Studying black gill in shrimp

SAVANNAH, Ga. (WTOC) - There are many challenges that Georgia’s shrimping industry faces, including the price of fuel and keeping up with regulations.

Over the last few years, scientists with the UGA Skidaway Institute of Oceanography have been studying another challenge called black gill.

It was a full day in Wassaw Sound on the Research Vessel Savannah for the Black Gill Stakeholders expedition. On board are scientists, shrimpers and DNR staff members taking a closer look at what black gill is. And what better way to do this than to do some shrimping at sea.

“We know what’s causing it. We think that what’s driving it is probably our changing climate particularly our warmer winters and we know it’s probably here to stay,” said Marc Frischer, a professor with the UGA Skidaway Institute of Oceanography.

Black gill is a parasite that scientists believe feeds on shrimp gill tissue. This feeding triggers an immune system response in the shrimp.

Finding out if a shrimp has black gill is actually easier than you might think. If this one has it you would see a black, almost sharpie-like color, right here on the side of its head. Something that’s really important for everyone to know is that it’s perfectly safe to eat. Really, the biggest concern is for the shrimp itself.

Scientists, like Frischer, say black gill could have a big impact on the overall shrimp population. If a shrimp has black gill, it makes it harder for them to breathe and therefore it can kill them directly or make them more likely to get eaten by predators.

Frischer says few shrimp will live through it, but it is possible.

“These shrimp are molting only about once every other week, so they have to live with this for those two weeks,” Frischer said.

Shrimp boat captain Wynn Gale refers to a bad run of black gill they saw a few years ago.

“It killed everything,” Gale said. “There was no shrimp.”

Luckily, Gale said it’s gotten a bit better.

“It isn’t nearly as prolific as it used to be,” Gale said.

But it’s still something shrimpers blame for reduced harvests.

Scientists say black gill never goes away. There are just times of the year when they don’t see symptoms of it.

Frischer says since 2016 they started seeing symptoms earlier, starting in June instead of August. It peaks in the fall and is few and far between by late December

Frischer says we’re blessed in Georgia to have an amazing shrimp product, but it’s fragile.

“When things are changing so rapidly and so unpredictably, we can’t get out here enough. We really need to keep our eyes on this problem. Right now, it’s black gill. I don’t know what it will be tomorrow, but it will be something,” Frischer said.

While scientists have learned a lot about black gill, Frischer says many mysteries remain.

Frischer did point out that he doesn’t believe there’s a chance shrimp will go extinct, but that there’s a chance that Georgia’s shrimp fishery could be depleted so they’re trying to prevent that.

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