A team of scientists with the National Oceanic and Atmospheric Administration has returned from a monthlong trip to Papahanaumokuakea Marine National Monument with reams of research on coral and fish populations.
The new information is expected to help scientists and government managers build on their understanding of marine life in the Northwestern Hawaiian Islands and the threats that climate change present there as well as in the Main Hawaiian Islands.
Atsuko Fukunaga, the expedition’s chief scientist, said Saturday that in general the reefs “seem to be doing good” this year but some sites are still recovering from severe coral bleaching over the past few years. Atsuko is an ecological research statistician for PMNM with the Joint Institute for Marine and Atmospheric Research at the University of Hawaii-Manoa. She and the rest of the team will be unpacking and analyzing the data to make a more precise health assessment in the coming months.
Roughly 20 scientists, with help from three University of Hawaii students, took thousands of underwater photos of corals at some 200 sites around French Frigate Shoals, Lisianski, Kure, Pearl and Hermes, Laysan and Midway atolls during the 25-day trip. They also deployed baited remote underwater video stations to survey sharks and fish populations. The scientists were from from NOAA’s Office of National Marine Sanctuaries and Pacific Islands Fisheries Science Center, JIMAR, UH-Hilo and the Australian Institute of Marine Science.
NOAA funded Colton Johnson, Keelee Martin and Roseanna Lee as interns through the UH-Hilo’s Quantitative Underwater Ecological Surveying Techniques program.
“You’re kind of shot out of the cannon at first,” Lee said. “You learn so much, so fast.”
Even with all the training at school, she said, “you can’t get that kind of experience anywhere else.”
John Burns, a benthic habitat researcher for PMNM also working through JIMAR, shared samples of the high-resolution 3-D modeling he does of the reefs to assess their health in ways that weren’t possible when he started going to the monument six years ago.
“You can really see exactly how the reef changes when some corals die and new ones start to grow,” he said, noting that the modeling allows scientists to zoom in and see within a millimeter accuracy.
“If we’re going to understand the health of corals, we need to know what the structure and dynamic of that habitat is,” he said. “Each species is different in terms of how it might respond to increases in seawater temperature or changes in environmental conditions.”
There were record ocean temperatures in 2014, 2015 and 2016. The Northwestern Hawaiian Islands experienced its most widespread coral bleaching event in 2014, which was followed by the third global bleaching ever recorded that began in 2015 and ended this past June.
The reef around Lisianski Island, which is about 900 miles northwest of Honolulu, was hit particularly hard. Roughly 90 percent of the corals died, said Randy Kosaki, the monument’s deputy superintendent for NOAA.
As a result, that island has become a routine stop for the scientists who make annual reef-monitoring trips to the monument aboard NOAA’s Hiialakai research vessel.
The study underscored the need to significantly reduce carbon emissions that are causing climate change.
The article also highlights how the work being done in the monument helps scientists understand what’s happening in the Main Hawaiian Islands.
While both places are susceptible to rising ocean temperatures, the Northwestern Hawaiian Islands are mostly free of direct human threats since they are protected by the monument. That can help scientists determine the extent to which fishing, pollution, sediment runoff and other stresses in the Main Hawaiian Islands play in corals’ ability to adapt to warmer waters and become more resilient to bleaching.
The new data is also expected to help scientists understand how stressed coral reef ecosystems may recover and refine their ability to pinpoint susceptible and resilient coral reefs.
Below is a video by Audrey Schlaff of the Australian Institute of Marine Science that shows how a baited remote underwater station is used to survey fish in Papahanaumokuakea.