 genera of corals at Wake Island! Colonies of Montipora and Pocillopora were common (as they are in Oahu), but we also encountered Favia (moon, pineapple, star, brain coral), a genus not common on Oahu.