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.

Saturday, January 30, 2010

Fish Tales

by Kara Osada-D'Avella
For this first leg of the expedition, our fish team is made up entirely of women – but no fish about it, we are out to take on the seas and collect data no matter the conditions; sunny or rainy; rough or calm. Our team lead, Paula Ayotte, is on her third trip to these waters along with me (Kara Osada-D’Avella), Jonatha Giddens and Emily Donham. As reports of over-fishing worldwide have topped headlines, concern for the possibility of over-fishing occurring on coastal reefs has also been increasing. According to recent scientific reports, over-fishing on coral reefs may be as high as 36%, with many high-valued species facing the possibility of localized extinction.

Throughout our three-month cruise, researchers will have a unique opportunity to survey diverse locales ranging from the extreme remoteness of Howland and Baker Islands to heavily populated areas of American Samoa. Our data will also be combined with surveys from the Northwestern and Main Hawaiian Islands, Guam, and the Commonwealth of the Northern Mariana Islands to provide an overview of the status and trends of coral reef fish populations in US Pacific waters. Our fish survey method uses a stratified random design where our survey sites are chosen within three depth zones: shallow (1-20 feet), mid (21-60 feet) and deep (61-100 ft) and within each of three general habitat types; fore reef, back reef and lagoon. By using this type of method, we are able to get a holistic view of the fish assemblage at each island we visit.

This is my second trip to Johnston Atoll. During the previous expedition in 2008, high winds and rough seas kept us out of the water for all but two days of the six we had planned. This year the weather cooperated and we were able to survey each of the 5 1/2 days we were at Johnston, allowing us to see much more of the reef environment. I found fish populations at Johnston to be similar to my experiences in the Northwestern Hawaiian Islands. Unlike the Main Hawaiian Islands, we saw sharks on many dives with a maximum of 10 sharks on a single dive. We also saw many large black jacks and other apex predators which is a good sign. On my last dive with Jonatha we were privileged to jump in on a reef with hundreds of spawning blue-lined surgeons. For me it was a unique experience to be in such a large school of fish; something you just don’t get to witness very often in less remote areas.

Thursday, January 28, 2010

Coral Disease

by Bernardo Vargas-Angel

A notable increase in coral disease is one of the most recent concerns pertaining to the resilience of coral reefs worldwide, particularly in light of mounting natural and anthropogenic impacts. Acute diseases have resulted in dramatic coral loss and significant changes in community structure, diversity, and ecosystem function. For example, Acropora white band disease has been recognized as one of the major factors leading to live coral cover reductions of up to 98% in areas of the Florida Keys and the Caribbean.  This loss of coral cover and associated phase-shifts in coral community structure has led to an increase in macroalgae cover and reduced rates of coral reef accretion.


For many years, the threat of coral diseases in the Pacific had been regarded as relatively unimportant based on limited impact sources, inaccessibility, and the spatial vastness of the region. However, increasing evidence indicates an escalating abundance and prevalence of disease throughout Pacific locations, including the Great Barrier Reef, the Marshall Islands, Palau, and the Philippines, as well as the Red Sea and east Africa. The 2002/2003 outbreak of white syndrome in the northern and southern sectors of the Great Barrier Reef, when disease levels increased 20- to 150-fold on outer-shelf reefs, was cause for great concern.


For most coral diseases, the lack of ecological and pathological data hinders a clear understanding of disease causation, virulence, and transmissibility. Moreover, the association between disease and environmental stress still remains largely unknown. Current research supports a connection between environmental deterioration and diminished coral immune capacity, and thus, environmental stress could influence coral disease by altering host/pathogen interactions. Because coral diseases may act synergistically with other stressors, there is reason to believe that management practices may be able to, at least in part, influence the impact of disease.


During this expedition, coral biologists are surveying for coral disease along twenty five meter transects and comparing the results to data from previous years and other areas of the pacific.  Data collected by the scientific crew are pivotal to long-term biological and oceanographic monitoring of U.S Pacific coral reef ecosystems, including the assessment and evaluation for coral diseases.

Concerning Corals

by Jean Kenyon and Erin Looney
photos by Benjamin Richards and Jason Helyer

Stony corals (Class Anthozoa, Order Scleractinia) are marine invertebrates that secrete a calcium carbonate skeleton.  Stony corals can be hermatypic (significant contributors to the reef-building process) or ahermatypic, and may or may not contain endosymbiotic algae called “zooxanthellae”.  The largest colonial members of the Scleractinia help produce the carbonate structures known as coral reefs in shallow tropical and subtropical seas around the world.  The rapid calcification rates of these organisms have been linked to the mutualistic association with the zooxanthellae, found in the coral tissues.  Massive and branching stony corals are the major framework builders of shallow tropical reefs.  Some stony corals occur in deep water and are azooxanthellate (they do not contain zooxanthellae), but these deep water corals typically do not form extensive reefs. Corals are arguably one of the most important components of the coral reef system, providing substrate for colonization by benthic organisms, constructing complex protective habitats for myriad other species, including commercially important invertebrates and fishes, and serving as food resources for a variety of animals.

While at Johnson Atoll we are collecting data on corals that will tell us more about species abundance and distribution, size class distribution, and disease.  Each site we visit differs in terms of species dominance, the relative abundance of coral, and the health of the corals present.  Many factors contribute to this, including the location of the reef (whether it is a backreef, forereef, or in a lagoon), wave intensity, and its closeness to human population and associated pollution.  One would expect that reefs as far removed as Johnston would be pristine, healthy, flourishing environments, but even these are subject to disturbances such as hurricanes, marine debris, and pollutants introduced to the environment throughout history.  Especially in the Pacific, many island which are not currently inhabited, have had sizable human populations in the past. Johnston is one of these and, we find a relatively high prevalence of coral disease at Johnson Atoll compared to other islands.

Although these reefs may not be as pristine as we might hope, they are by far some of the most beautiful and deserve our best efforts in understanding the dynamics that keep them thriving. Every day we are amazed by something new, something we've never seen before (possibly that no one has seen before), and are reminded of why we are out here, trying to learn more about this complicated and amazing environment.

Tuesday, January 26, 2010

All About Algae

text and photos by Peter Vroom


Despite the nonflattering images of “pond scum” many people often associate with algae, marine algae (or macrophytes) have proven themselves to be among the most diverse, most ecologically important, most prevalent, and most beautiful organisms present in tropical reef systems. Their importance to the ecosystem is staggering: algae form the base of the food chain, occupy much of the available substrate, and help to oxygenate the water, allowing animal life to thrive. Additionally, without microscopic symbiotic algae living in healthy coral tissue, most corals would be unable to survive – a scenario that is becoming all too real as coral bleaching events (processes where stressed corals expel their algal symbionts) become more common.


Although large, fleshy algal forms are often the most recognizable floral components on reefs, tiny turf algae and crustose coralline red algae are also extremely prevalent and play significant roles in the ecosystem. Turf algae are the first to colonize vacant substrate and cover essentially every nonliving hard surface on the reef. Turf algae are also among the most important food source for herbivorous fish and invertebrates. Relatively fast growing crustose coralline red algae act as a glue that cements together loose components of the reef system, and serve as a settling surface for larval invertebrates and other algae. Without crustose algae holding everything together, much of the reef would be washed into deep water or onto shore during heavy winter storms.

Clearly, without algae there would be no tropical reef ecosystem, yet marine algae are among the least studied and least understood organisms on the reef. More research is sorely needed to catalog and quantify the species that are present on reef systems around the Pacific, and ecological studies are necessary to examine the role of these critical plants in reef ecosystems.

To accomplish these objectives, CRED is studying tropical reef algae to address the following questions:
  •  What is the best way to quantify algal functional groups (macroalgae, crustose coralline algae, turf algae) in tropical reef settings? 
  •  What species are present in each island ecosystem and in what quantity? 
  •  Do changes in algal populations serve as a good environmental indicator of reef heath? 
  •  How do algal diversity and abundance change over time? 
  •  Can biogeographical hypotheses be formulated about algal dispersal and evolution using qualitative and quantitative data from island groups around the Pacific? 
A modified Rapid Ecological Assessment technique that incorporates the use of digital cameras and photoquadrats is our primary field method, which we will be employing on this cruise.

Monday, January 25, 2010

Our First Days at Johnston

by Benjamin Richards
photos by Kevin Lino, Kara Osada-D'Avella, and Russell Moffitt

Our first two days at Johnston Atoll have been spectacular. In years past we have arrived at the atoll to find howling winds and pounding seas which have kept us from surveying large sections of the exposed forereef areas along the north. This year a gentle swell has been breaking along the northern reefs as gentle breezes come in from the south. We can only hope the weather continues to hold.

Our first half day at the atoll was a shakedown day, which each of the teams used to kick off the "rust" that had built up after several months out of the water. While all are experienced divers, several of the teams have not worked together before and it usually takes a dive or two before they meld into the well oiled machine we see by the end of the expedition.

The towed-diver team started off their surveys along the western forereef where we often see large numbers of grey reef sharks. Sure enough, there they were as soon as we splashed into the water. See sharks out here is a good sign and we are happy each time we see these apex predators which tend to indicate a fairly intact food chain and a healthy reef system.

Our Oceanography team has been able to recover and install a number of instruments which measure sea surface temperature as well as a number of other oceanographic variables during their two year deployment. They were also able to install several calcification plates which are a new deployment for us. These small plates are being installed at various locations around the pacific during this expedition. They will be recovered after two years at which time scientists will measure the amount of calcification which has taken place.  By comparing measurements from various areas over time, we may be able to get a better understanding of ocean-acidification, one of the many threats facing these magnificent reefs.

We were also able to drop off our US Fish and Wildlife Service partners on the main island where they will spend the next few days surveying the local bird, turtle, and other populations. We look forward to their report when we pick them up before heading south to Howland Island.

Saturday, January 23, 2010

Johnston Atoll – extreme isolation

by Beth Flint and Lee Ann WoodwardBiologists, U.S. Fish and Wildlife Service
Tomorrow we will arrive at Johnston Atoll, a remarkable place due to its extreme isolation in the largest ocean in the world.  This tiny spot in the Pacific is critically important to a community of organisms that need shallow water or land to live during at least part of their life cycle. Johnston is the only emergent land in approximately 450,000 square miles of deep ocean. Thus organisms, such as seabirds like the Sooty Tern or the Red-footed Booby, that can forage at sea but need to breed on land or organisms such as Green Turtles, that rely on benthic algae for food, converge at this lonely atoll.  Our jobs during the terrestrail portion of this visit are to estimate population sizes of nesting seabirds, identify and map plant species, and survey and monitor some of the remnants of various human uses of Johnston through the years.

President Calvin Coolidge recognized the atoll’s importance as a wildlife site and designated Johnston Island a National Wildlife Refuge back in 1926. In 1934 President Roosevelt added a military mission to the area and for the next 70 years the government used the atoll in a variety of capacities; as a base during Viet Nam, for the testing of nuclear weapons, and for the storage and disposal of chemical weapons.  During the 1950’s and 1960’s there were as many as two thousand people living at Johnston. The main island at Johnston was originally about 64 acres, however, it was enlarged in various dredge and fill operations to its present size of about 633 acres.  In addition to enlarging the existing islands, the military also created two new islands, North (Akau) and East (Hikina). The dredging destroyed some of the extensive coral reefs but much remains. The military has ended their mission at Johnston and departed the atoll in 2004 after several years of clean-up activities.  Now Johnston has been returned to the wildlife that had it in the beginning and where there once were buildings, seabirds are again.

In January of 2009 President George W. Bush expanded protection of the waters around Johnston Atoll out to 50 miles as part of the new Pacific Remote Islands Marine National Monument.
Fifteen kinds of seabirds are once again nesting in great profusion at Johnston, in shrubs, on the ground like these Sooty Terns, and underground in burrows and rock crevices. The thing they all have in common is that they feed hundreds of miles out to sea but come here to lay their eggs and feed their chicks.

Thursday, January 21, 2010

Heading out to sea

by Benjamin Richards

Our date of departure has finally arrived.  We cast off lines at just after 1:00 this afternoon and are now steaming southwest towards Johnston Atoll.  We have a stiff breeze and a following sea which makes the ship roll gently back and forth over the waves.  The past few weeks have been exhausting and that, combined with the steady rocking of the ship has sent most of the science party to their bunks for some much needed rest.  Tomorrow we start in early on our shipboard preparations with an overview and re-familiarization of our small boats at 0800 (8:00 am) followed by our standard suite of safety drills and pre-dive medical exams. Once those are complete, its time to get to work on the final phase of gear preparation before our arrival and Johnston.

Wednesday, January 20, 2010

Getting ready to go


As our date of departure draws closer, each of the research teams is hurrying to finish their final preparations, organize their equipment and get it loaded aboard the Hi'ialakai. A steady stream of crates, pallets, Action packers, Pelican Cases, and 5-gallon buckets can be seem making their way from laboratories, to pickup trucks and then up the gangway and into the ship. Fuel trucks pass to and fro, cranes are lifting the heavy equipment from the pier to the ship, and the electronics technicians are running the last of the cables to connect the various computers and other pieces of equipment used to collect a variety of different measurements while we are underway.  Piles of equipment appear in various locations and then disappear almost as quickly as they appeared.  There is a constant flurry of activity and it looks like we might just get underway as scheduled.

Friday, January 15, 2010

Who are we and what do we do?

by Benjamin Richards


This year we will be sailing with 22 scientists from NOAA Coral Reef Ecosystem Division and the US Fish and Wildlife Service.  We are a multidisciplinary team of researchers who study the oceanography, fish, coral, algae, invertebrates and birds that live in and around the remote reefs and atolls of the U.S. Pacific Islands. Our main objective is to continue monitoring for natural or anthropogenic (human-induced) fluctuations in the reef communities and to document the range of species (or biodiversity) that exists in various reef habitats.  As our data set grows we are also working to identify patterns of habitat use and species' interactions. During this research cruise, teams of divers will be surveying the reef communities, recording species abundance, diversity, and spatial distribution for all four of these key components of the ecosystem. Our US Fish and Wildlife Service colleagues will be going ashore on various islands to study and monitor the local bird and sea turtle communities.




During the cruise we will be conducting three main kinds of SCUBA surveys: towed-diver surveys, Rapid Ecological Assessments (REAs), and Stationary Point Counts (SPCs), each of which is designed to gather information on a different part of the reef community. Biological data from these surveys can be analyzed in the context of oceanographic conditions and benthic habitat maps to help us understand how coral reefs function as an interconnected ecosystem.



Over the past 10 years, our main research objectives have been to:
  • Document baseline conditions of the health of coral reef living resources (fish, coral, algae, and invertebrates) in the U.S. Pacific Islands.
  • Refine species inventory lists of these resources for the island areas.
  • Monitor these reef resources over time to quantify possible natural or anthropogenic impacts.
  • Document natural temporal and spatial variability in the reef resource community.
  • Improve our understanding of the ecosystem linkages between and among species, trophic levels, and surrounding environmental conditions.
We hope you will join us to learn more as we continue our explorations of this amazing world beneath the waves ...