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 11, 2010

Ofu & Olosega Islands

View of the south side of Ofu (left) and Olosega (right)
(Photograph by Kerry Grimshaw)
By Kerry Grimshaw

We are currently working near the islands of Ofu and Olosega, which are part of the Manu’a group of islands (which also includes Ta'u). They lie approximately 100 km northeast of Tutuila. Although geographically separate, these islands are often referred to together because they are only separated by a narrow straight (approximately 75 m) that is bridged by a shallow coral reef. The twin islands of Ofu (on the west), and Olosega (on the east) are formed by two sharply eroded, overlapping shield volcanoes which gives these islands a dramatic landscape.

Ofu and Olosega are inhabited with the majority of their population (approximately 500 people according to the 2000 census figures) living in the 2 main villages of Ofu and Olosega. An interesting fact I learned from the National Park of American Samoa’s website is that the To’aga archeological site near Ofu Beach has evidence of more than 3,000 years of continuous human occupancy and some modern descendants still live nearby in Ofu Village.

The south-coast beach of Ofu-Olosega with it’s the 4km (2.5mi) stretch of white sand is one of the most beautiful in the South Pacific. Much of the southern coast is also part of the National Park of American Samoa. Along this stretch there are excellent opportunities to snorkel and see some of the 300 species of fish and 150 species of coral that can be found there. Through our shallow water multibeam mapping in 2004 we learned that Ofu and Olosega had a previously uncharted bank top that is less than 300m deep and extends between 0.2 – 2km offshore before dropping to abyssal depths.

Our work this year will continue efforts to monitor fish, coral, algal, invertebrate, and microbial communities at depths ranging from 3 - 30m (10 - 100 feet) deep, as well as a suite of oceanographic observations to better understand the processes influencing these organisms. This data will be compared with that from the other islands we've visited to get an understanding of overall reef health of this area of the world.

1 comment:

  1. I have been following your voyage and just was informed of your blog reporting daily activities. It is fascinating and educational. I understand that there are SanDiego people on board, they may not know it but there is a JETS fan on board also. hope they are getting along. Frank M