About 50 inches of rain falls in Beaufort County each year.
And scientists want to know how that rain affects the more than 300 square miles of water in the county and the millions of shellfish that are harvested from it.
According to University of South Carolina Beaufort professor and researcher Eric Montie, the effects can be toxic.
“Rainfall leads to stormwater runoff, and stormwater runoff leads to three bad things that can happen,” said Montie, an assistant professor of biology in the school’s Department of Natural Sciences. “The three sort of big problems are the fresh water, chemical pollutants and biological pathogens it brings that can affect oyster beds and big fisheries.”
USCB and the S.C. Department of Natural Resources recently received a grant of about $300,000 to study the potential negative consequences of rainfall on five waterways in Beaufort county.
The school, which received $42,910 of the grant, will focus solely on the May River. DNR will monitor the Okatie River, Battery Creek and, likely, Wallace and Huspah creeks, according to DNR research coordinator John Leffler.
Leffler said those waterways were picked in consultation with Beaufort County to see which are most sensitive to runoff.
The grant — funded through a program with the National Oceanic and Atmospheric Administration — allows the researchers to look at the five watersheds simultaneously instead of just one a year, Leffler said.
USCB and DNR have purchased equipment that will be stationed at various spots throughout the waterways for a year. The devices, to be deployed in about a week, will let researchers measure rainfall amounts, water temperature, water salinity and chemicals, Montie said.
The study comes in the wake of a massive die-off of the county’s oyster population in recent weeks. Environmental officials and fishermen have said that as much as 75 to 90 percent of the oysters are dead.
They have attributed much of the mortality to heavy summer rain that inundated the estuaries with fresh water and lowered salinity. The Beaufort area has already received about 60 inches of rain through October — 10 inches more than the yearly average, according to WeatherDB’s database.
Larry Toomer, owner of the Bluffton Oyster Co. on the May River and recently elected Bluffton Town councilman, said he thinks the study is a great way to understand what is happening locally.Much of the county’s economy depends on the water through things like fishing and tourism, he said.
“Any type of science that we get done here in our backyard would be worth so much more than anything we’ve used from different areas,” he said. “The study here would be valuable, so the town and county would have one more thing to look at and one more way of preventing the total degrading of the river.”
Leffler and Montie said much of the runoff comes from the development in the county. The water picks up chemicals and bacteria as it runs over the developed areas, and there is less pervious surface area for it to be absorbed into the ground.
Beaufort County has already worked to put many controls in place, director of engineering and infrastructure Rob McFee said. However, the county is looking forward to the study to see what areas are most sensitive and how best to address them, he said.
“We have to do a good job balancing the desires of environmental protection but also balancing to make sure this area is friendly with developments,” McFee said. “We have to understand the system to the greatest extent possible so we can balance those often competing desires.”
Montie said he hopes the study will help find the best way to achieve that balance.
“We don’t want to affect the oysters and shrimp and blue crabs,” he said. “That is what’s going to take away from tourism and development, which is what is bringing people to the area.”