In Georgia, Sea Grant and shrimpers hope new app will bring more data on black gill

By: Emily Woodward, Georgia Sea Grant

Georgia Sea Grant and the University of Georgia Skidaway Institute of Oceanography entered their fourth year of black gill research with the introduction of a new smartphone app that will allow shrimpers to help scientists collect data on the problem.

Black gill is a condition caused by a microscopic parasite that many Georgia shrimpers believe is responsible for their reduced harvest in recent years. Shrimp is Georgia's most economically viable fishery.

Captain Wynn Gale, a commercial fisherman from Darien, Ga., recalls seeing black gill back in the mid-1990s while shrimping with his dad.

“It gets worse and worse every year. We noticed black gill in our shrimp about five days into the season last year,” Gale said. “We had a triple whammy in 2016 with black gill, a tropical storm and then Hurricane Matthew that decimated the population and gave me one of the worst seasons I’ve ever had.”

Researchers Marc Frischer (UGA Skidaway Institute of Oceanography), Brian Fluech and Lisa Gentit (Georgia Sea Grant) examine shrimp for signs of black gill. Credit: UGA Skidaway Institute of Oceanography

With funding from Georgia Sea Grant, Marc Frischer, a professor of marine science at the UGA Skidaway Institute of Oceanography, has been collaborating with UGA Marine Extension and Georgia Sea Grant and the Georgia Department of Natural Resources’ Coastal Resources Division to explore possible causes and impacts of black gill.

So far, research has shown that black gill can impact a shrimp’s endurance making it more vulnerable to predators. Researchers also have observed incidents of direct mortality in shrimp with black gill, but Frischer acknowledges that there are many questions that science doesn’t have answers to yet.

“Black gill is a complex issue with many unknowns and there isn't going to be a single factor that explains it,” Frischer said.

The communication and cooperation between fishermen and government has increased dramatically since the beginning of the study, Frischer says. Tensions were high in 2013 when the study began. Shrimpers were angry and demanded that something be done to address the problem of black gill. Meanwhile, fishery managers were unclear if black gill was even causing a problem and frustrated that no one could provide them any reliable scientific advice. There was no research underway to explore the issue.

“In 2016, we still have black gill. The fishery is still in trouble, but it does feel like we are at least understanding a bit more about the issue,” Frischer said. “Most importantly, it is clear that all of us are now working together.

Researchers collect samples of shrimp with black gill to test in the lab. Credit: UGA Public Service and Outreach

Using the black gill smartphone application created by UGA associate professor of engineering Kyle Johnsen, shrimp boat captains and recreational shrimpers can now help document the extent of black gill throughout the shrimp season.

The fishermen will use the app to document their trawls and report their data to a central database. Using GPS and the camera on their smartphone, they will record the location and images of the shrimp catch, allowing the researchers to see what the shrimpers see. The ongoing data collection throughout the shrimp season will provide scientists a more detailed picture of the prevalence and distribution of black gill.

Recruiting, training and coordinating the shrimpers will be the responsibility of UGA Marine Extension and Georgia Sea Grant.  

“We’ll work with the shrimpers to test the app and see what changes should be made based on their feedback,” said Bryan Fluech, associate director of Marine Extension.  

“They are on the water almost daily and have a lot more eyes and ears than the researchers alone,” Fluech said. “Given the proper training, they can provide valuable and accurate input on the prevalence of black gill and the changes they’ve seen over time.”

Gale and other Georgia shrimpers are anxious to solve the problem. If the app leads to better understanding and management of black gill’s impacts, they’re willing to give it a try.

“We want to get the solution so we can continue with our profession,” Gayle said. “I will be contributing data as best I can at the start of shrimp season.”