Two scientists with the National Oceanic and Atmospheric Administration recently visited St. Croix to better understand and protect coral reefs around the island. Long-term evaluation of the reefs has revealed both their beauty and the vulnerabilities they face.
The NOAA scientists who visited St. Croix from Miami included Ian Enochs, Ph.D., head of NOAA’s Coral Program at the Atlantic Oceanographic and Meteorological Laboratory (AOML), and oceanographer Nicole Besemer, the Caribbean Climate Operations Coordinator for the National Coral Reef Monitoring Program (NCRMP).
During their time on St. Croix, the researchers continued reef monitoring efforts and shared insights into what drew them to this field and why the island plays such a vital role in advancing coral reef science.
Researchers’ Backgrounds
Both Enochs and Besemer have been captivated by the marine sciences for many years, a passion that ultimately led them to their current positions at NOAA’s AOML and NCRMP.
“I have always been interested in coral reefs, even as a kid growing up in the U.S. Midwest who had never seen the ocean,” Enochs said. “At that time, I was more focused on their beauty and discovery. However, as I have grown to understand their importance and have experienced firsthand the challenges they face, I have become focused on how we can better understand and save the reefs before it is too late.”
Enochs emphasized the importance of NOAA’s work to protect reefs.
“NOAA recognizes the incredible economic and societal value of coral reefs, including the billions of dollars in tourism and fisheries they support for the U.S. economy, as well as the coastal and storm protection they provide to homes and communities,” he explained. “Our work is targeted at making sure that our American reef infrastructure is maintained for all that benefit from it.”
Besemer told the Source that her interest in marine life began at an early age.
“My spark for the marine science field started with going fishing with my dad as a child,” Besemer said. “My passion for coral reefs didn’t come until later in starting my career when I moved to South Florida shortly after my undergraduate studies and when I started to get more into scuba diving. I fell in love with being underwater and exploring local ecosystems. I worked on a variety of projects focusing on invasive species removal, water quality, sea turtle nesting, and seagrass habitat restoration. After experiencing these projects, I wanted to find my way back into diving.”
“I wanted to work in a position that would involve studying coral reefs to achieve my goals, and I am very fortunate to have the opportunities with AOML Coral Program to research coral reef habitats,” Besemer added.
St. Croix’s Coral Reefs
According to a NOAA report, the U.S. Virgin Islands are surrounded by a wide variety of coral reefs.
“Coral reefs are found around the three main islands of St. Croix, St. John, and St. Thomas as well as most offshore cays. Fringing reefs, deep reefs, wall and shelf-edge, patch reefs, and spur and groove formations are present on all three islands, although only St. Croix has well-developed barrier reefs. Bank reefs and scattered patch reefs with high coral diversity occur on geological features offshore at greater depths,” according to the report.
“St. Croix has coral growth along much of the insular shelf with a well-developed barrier reef on the eastern end and deep coral walls on the north shore.”
Enochs and Besemer shared details about St. Croix’s reefs and explained why they have long been a focus of NOAA research.
“St. Croix is home to beautiful coral reefs that support important fish populations and buffer the shore from wave energy, as well as provide amazing diving and snorkeling opportunities that bring in tourists and support local businesses,” Enochs said.
“Anyone flying into or out of St. Croix can immediately see the importance of reefs from the air, as waves break on them instead of pummeling into the shoreline,” he added. “Anyone walking through the towns can see the importance of diving and ocean tourism, and anyone that is lucky enough to actually see the reefs themselves underwater can view their beauty. Reefs are such a vital part of what makes St. Croix what it is.”
Monitoring the Reefs
Enochs explained that his work on St. Croix began more than a decade ago during a NOAA coral research project at Salt River Bay. Since then, the effort has expanded to include monitoring coral reefs around the entire island.
“I started working in the area over 10 years ago as part of NOAA’s monitoring program in Salt River. Since, we have collaborated with the National Park Service and the University of the Virgin Islands and worked to expand monitoring of St. Croix’s reefs to include multiple sites on each side of the island,” Enochs stated.
“We monitor coral cover reef structure that provides homes to diverse fish and invertebrates as well as water chemistry and temperature. I am fortunate to lead a team of some of the most passionate and brilliant scientists working on coral reefs today,” he continued.
Besemer further explained the methods NOAA uses to monitor coral reefs on St. Croix. She noted that the program is designed not only to track coral growth, but also to measure signs of decline, such as when erosion from fish, urchins, and sponges outpaces the reef’s ability to build new structure.
“Our monitoring program was set up to have comparable methods across jurisdictions that we visit. We deploy temperature recorders that record high precision temperature at a depth gradient around the island,” Besemer said. “We also deploy Bioerosion Monitoring Units to monitor bioerosion and Calcification Accretion Units to monitor calcification. We have six long-term transects in Salt River Bay, where we collect photomosaics to track community changes over time as well as Carbonate Budget Surveys.
“These surveys incorporate rates of coral production that build the reefs as well as quantifying the eroders, such as parrotfish, urchins, and sponges, that degrade the reef to determine if reefs are either growing or eroding,” Besemer continued.
Coral Reef Vulnerabilities
Among the major vulnerabilities to coral reefs are bleaching events and disease.
NOAA explains coral bleaching. “When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.”
Regarding coral diseases, NOAA stated, “A disease is any deviation from, or interruption of, the normal structure or function of any body part, organ, or system that has a distinct group of observable symptoms whose cause(s) may be known or unknown. Coral diseases are often observed as either color change or skeletal damage and may be accompanied by tissue loss.
Coral diseases generally occur in response to biological stressors, such as bacteria, fungi, algae, and viruses, as well as non-biological stressors, like increased water temperatures, ultraviolet radiation, and pollutants. One type of stress may exacerbate another.”
Enochs acknowledged the seriousness of the dangers threatening coral reefs.
“The scale of the coral reef problem is huge, and the number of challenges they face is large,” Enochs asserted. “As such, our response is multifaceted, and our expertise is broad. We conduct important monitoring operations like NCRMP, but also advanced laboratory-based experiments, detailed molecular and physiological studies, computer modeling, and even technological development. Our team is made up of coral scientists, software and hardware engineers, technicians and students, and we all work together to protect our reefs.”
Besemer noted that she has personally witnessed the losses caused by bleaching and coral disease.
“My first time at the monitoring sites was in 2019, and we have now visited in 2022 and 2025,” Besemer said. “I have seen firsthand the difference and amount of coral that we have lost due to bleaching and coral disease in our photomosaics. It’s very important to track these changes and make sure managers, stakeholders and the general public are aware of the status of their reefs so informed decisions can be made to protect and restore them,” she added.
The Future of St. Croix’s Reefs
As their work in St. Croix continues, both scientists emphasized that while monitoring is vital, it is equally important to use the data collected to guide protection and restoration efforts. Enochs noted that diving on the island’s reefs highlights both the urgency of the challenges and the reasons for hope.
“NOAA’s National Coral Reef Monitoring Program spans the Caribbean, western Atlantic, and the Pacific, holistically monitoring the health of U.S. coral reefs,” Enochs explained. “With the data we are collecting, we can identify areas that are particularly vulnerable and in need of attention, as well as resilience areas that we should be looking to for answers about persistence and restoration.”
“Diving in Saint Croix, I’m struck not just by the importance and beauty of the coral reefs, but also by the seriousness of the issues they face. In some areas, there has been so much coral death from bleaching and disease. Swimming for hundreds of feet past the skeletons of dead corals really puts things in perspective for me in terms of how much has already been lost. But it’s not too late. There’s still so much we can do,” Enochs emphasized.
He closed his remarks with a message of optimism about the future of reef protection.
“In the last 10 years I have seen a recognition by people around the globe that reefs are dying and a willingness to start doing something about it,” Enochs acknowledged. “The initiation of nation-wide monitoring programs like NCRMP and the beginning of large-scale restoration efforts such as NOAA’s Mission Iconic Reefs give me hope as we start to face these massive challenges head-on,” he concluded.
