Although the National Oceanic and Atmospheric Administration (NOAA) sent out an alert Thursday warning area scientists that coral bleaching could be a problem this summer, one St. John-based scientist said he’s keeping the same watchful eye he does every summer.
"Our response is we’ll keep looking at this," Jeff Miller, a fisheries biologist with the National Park Service’s Inventory and Monitoring Program, said Friday.
Miller recently returned from diving 170 sites around St. John with National Park and NOAA scientists. "We did see some corals that were a little paler than they typically are," he said.
He said the paleness occurred in some deeper plate corals such as lettuce and sheet varieties. Miller said those types are vulnerable to warmer water.
He hopes that weather systems passing through the territory as the summer progresses keep the water "mixed up" and therefore cooler.
"We could get a large rain or waves that affect the water temperature," Miller said.
NOAA’s coordinator of its Coral Reef Watch, C. Mark Eakin, issued the coral bleaching alert. He said Friday the models that predict coral bleaching could be a problem in the Virgin Islands and Puerto Rico are similar to those developed after the summer of 2005. In that summer, the territory’s corals suffered epic bleaching and the number of hurricanes that formed reached an historic high.
Eakin said that NOAA didn’t have the ability in 2005 to make these predictions, but did what it called a hind cast.
The models are based on "thermal stress," which Eakin defined as water temperatures that are warm enough to cause harm to corals.
As it did in 2005, if coral bleaching occurs it should reach its peak in September and October, the territory’s hottest months, Eakin said.
Bleaching occurs when unusually warm water or other factors cause the corals to expel the algae that gives corals their color.
"If it’s mild they can recover. If it’s serious, they can die," Eakin said.
NOAA’s website reports that, globally, last month was the warmest June on record — higher even than 2005 — when it comes to ocean sea surface temperatures. Eakin said that factor is linked to what the models show might happen to corals this summer.
"It is likely that continued high temperatures will cause stress to corals," he said.
Miller, based at V.I. National Park on St. John, hasn’t had a chance to look at the water temperature records for 2005 because he’s been out diving, but he said they’re running 84, 85 and in some places 86 degrees.
"That’s what is expected for this time of year," he said.
Miller, a one-man band for treating coral well, said that with yet another threat, it’s vitally important to protect what coral remains.
"We have to control sedimentation, nitrification, anchoring, fishing, littering. All of these things," he said, pointing out that coral reefs are vital to the territory’s tourism-based economy.
Zandy Hillis-Starr, a scientist at Buck Island Reef National Monument and a coral expert, could not be reached Friday for comment on the situation on St. Croix.
