Expedition to Establish Long-term Monitoring Sites to Measure Trends on Coral Reefs in the Northwestern Hawaiian Islands

September 3, 2013
A diver searches for locations to deploy monitoring instruments at French Frigate Shoals during the 2010 Pacific RAMP expedition.
A diver searches for locations to deploy monitoring instruments at French Frigate Shoals during the 2010 Pacific RAMP expedition.
Calcification accretion units (CAUs), like this one installed in 2010 on a reef at French Frigate Shoals, are used to monitor rates 
                 of net calcium carbonate accretion.  CAUs are deployed for 3 years during which time crustose coralline algae and hard corals 
                 will colonize the units. Data gathered with the units help scientists measure the effects of ocean acidification on corals and other 
                 organisms with carbonate skeletons. NOAA photo by Cristi Richards.
Calcification accretion units (CAUs), like this one installed in 2010 on a reef at French Frigate Shoals, are used to monitor rates of net calcium carbonate accretion. CAUs are deployed for 3 years during which time crustose coralline algae and hard corals will colonize the units. Data gathered with the units help scientists measure the effects of ocean acidification on corals and other organisms with carbonate skeletons. NOAA photo by Cristi Richards.
Subsurface temperature recorders will be installed to provide long-term monitoring of environmental conditions on coral reef ecosystems of the 
                 Northwestern Hawaiian Islands.
Subsurface temperature recorders will be installed to provide long-term monitoring of environmental conditions on coral reef ecosystems of the Northwestern Hawaiian Islands.

Scientists of the NOAA Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division (CRED) embarked today on a 19-day mission aboard the NOAA Ship Hiʻialakai to establish a network of long-term monitoring sites in the Northwestern Hawaiian Islands, a conservation area designated as the Papahānaumokuākea Marine National Monument (PMNM). This expedition is an extension of the coral reef research and monitoring that CRED has been conducting for more than a decade within the Northwestern Hawaiian Islands and is an element of the National Coral Reef Monitoring Plan of NOAA's Coral Reef Conservation Program.

The research expedition is part of the CRED's long-term, integrated Pacific Reef Assessment and Monitoring Program (Pacific RAMP), which is designed to provide a flow of consistent, comparable information to help document and report the status of environmental conditions and living resources of the nation's coral reef ecosystems in the Pacific. Long-term data will enable scientists to study trends in the ecosystems over time and the effects of human activities and natural processes that influence the coral reef environment and biota. The scientific team includes CRED staff who are employees of the Joint Institute for Marine and Atmospheric Research of the University of Hawaiʻi at Mānoa and research partners from San Diego State University, Scripps Institution of Oceanography of the University of California San Diego, the NOAA Diving Center, and the University of Hawaiʻi at Mānoa.

With the Hiʻialakai as their base of operations, scientists will conduct scuba dives from small boats to install instruments at 15 long-term monitoring sites around Pearl and Hermes Atoll, Lisianski Island, and French Frigate Shoals. These sites will add to the 5 monitoring sites set up at Kure Atoll earlier this summer by CRED scientists, bringing to 20 the total number of monitoring sites throughout the Northwestern Hawaiian Islands.

The main goal of the research mission is to advance a robust set of methods to be used at these long-term monitoring sites to measure changes in ocean temperature and ocean chemistry as a function of climate change and ocean acidification. Measuring changes in oceanographic parameters over long periods and concurrently monitoring many subsequent biological responses on the reef will allow NOAA scientists to assess the effects of changing ocean chemistry and temperatures on the coral reef ecosystems in the Northwestern Hawaiian Islands.

To achieve a comprehensive understanding of biological, physical, and chemical processes that affect a reef, CRED researchers will use many techniques. Ocean temperatures will be measured with instruments deployed at depths of 1, 5, 15, and 25 m along selected transects on the forereefs surrounding each island or atoll. These instruments are capable of recording subsurface ocean temperatures every 5 min for a period of 3 years. At the site where the temperature sensor is deployed at each island, other instruments will be employed to collect additional measurements. Discrete water samples will be collected and analyzed for salinity, dissolved inorganic carbon, and total alkalinity to evaluate the carbonate chemistry of waters just above the reef. Casts with a conductivity-temperature-depth instrument will be made to profile salinity and temperature of the water column from the sea surface to seafloor. Within the reef matrix, the following monitoring installations will be used: calcification accretion units to assess net rates of calcification, coral recruitment, and algal biomass; bioerosion monitoring units to provide measurements of bioerosion rates across the reef, and autonomous reef monitoring structures to aid in assessment of taxonomic diversity at the species level. Photographic and video mosaic techniques will document the percent cover of corals and algae found on the seafloor.

This 2013 expedition will add to information collected during monitoring and mapping surveys conducted in the Northwestern Hawaiian Islands in 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2008, and 2010. Data collected in these surveys are pivotal to long-term biological and oceanographic monitoring of coral reef ecosystems in the Hawaiian Archipelago. In particular, these data allow scientists to evaluate changes in the condition and integrity of the coral reef ecosystems and enable federal and state resource managers to more effectively manage and conserve reef-associated sea life in the region.

Operating area for the expedition encompasses the waters of the Northwestern Hawaiian Islands.
Operating area for the expedition encompasses the waters of the Northwestern Hawaiian Islands.