Skip to main content
U.S. flag

An official website of the United States government

October 25, 2017

Coral reef expert Caroline Rogers was the only USGS employee in the Virgin Islands when the Category 5 storm hit.

September was a life-changing month for the 31 U.S. Geological Survey employees based in the United States’ Caribbean islands, as two dangerous hurricanes struck the U.S. Virgin Islands and Puerto Rico less than two weeks apart. USGS staffers and their families endured potentially deadly wind and flooding from Category 5 Hurricane Irma, Category 4 Hurricane Maria, or in some cases, both. In Puerto Rico, USGS employees are back at work under challenging conditions. It will be many months before normalcy returns, but all 30 Puerto Rico-based employees’ homes are intact.

Hurricane Hole, St. John, US Virgin Islands
In 2009 USGS coral reef expert Caroline Rogers found three of the small bays in St. John, USVI’s Hurricane Hole shelter an unusual diversity of coral species. Photo: Caroline Rogers, USGS.

For Caroline Rogers, an internationally known expert on coral reefs and the only USGS employee stationed in the Virgin Islands, Hurricane Irma swiftly wiped away normalcy at home, at work, and in the field.

On September 6 Hurricane Irma was at the peak of its strength—with top sustained winds of 185 miles per hour and 225-mile-per-hour gusts, according to the National Hurricane Center—when it struck the island of St. John, where Rogers has lived and worked as a marine biologist since1984. Rogers rode out the hurricane with friends in a concrete home. At the height of the storm, she felt the solid walls trembling. By day’s end, Rogers’ wooden house still had its roof, although two windows were smashed, and nearby homes had become piles of broken wood. Her office in a National Park Service building at Virgin Islands National Park was roofless. Its walls had exploded, and her books, papers and most of her equipment were ruined.

Brain corals, mangrove prop roots and squirrelfish
Sediment can smother corals, but Hurricane Hole has no sediment-bearing freshwater streams. Its clear waters are habitat for an entire community of marine life, including Montastrea corals and squirrelfish. Photo: Caroline Rogers, USGS, 2009

And the hurricane had profoundly altered the unique ecosystem Rogers discovered in 2009 and has been monitoring since then – a group of mangrove-lined bays sheltering 30 hard coral species that are normally found on deeper reefs. The corals in the bays known collectively as Hurricane Hole, within the Virgin Islands Coral Reef National Monument, have apparently withstood high sea temperatures that have killed corals across the Caribbean.

After Irma, the red mangroves that shaded and protected Hurricane Hole were broken and leafless. The bays were an obstacle course of capsized and sunken boats leaking fuel into waters that once were glassy clear.

“I have been through many hurricanes, but this one was off the charts,” said Rogers. “Still, so many people I know lost everything that when people ask me, ‘How did you do?’ I just say, ‘I did okay.’ ”

Rogers is an expert on corals’ response to disturbances such as hurricanes, high sea temperatures, heavy sedimentation and diseases. The corals she discovered in the Hurricane Hole bays are beautiful, and part of a natural community that serves as vital nursery habitat for abundant fish and shellfish. They are also potentially important to science.

While there are a few other places where corals grow on red mangrove trees’ prop roots, nowhere else in the Caribbean are so many different hard coral species known to grow on and among mangroves. The Hurricane Hole corals weren’t studied intensively until after the widespread coral die-off of 2005 to 2007, when prolonged high water temperatures caused coral bleaching, followed by coral death from diseases across the northeastern Caribbean. But many of Hurricane Hole’s slow-growing boulder corals are so large that they obviously survived that episode, scientists have concluded.

Coral colonies usually need sunlight and clear, seawater, with very little sediment and few temperature extremes. Water temperatures in Hurricane Hole are often either hotter or colder than on coral reefs in nearby open waters. But Rogers and other experts hypothesize that several factors may combine to allow corals to grow in this unusual setting, including the lack of a freshwater stream carrying sediment into the bays, and the shading from intense sunlight that the mangroves provide. In these conditions, repeated exposure to temperature extremes may have actually helped the corals evolve greater resilience.

Rogers’ studies of the site have yielded peer-reviewed scientific publications and her work there has been featured in Science and National Geographic.  Before the storm, she and other experts thought the Hurricane Hole corals might be a source of larvae for new coral colonies that can withstand changing sea conditions, which are predicted to be hotter and more acidic as the climate changes.

Marine life in the mangroves of Hurricane Hole, St. John, U.S. Virgin Islands
Scientists think red mangrove trees’ shade protects the Hurricane Hole corals from intense sunlight. Photo: Caroline Rogers, USGS, 2009

Now there are new questions to answer. Among them: Did Hurricane Irma’s storm surge damage the Hurricane Hole corals? Have they been affected by boat groundings, fuel spills, or the loss of the mangroves’ protection? How will they respond to a sudden, profound change in their environment?  Rogers has not been able to document the effects of the two hurricanes on this unique community.

“Hurricane Irma devastated St. John, leaving the island almost unrecognizable,” Rogers wrote in late September. “When it was safe to go outside, I saw a transformed landscape. Everything had turned from lush green to brown and gray. No leaves were visible. The island looked scorched.

“It seemed a miracle that my wooden house still had a roof,” Rogers wrote, “although one large window had exploded, another one had imploded, and some doors had ripped off.

“My office had been boarded up with aluminum hurricane panels. Those didn’t fail. They were intact, but the roof was ripped off, and the walls imploded. My government computer was ruined as far as I know.”

The area had no power, no running water, no internet, and no cell phone service. It took Rogers about four days to get a phone call out to tell friends, family and her USGS colleagues that she was uninjured.

“Cell service was limited to one hot spot in Cruz Bay, about a 40-minute drive from my house in Coral Bay,” Rogers wrote. “People gathered there every day, moving their cell phones around, hoping to get a signal. After hurricanes, cell phones are not very useful except as cameras. They can’t receive or make calls, they can’t get on the internet and they can’t be charged easily. Satellite phones would be better.”

Facing hardships that are difficult for anyone who hasn’t survived a major disaster to fathom, Rogers found that simple tools are most useful. A battery-powered AM-FM radio that can be recharged by hand-cranking or solar power is a more reliable source of news than a laptop, which is useless without power and an internet connection. A headlamp is better than a flashlight, “because you need both hands to carry your buckets of water.” Peanut butter sandwiches provide a quick burst of energy for a minimum effort, and a portable, solar-heated camping shower becomes a sought-after luxury.

Preparations that might seem over-the-top for a lesser storm turn out to be important for a Category 5 hurricane, Rogers learned. For example, the islanders are sometimes advised to stockpile a month’s worth of food and water at the start of hurricane season. Longtime residents “would say, ‘Oh, that’s ridiculous. You don’t need a month’s worth of food.’ Well, it turns out after a Category Five hurricane, you do.”

Because most islanders had no way to get news from the outside world, Rogers and her neighbors didn’t know that in the Eastern Caribbean, Hurricane Jose was growing from a Category One to a Category Four hurricane two days after Irma. But it was obvious St. John’s recovery process would take months. Four days after Irma’s landfall, friends persuaded Rogers to go to the U.S. mainland, since “people with chainsaws are more useful than PhDs during these disasters, and there was little I could do to help.”

Beached boats and bare trees in Hurricane Hole
Boat owners sought protection for their vessels in sheltered Hurricane Hole, but Hurricane Irma sunk and beached many boats, likely damaging corals. Photo: Caroline Rogers, USGS, 2017

The nearest airport, on St. Thomas, was closed, so the only way out was on a 42’ dive/snorkel boat to St. Croix—a rough four-hour nighttime trip through lightning, thunder, and downpours of rain from what Rogers later learned were the outer bands of Hurricane Jose.

Rogers stayed on St. Croix at the home of National Park Service employee Zandy Hilis-Starr. To get an idea of how local reefs fared in Irma, the two women snorkeled over parts of Buck Island Reef National Monument and found minimal damage. They took underwater videos, including one showing some large colonies of reef-building elkhorn corals that came through the storm in good condition.

Rogers uploaded that video to YouTube, where scientists can use it as a baseline for assessing damage done by the next hurricane, Maria, which brought sustained hurricane force winds of 90 miles per hour to western St. Croix on the night of September 19-20, on its way to its landfall in Puerto Rico as a Category Four hurricane September 20.

“I got the last flight out of St. Croix on September 19, just as the first rain and wind bands of Maria arrived,” Rogers wrote. “I have been staying with friends (on the mainland) since then, hoping to return to St. John and St. Croix as soon as possible to assess damage from these hurricanes.”  Rogers later learned that Maria mostly spared St. John but brought heavy rains that undermined roads and caused landslides.

“People say our island looks like a war zone,” she said a few weeks after the storm. “As someone who has lived there for so long, it’s painful. As a biologist, I know that it’s not a war, it’s a natural disaster. The plants are adapted to it, and they’re going to come back. I hear that there are already some leaves coming back and some flowers blooming.”

Photographs taken after the hurricane show Hurricane Hole crammed with boats, many of them beached, capsized or swamped.  Rogers wants to know how the diverse communities of corals, anemones, sponges, fish and other organisms fared, and to collaborate with other scientists on studies examining whether and how they recover from the hurricane. From temporary quarters on the U.S. mainland, she has begun working on a research plan and lining up other interested experts, getting ready for a hoped-for next round of studies at Hurricane Hole and other reefs around St. John and St. Croix.

Get Our News

These items are in the RSS feed format (Really Simple Syndication) based on categories such as topics, locations, and more. You can install and RSS reader browser extension, software, or use a third-party service to receive immediate news updates depending on the feed that you have added. If you click the feed links below, they may look strange because they are simply XML code. An RSS reader can easily read this code and push out a notification to you when something new is posted to our site.