Published Date: 2012-11-20 02:49:28
Subject: PRO/AH/EDR> Coral reef kill - USA: (HI)
Archive Number: 20121120.1416225
CORAL REEF KILL - USA: (HAWAII)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Sun 18 Nov 2012
Source: The Garden Island [edited]
A rapidly-spreading coral disease along Kauai's North Shore may be affecting turtles, fish, and even humans, according to a team of scientists.
A year ago, Dr Greta Aeby, a coral expert with the Hawaii Institute of Marine Biology at the University of Hawaii, sent out an alert to scientists and divers about a disease affecting corals in Kaneohe Bay on Oahu.
When Terry Lilley, a marine biologist and scuba diver in Hanalei, received the alert, he said he became concerned because it sounded similar to what he had seen and filmed -- but could not identify -- in reefs on Kauai.
As it turns out, the disease is similar to that seen on Oahu, which is eating the coral at lightning speeds, according to Lilley, who graduated with a degree in biological sciences from California Polytechnic University, San Luis Obispo, in 1980. As the black-colored bacteria moves through the coral, it strips off live tissue, leaving a white, dead skeleton exposed.
"The fascinating part is this disease has gone out of control and could potentially wipe out the reefs," he said. "We don't know where this bacterium came from. We don't know how it spreads."
A year ago, Lilley began filming infected rice corals along the North Shore. At that time he said he documented 100 infections at 20 different dive locations. Today [18 Nov 2012], he said the number of infected coral is likely in the millions.
"Last summer , for some unknown reason, the infection rates went up to 100 infections per dive, to where now, at a number of sites, there are so many infections we are counting the corals that are not infected," he said. "Every place along the North Shore we are finding this stuff, and a lot of it."
After reviewing older underwater video footage he shot along Kauai's North Shore, Lilley tracked the disease back to 2007, which he said is important for giving scientists a timeline.
The white coral disease outbreak is believed to be caused by a new strain of cyanobacteria, unique to Kauai, which is killing corals that often take 50 years to grow at a rate of 1 to 2 inches [2.5-5 cm] per week, according to Lilley.
"There seems to be an unknown fungus working with these bacteria ... in my career as an investigative biologist, I have never been stumped to a degree such as this."
Over the past few months, a rapid response team of top scientists -- including Aeby and Dr Thierry Work, head of Infectious Disease for the US Geological Survey -- have been involved in a disease study along Kauai's North Shore.
In August , Work traveled to Kauai and did extensive DNA and toxicology testing on the disease at Tunnels Reef. An official report was filed 4 Sep 2012 by the USGS outlining the reef's poor condition.
"Because of the extensive mortality evident from Mr Lilley's photos, we (USGS) decided to carry out a field investigation to sample corals in attempts to figure out what may be causing this mortality," Work writes in the report. "The overall picture was one of a severely degraded reef impacted by sediments and turf algae. ... It is tempting to conclude that degraded conditions of the reef could have precipitated infection by fungi and cyanobacteria leading to the lesions seen here, however, confirming this would require longitudinal studies and more systematic sampling over time."
Work returned to Kauai in early October  to perform a 2nd round of detailed testing. "They not only did DNA testing but they took samples of this fungus for toxicology studies and they took samples of the water column, to see if this disease is actually floating around in the water," Lilley said.
A full report of Work's DNA, bacteria, and toxicology study is expected to be available within the next month or so.
At this point, Lilley says the disease outbreak is no longer just his own opinion, which he admits has been called into question in the past, but a "mathematical equation." "This needs everyone's attention," he said. "If we lose our coral reefs on Kauai, it's not only going to affect the marine life ... it's going to affect you and me."
After confirming the disease in early October , Aeby and her team began treating infected corals in Anini Bay with a type of marine epoxy, similar to a fire break approach, in an attempt to try and stop its spread.
"It is working," Lilley said. "Most of the epoxy barriers we put down did stop the disease from spreading across the coral ... that's the good news." But the problem along the North Shore is that the disease is so widespread, with upwards of 1 million affected coral, according to Lilley.
"This study is more for helping other places, not the North Shore," he said. "There is no way we can physically stop it at this point." Instead, the team of scientists is looking for ways to control the disease should it surface in other locations.
Another big concern is whether this new strain of cyanobacteria could be infectious to humans and marine life. "I believe it is already affecting marine life," said Lilley, who claims to have filmed turtles with large tumors and puffer fish with fins that are rotting and falling off.
The question of whether there is a connection between the dying coral and diseased marine life is still to be determined by Aeby, Work, and other scientists involved in the ongoing study.
While Aeby and Work continue to search for a cause and cure, Lilley is monitoring and documenting its spread with underwater video equipment.
The biggest setback of the ongoing study, according to Lilley, has been financial insufficiency. "Most 3rd-world countries that I've been in communication with, including the Cook Islands -- we're talking about places that aren't wealthy -- put 1000 times more resources into studying their marine environment than Kauai," he said. "I've been all around the world and I've never seen any island that is more understudied than Kauai."
Lilley said his concern is not that future generations won't be able to enjoy Kauai's coral reefs. "I'm extremely concerned about whether or not you, on your next trip back to Kauai, 10 years from now, are going to be able to see a coral reef."
[Byline: Chris D'Angelo]
ProMED-mail from HealthMap alerts
[At the beginning of 2012 ProMED-mail posted a report on Montipora white syndrome in Hawaii (archive no 20120109.1004413). It is unclear how related this outbreak might be to that disease. In the text, there's mention of a new strain of cyanobacteria. In general, cyanobacteria play a beneficial role for coral reefs. There's also mention of a fungus. _Aspergillus sydowii_ is a marine fungus known to cause mortalities in sea fans (_Gorgonia_ spp.).
Coral diseases have multiple interacting causes. Coral reefs worldwide are threatened by increasing anthropogenic stressors, particularly overfishing and the problems associated with global climate change. Coral disease is recognized as another problem causing the degradation of reefs, which is demonstrated by a global increase in the numbers of coral diseases, coral species affected, and disease outbreaks. This is especially true in the Indo-Pacific, where coral disease has recently been recognized as a problem.
A map of the affected area can be accessed at http://healthmap.org/r/4965. - Mod. PMB]