July 22, 2022
Transportation & Safety
In June 2021, a fisherman contracted Vibrio vulnificus while in the Poquoson River-lower Chesapeake Bay region of Virginia. He was fortunate to survive the pathogenic infection; he underwent 11 surgeries over a 20-day hospital stay to preserve his leg and prevent the bacteria from doing fatal damage. Having recovered, the fisherman submitted a comment to the National Ocean Service through the nowCOAST online service, which read in part: "The Vibrio bacteria is a very dangerous and lethal problem for fishermen in this area - how can NOAA do more to notify fishermen when Vibrio is at a dangerous level?"
He is justified in his concern for his fellow fishermen, and consumers of their catch. Vibrio species have undergone a global - though not uniform - expansion over the past few decades, reaching new areas of the world previously considered adverse for these organisms. The genus Vibrio includes more than 100 species that usually proliferate in warm and low salinity seawater. Twelve of those species have been identified to be pathogenic to humans. The typical methods of exposure are through the consumption of raw or undercooked seafood, and recreational seawater activity. The most common clinical manifestations of vibriosis are wound infections, gastroenteritis, and septicaemia - also known as blood poisoning. Traditionally, the Gulf Coast has the most cases in the US, but the rise of sea water temperature at higher latitudes due to climate change is making the Northeast and Alaska regions two emerging hotspots for vibriosis risk. See this study performed by Regional Node Operations Manager Dr. Joaquin Trinanes for more on the future of vibrio population growth with warming waters.
Although the bacteria themselves cannot be observed by satellites, there are methods of estimating Vibrio risk using environmental observations from satellites. The NOAA CoastWatch Caribbean and Gulf of Mexico regional node at the Atlantic Oceanographic and Meteorological Laboratory (AOML, in NOAA's Office of Ocean and Atmospheric Research) has participated in the development and implementation of a model that provides Vibrio habitat suitability index on a global scale, using temperature and salinity as primary inputs. These fields provide a synoptic and continuous record of the environment conditions behind pathogenic Vibrio infections in coastal areas. The index is routinely being used by the European Centre for Disease Prevention and Control (ECDC) to monitor the Vibrio conditions in the Baltic Sea and improve the informed decision-making process, and is also being used to assess the changes in suitability for pathogenic Vibrio outbreaks in the annual reports of “The Lancet Countdown on Health and Climate Change”.(link is external) CoastWatch provides retrospective, current and short-term forecasts of environmental suitability for the entire globe, with special interest in coastal regions where human exposure is more likely to occur. The data can be visualized and downloaded using the Ocean Viewer tool here.
Current efforts are focused on improving the exposure model to create a new generation of early warning systems to identify and forecast areas and periods at risk, and on using climate, population and socioeconomic projections to generate more realistic estimates of past, present and future changes in Vibrio suitability and population at risk of vibriosis. More information on the development of scientific understanding of Vibrio can be found here on the AOML website.