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, October 14, 2010

The Big Island of Hawai‘i

by Darla White
The windward coast of the Big Island is very rugged and beautiful, with steep cliffs and characteristically rough waters. Access to these areas is quite limited, and human populations along the coast are sparse. The Main Hawaiian Island Reef Assessment and Monitoring Program (RAMP) expedition got off to a great start, with nice weather and favorable ocean conditions along the windward shore of North Kohala. The five small boats launched on their first day with views of Pololū Valley under blue skies and light winds. Of course, that did not last long; the winds picked up, and after a couple of days rains moved in, and the swell increased. However the diving was still good, albeit a bit murky at a couple of sites.

Waters off North Kohala, on the northeast coast of the island of Hawai’i. NOAA Photo by B. Vargas-Ángel

The opportunity to dive in these remote areas is uncommon, so I would like to share with you a little about what we do and what we have seen on our dives from the perspective of the Benthic Rapid Ecological Assessment (REA) Team. Benthos is the life that inhabits the sea floor, effectively attached to it, whether sessile (attached) or mobile (moving) on it, such as corals, mobile invertebrates, and algae. The Benthic REA team has a pair of divers for each of these three categories. Bernardo and Jake are the coral team, recording coral species and colony sizes and diseases. Molly and Max are the mobile invertebrate team, and they count critters and also work with the ARMS (Autonomous Reef Monitoring Structures; which Max is going to tell you more about soon).
Divers conducting belt transect surveys on the North Kohala Coast of Big Island. NOAA Photo D. White

Rodney is the limu (algae) expert, and he and I are the Line-Point-Intercept (LPI) team; whereby the organism (usually algae or coral) falling underneath the transect line is recorded to species level at every 20cm interval for 25 meters on each of two transect tapes. Photoquads (photographic images of the benthos) are also collected along the transect line. These methods combined gives a good ‘snapshot’ of the benthic community composition at this place and time. Everything out there has a role to play in this complex ecosystem, and looking at community composition can give you the pulse of an area. Our teams return to monitor the same locations year after year, and so will record changes over time.
Species of hard coral, encrusting sponges, and other sessile invertebrates populate the shallow benthos along the east coast of the Island of Hawaii. NOAA Photo D. White

Each of our sites is in depths of 45’ – 60’, too deep for pounding waves, but these areas observe plenty of water motion from surge and currents in these windward waters. Many of the sites that we surveyed were boulder habitats, where fields of boulders were encrusted with all kinds of life: hard corals, rubber corals, algae, sponges, urchins, and a variety of other critters about. It’s a veritable wall of mouths of a variety of shapes, sizes, and colors. The closer you look, the more you see…in fact, it is truly amazing just how much life is out there!

Close-up of sponge. NOAA Photo. D. White

When you are on the benthic team, you tend to have your head down most of the time and really don’t see many fish, apart from saddle back wrasses (Thalassoma duperrey) and the Hawaiian toby (Canthagaster jactator), and a few eels hiding out in the cracks. Loving fish like I do, I have made it a point to look around when I’m finished collecting data to see what I might find, and other times a buddy will point something out that I’m missing. I have a number of favorite fish, and so far I have not been disappointed. On the first day a couple of large kahala (Seriola dumerili) swam close to me as just happened to finish my data collection. The next day two reticulated butterflyfish (Chaetodon reticulatus) swam straight up to my mask as I fumbled for my camera. You know that you are in a remote area when the fish come to check you out instead of swimming away! Okay, the flame angel (Centropyge loricula) was a little shy…but that’s typical. At one site a manta ray (Manta birostris) glided around and around a swirling column of ‘opelu (Decapterus macarellus) 30’ high, which could only be topped by the two longnose hawk fish (Oxycirrhites typus) perched in the branches of a black coral. And, I think we’ve seen spinner dolphins every day thus far.

Longnose hawk fish (Oxycirrhites typus) perched on the branches of a black coral. NOAA Photo N. Pomeroy

We have spent the last couple of days on the leeward side of the Big Island and wow! The coral reef communities over here are truly amazing; I really wish my camera could do it justice. I’ll try to get some better pictures for you at South Point tomorrow!

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