"The most extensive living coral reef in the United States is adjacent to the island chain of the Florida Keys. The Florida Reef Tract which extends from Soldier Key, located in Biscayne Bay, to the Tortugas Banks possesses coral formations very similar to those found in the Bahamas and Caribbean Sea. The Florida Reef Tract is nearly 150 miles long and about 4 miles wide extending to the edge of the Florida Straits. It is the third largest barrier reef ecosystem in the world. All but the northern-most extent of the reef tract lies within the boundaries of the Florida Keys National Marine Sanctuary. The 2,800 square nautical mile Florida Keys National Marine Sanctuary (FKNMS), designated in 1992, surrounds the entire archipelago of the Florida Keys and includes the productive waters of Florida Bay, the Gulf of Mexico and the Atlantic Ocean."
So describes NOAA's Coral Reef Information System on the shallow reef formations off the coasts of South Florida.
NOAA Climate.gov map by Dan Pisut, based on degree heating week data from NOAA’s Coral Reef Watch Project. Caption by Caitlyn Kennedy
This map shows accumulated coral heat stress in the tropical Atlantic and Caribbean as of the week of September 21, 2014, when Florida was observing its highest level of stress. Reef locations are shown as black dots. (Where the dots are close together they make lines and other shapes).
Below 4 weeks (light yellow), heat stress was not enough to trigger bleaching. Beyond four degree-heating weeks (gold to orange) widespread coral bleaching becomes likely, and beyond 8 weeks (salmon to dark pink), significant bleaching and death become possible. Areas shown in white had not experienced heat stress sufficient to cause bleaching during the previous 12 weeks.
Climate.gov reports:
An outbreak of coral bleaching—the loss of corals’ food-producing algae—in the Pacific and the Caribbean occurred this past summer, most likely tied to a brewing El Niño. The reefs of the Florida Keys observed their worst bleaching impacts since 1997-1999, when a major El Niño was quickly followed by a major La Niña. The surprising intensity of bleaching across multiple ocean basins in 2014 has scientists wondering what to expect in 2015, when El Niño is forecasted to finally develop.
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Under sustained heat stress, corals expel the symbiotic algae that live inside the corals and produce much of their food (through photosynthesis). Losing their algae causes the corals’ vibrant colors to fade to white—bleaching—and corals may starve or catch diseases during prolonged stress. Heat stress in corals is described by degree heating weeks: the number of degrees the water temperature is above the local summertime maximum times the number of weeks it remains there.
Beyond the Florida Keys, the main Hawaiian Islands experienced their worst bleaching on record, and a record level of heat stress was observed in the Northwestern Hawaiian Islands. In a recent Diving Deep podcast, Mark Eakin, NOAA’s Coral Reef Watch Coordinator, spoke about how these widespread bleaching events have been surprisingly severe even without a strong El Niño underway.
“We've been worried about 2015 and have been concerned about what this El Niño was going to do for the last six months,” he said. “What we didn't know was how bad 2014 was going to be even before we got that El Niño fully formed.”
One of the most devastating bleaching events on record was associated with what has been argued to be the largest documented El Niño (1997-1998), followed immediately by a strong La Niña (1998-1999). Coral Reef Watch’s research has even shown that some major coral reef areas that do not warm up during an El Niño are still impacted by warming during a La Niña, meaning coral bleaching can be particularly severe during back-to-back El Niño/La Niña events.
Since March 2014, NOAA's National Centers for Environmental Prediction has been calling for an El Niño to develop in late 2014. The present forecast suggests that if an El Niño develops this year, it’s likely to be weak. However, even a mild El Niño like the event in 2010 can cause bleaching around the world. (See a global map of coral bleaching thermal stress from 2010 in NOAA View.)
“[In] 2010 we had a mild El Niño, but yet we had the very same pattern of global bleaching going on—not as severe, but a lot of places were hit very badly,” Eakin said. “We're concerned about this El Niño because of the warming we're already seeing…even a small El Niño is likely to cause a lot of bleaching in 2015.”
A dolphin gravely ill with morbillivirus lies in the surf of the Bahia Honda State Park Beach. HEATHER BAERTLEIN — NOAA
An emaciated bottlenose dolphin washed up on the tiny island of Bahia Honda in the Florida Keys. The necropsy report came back positive for morbillivirus and scientists describe the result as the worst case scenario.
Up to 50 percent of the Keys' endemic bottlenose dolphin population could die as a result of the recently discovered southern spread of the morbillivirus (Cetacean morbillivirus affects the lungs, brain and immune system. In the dolphins that tested positive for this virus, many of them had skin, oral, and lung lesions, additionally some had presumptive secondary bacterial or fungal infections.) outbreak from the Indian River Lagoon.
Heather Baertlein Of NOAA explains below.
Until now, Keys' bottlenose dolphins were considered a "naïve population," meaning the endemic mammals had not been exposed to the virus. Not having morbillivirus here is a good thing, but it also means that Keys dolphins do not have the antibodies in their system to fight off the disease should they become exposed. This makes the population prone to a large die-off.
"Everyone was really hoping it wasn't going to move south of Brevard County," said Jill L. Richardson, a biologist with the University of Miami's Rosenstiel School of Marine and Atmospheric Science. "Because this is a semi-naïve population, it's pretty upsetting it has been identified in the Keys."
Federal fisheries scientists declared this week that the outbreak area of the virus, which has killed 1,569 dolphins from New York to Central Florida since July 2013, now includes the Atlantic side of the Keys. And the entire Gulf of Mexico and Florida Bay side of Florida is now considered a "surveillance area" for the outbreak, said Laura Engleby, a biologist and chief of the National Oceanic and Atmospheric Administration's southeast marine-mammal branch.
Keys Info Net notes the likelihood of the virus infecting dolphins at the Dolphin Research Center.
Unlike marine parks like SeaWorld and the Miami Seaquarium, Keys captive marine mammal facilities' holding pens are fed water directly from the ocean, bay and Gulf of Mexico. Nevertheless, their operators, although on alert, don't think morbillivirus will impact their mammals since the animals seldom, if ever, come into direct contact with wild whales and dolphins.
But Bossart said facility managers should be extra cautious because there may be other ways morbillivirus can spread.
"We're still not sure of other modes of transmission," he said. "I would be a little bit more uncertain at this point."
Bossart, a comparative pathologist, has particular concerns about the latest outbreak because, as he puts it, dolphins are "sentinels for ocean and human health." The last major morbillivirus was in the late 1980s and early '90s. Before that, there wasn't even a test for the virus. The resurgence of the disease and other deadly illnesses in the ocean “suggest our ocean environment is under stress."
Bossart says morbillivirus is really just the tip of the iceberg and that what is happening in the ocean could be a reflection of what is happening on land. He pointed to deadly terrestrial illnesses making a comeback, including Ebola, Middle East respiratory syndrome and malaria.
"There's not only concern for dolphins, but also for us," Bossart said.
It's all about the water. Tick, tick, tick...