Red tide has unexpected consequence: Silence

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From dead dolphins and manatees to dumpsters full of dead fish, the sights of last year's disastrous red tide left a lasting impression on those affected. But what does it sound like?

Eckerd College Marine Science professor Shannon Gowans acoustically tracks dolphins in Tampa Bay. She knows what a thriving underwater ecosystem sounds like.

Under normal conditions, it's the chirping and clicking of silver perch spotted sea trout and snapping shrimp.

In 2005, the year of another intense red tide, her microphones picked up something different: Almost complete silence. 

"We had a student working on this and she called it an acoustic apocalypse," recalls Gowans

Gowans is particularly concerned about invertebrates, like snapping shrimp.

"A lot of those species form the basis of the food chain. We know that fish can die, but what are some of the long term effects?" she asked.

Gowans is unsure if the silence is a result of everything dying or if the organisms are just quiet due to stress from low oxygen levels.

Either way, the stillness gives her reason for concern.

"We need to think about those sub-lethal effects. Just because it doesn't kill the animals, doesn't mean it’s okay," says Gowans.

The revealing sounds of silence make 2019 an important year to keep our ears to the water.

"It will be really interesting to see what happens after this year, how long does it take that soundscape to come back?" she wondered.

Gowans says the ecosystem bounced back pretty well back in 2006, the year after the bad red tide. Hopefully, this year will be the same.

The concern then becomes the potential impact of devastating back-to-back red tide years, something the Bay Area has never seen.