It's not unusual for warm weather to prevail in Hawaii but with last September causing underwater temperatures to rise as high as 86 degrees, a few problems started to creep up, one of which is coral bleaching.
When algae leave when the water is too warm, it starves the coral, making it turn white. Coral bleaching is actually a normal occurrence during this time of the year but the current phenomenon is worse than scientists expected.
According to Anne Rosinski, a marine resource specialist from the Hawaii Department of Land and Natural Resources' Division of Aquatic Resources, about 75 percent of major coral species in Kaneohe Bay have been showing signs of bleaching, ranging anywhere from mild paling to completely white. Those that have gone completely white represent corals at their most vulnerable.
Unfortunately, coral bleaching is not restricted to Kaneohe Bay. Reports are also coming in that Hanauma Bay, a popular spot for snorkeling, the Big Island, and Maui have coral bleaching cases, according to the DAR. Shallower waters are showing more coral bleaching though, with conditions in Oahu's windward coast especially severe.
As it is, corals already face a number of stress factors, like pollution, invasive algae, and sedimentation. With warmer waters in the picture, corals have to deal with more problems, making them more susceptible to damage.
"The corals are animals, right, they're not rocks. So what bleaching is, it's a sign of distress," explained Hawaii Director of Marine Programs for The Nature Conservancy, Kim Hum.
The level of coral bleaching manifesting in Hawaii right now is worse than what the island experienced in 1996. Nearly all corals affected managed to recover from the bleaching that occurred early in that year but researchers aren't as optimistic now given that the phenomenon is happening in the year.
Researchers are also expecting coral bleaching to become worse in the next four to six weeks until the weather starts cooling naturally. But should trade winds return sooner, the situation may improve sooner as well.
While the coral bleaching in Hawaii is attributed to higher water temperatures, warmer water isn't always the cause of a bleaching event.
In January 2010, corals were bleached along the Florida Keys when water temperatures dropped 12.06 degrees lower than the usual temperature for that time of the year. Researchers have determined that the cold can also lead to bleaching in the same way that warm water does because it stresses corals, making them more likely to succumb to damage and disease.