UNH Researchers Developing Algorithm to Predict Seafood Contamination in NH's Great Bay Estuary

In response to a bacterium that is increasingly becoming a public health concern, scientists at the University of New Hampshire (UNH) are putting all of their efforts into creating an algorithm that will allow researchers to successfully predict when New Hampshire’s Great Bay Estuary’s oysters may be at risk of contamination. (The Little Bay area of the estuary is home to more than a dozen oyster farms that supply oysters to local restaurants.)

The aforementioned bacterium is Vibrio parahaemolyticus, a gram-negative bacterium that is found around the world in coastal environments. It is the most common source of seafood-borne illness in the United States, with 45,000 cases of infection reported annually.

Food-borne illnesses associated with the bacterium are increasing across the nation. According to a recent study, published in PLOS One, Massachusetts and Connecticut combined reported 5 cases of infection with this bacterium in 2000; however, in 2013, the case count grew to 147 reported cases.

As a means to address this growing public health concern, researchers put their efforts into conducting a study with two main objectives: increasing knowledge pertaining to the link between this bacterium and any associated environmental factors, and using that information to inform the development of an algorithm that will allow researchers to estimate the presence of V. parahaemolyticus in the Great Bay Estuary’s oysters.

In a press release on the study, research associate professor of natural resources at UNH, and one of the scientists involved in the study, Stephen Jones, PhD, explained, “This research represents a significant advance in our understanding of what environmental conditions are related to the incidence of V. parahaemolyticus, a human pathogenic bacterium, in New Hampshire oysters. We found that not only water temperature and salinity are important, but also chlorophyll, which is a measure of how much phytoplankton biomass is present in the water overlying natural oyster beds.”

Researchers at UNH have been following Vibrios bacteria in the Great Bay Estuary since the 1980s, with consecutive annual study occurring for the past 10 years, and they have made major discoveries throughout their studies. UNH researchers were the first to find Vibrio vulnificus in the Great Bay Estuary in the 1980s. Furthermore, just last year, they were able to create a method for distinguishing human illness-causing strains of Vibrios in New England oyster beds, a method that is currently undergoing the process of being patented. On the heels of these successes, the researchers used a “shellfish harvest area-sized study” to understand V. parahaemolticus in greater depth and to develop “risk forecasting tools for the region.”

According to Dr. Jones, “In the last five years, V. parahaemolticus has become an increasingly significant pathogen to humans who consume raw or undercooked shellfish in the Northeast United States. Where in the past cases of illness were quite rare, there have now been outbreaks of illness caused by this species in Long Island Sound and the southern Gulf of Maine in Massachusetts. In New Hampshire, there has yet to be a reported case of illness from this pathogen associated with shellfish consumption, but our collective studies at UNH are tracking how its presence is changing in New Hampshire coastal waters and shellfish.”

By incorporating abiotic and biotic-related predictors to estimate Vibrios incidence, the researchers are building off of past studies related to environmental-associated conditions. According to the study, “Robust forecasting of Vibrio presence, concentrations, and associated environmental conditions would greatly aid the management of shellfish harvesting for both preventing disease and maintaining a healthy shellfish industry.”