Asian green mussels threat to oyster beds, nuisance for boaters

Just steps off of the city of Sebastian’s shoreline, a working waterfront keeps the town’s rich fishing history alive.

“Another day on the river sorting oysters,” Nicolette Mariano said.

Crews spend hours on the water shucking away to serve-up the only locally grown oysters you’ll find on the Treasure Coast.

Mariano started her Treasure Coast Shellfish business during the pandemic.

“It has been a complete rollercoaster,” she said.

Keeping her seed oysters under careful watch and tracking the time they’re in and out of the water, she monitors temperatures and water conditions all while working around fears of algae blooms or hurricanes.

And if those challenges aren’t enough, there’s also the threat of Asian green mussels.

“There’s a big mussel. Green mussel, you can see the byssal threads,” Mariano said. “I think you guys saw they found a couple little ones, too with what we were going through, so obviously [they] reproducing already this year.”

The green mussels, originally from the Indian and Pacific Oceans, compete with Mariano’s oysters for food, threatening their survival and taking away food for crabs and fish.

However, this isn’t just about Mariano’s bottom line, but this entire ecosystem.

“Like right now, if you look on the dock pilings, you don’t really see a lot of oyster beds,” she said. “That’s a native species. That’s a keystone species. So even just taking one or two of those green mussels out, it’s making an impact.”

Each oyster saved can filter 50 gallons of water a day.

Mariano is passionate about trying to get rid of invasive species, so she keeps an eye out for green mussels throughout her 7-acre farm.

“We were seeing a lot at some point last year, the little ones,” she said.

However, other parts of the state see it much worse, like in Tampa Bay, where the green mussels were first found in the state in 1999.

Likely released into the water by accident from large cargo ships, the mussels damage boats and even clog power plant intakes.

“They have the potential to wreak havoc out here for you,” Mariano said.

So, she disposes of what she does find, giving her oysters the best shot to make it to harvest and help this estuary thrive to keep the waterfront working.

“Got to take care of the environment, so it can take care of you,” Mariano said.

A lot of the pressure to help stop the spread of the green mussels is on boaters who should check the bottom of boats to make sure they’re not stuck and disposing of them if found.

Boaters taking their boat to a new place, or new body of water, should make sure to first drain bilge at a proper disposal station.

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