PRINCEVILLE — Something in Kauai’s marine environment has changed, allowing for an outbreak of what scientists have confirmed as black band coral disease on the island’s North Shore.
Once a coral colony is infected, the disease kills it at an average of 4.5 centimeters per week, according to Christina Runyon, a graduate research assistant at University of Hawaii’s Institute of Marine Biology.
”There is substantial death that happens when this moves across the colony,” she said.
The good news — potentially — is that Runyon has seen a “slowing down.”
”The majority of our colonies that we just visited last week, they are not showing signs of the disease right now,” she said.
However, that doesn’t mean it won’t increase again, as lesions have been found to be more active during the summer months.
How Runyon and others members of the Kauai Management Response Team are working to address the outbreak and pinpoint potential causes were topics of a public meeting Wednesday evening at the Princeville Public Library.
Nearly 100 people attended the event, with many forced to stand in back.
North Shore resident Tina Ferrato said she came out because she cares deeply for the environment, particularly coral reefs, and described the presentation as informative and professional.
”Any opportunity I get to learn, I do,” she said.
So far, the cyanobacterial disease — first spotted in 2004 — is targeting three species of Montipora, or rice, corals — including the blue rice coral, one of 66 coral species being considered for protection under the Endangered Species Act.
As part of her Ph.D. research, Runyon is looking into disease distribution, prevalence and virulence, as well as identifying the key pathogenic bacteria associated with it. This summer, she has been resurveying reefs around Kauai and collecting data, which will be compiled into a report this fall.
”Something that we were able to see is that over time this disease seems to wax and wane,” Runyon said, speaking during the event via Skype from Oahu.
In other words, experts have noticed higher disease prevalence and distribution rates at different times of the year.
”We have a lot more data right now that we’re working up so we can give a little better picture, but we believe this disease is seasonal, and that warmer water actually drives the potential for this cyanobacteria and the other bacteria to take off and cause disease in corals,” Runyon said.
In addition to “hot spots” around the island, higher disease rates have been documented in specific locations within individual reefs. Some of the hardest hit areas include Kee, Anini and Makua (Tunnels).
So far, 38 sites (25 on the North Shore and 13 on the South Shore) have been surveyed, with BBD being discovered at 19. All were located on the North Shore, with the exception of Ahukini, on the Eastside.
One interesting point was raised by Matt Rosener, a project manager and hydrologist at the Waipa Foundation. He questioned whether water temperatures could be ruled out as a factor given current warm water conditions.
Although still present, Runyon said disease levels are not as high as October 2012. Additionally, water temperatures are still climbing and will reach their peak in September and October, which Runyon said will be a good time to get back in the water and survey.
”Increased temperature does promote the growth of the bacteria,” she said after Wednesday’s meeting.
One audience member raised concerns about whether the disease could pose a risk to human health. Runyon said it’s hard to say because she hasn’t identified every bacteria involved.
”I can tell you I’ve now worked with these pathogens for over a year and I’m not sick,” she laughed. “So I don’t see that they have major human health potential, but we don’t know the answers to everything yet.”
Katie Nalesere, education specialist for the Department of Land and Natural Resources’ Division of Aquatic Resources, led the presentation and described Kauai’s North Shore as a unique and harsh environment for corals. Heavy wave energy and high freshwater input, turbidity and sedimentation has led to an overall low coral cover, averaging just 14 percent.
”What we do know about the corals there though, they are strong,” she said. “They’ve been there for a very long time. They’ve learned to adapt to that environment.”
Like any other living animal, corals are susceptible to disease.
”One good thing is it keeps our populations in check,” Nalesere said.
The KMRT, which includes partners from the National Oceanic and Atmospheric Administration, the Environmental Protection Agency, USGS and UH, will continue to review the latest data about the disease, identify the next steps in research and consider management options.
Also in attendance Wednesday was Frazer McGilvray, administrator for DLNR’s Division of Aquatic Resources. He said that when he took over the position it made him realize that “in the land of the blind, the one-eyed man is king,” and that “there was no information on anything coming out of” the division.
McGilvray found that to be “unacceptable.”
”To me it’s key. The public has to know what the government is doing and what the state of the oceans are,” he said. “And not just kind of a, ‘Ah, wash it under the carpet,’ when everybody who actually goes in the water and can see things knows it’s not fine. So, I’m looking for facts, I’m looking for truth and I’m looking for science.”
Steve Sobel, of the Princeville Public Library, said that in terms of what can be done in the future, he felt it was important to realize what was accomplished with Wednesday’s gathering.
”This was kind of like a summit meeting,” he said. “If you think about all the people that were in this room, and all the people that interacted, I wonder if this many people and this much knowledge has been in one room talking about this subject before.”
More information about the Kauai coral disease response effort can be found at dlnr.hawaii.gov/reefresponse.
Nalesere will lead a Create Your Own Coral Colony workshop from 10:30 to 11:30 a.m. Saturday at the library. Participants will learn about the life of coral and the important role it plays in the reef ecosystem, and get to color, mold and create their own coral colonies out of clay.
Chris D’Angelo, environment writer, can be reached at 245-0441 or firstname.lastname@example.org.