A blue-green algae bloom is forming in the Gulf near Sanibel.
Research scientist Rick Bartleson of the Sanibel-Captiva Conservation Foundation said blooms are formed with the help of dust that is carried from Africa into the Gulf. “The dust can settle out in the Gulf and spur a bloom,” said Bartleson.
When blue-green algae comes near the shore, the algae turns brown. Locals noticed a change in water color and notified the foundation last week. Researchers from the foundation tested water near the Sanibel boat ramp on Monday, where they found a high concentration of the algae. Bartleson said they found, in particular, a type of algae called trichodesmiumerythraeum.
He said trichodesmium is an important part of the ocean ecosystem.
“One of the main algae in the ocean is probably trichodesmium and it fixes a lot of the carbon the ocean produces,” said Bartleson. “And produces a lot of the oxygen in the atmosphere.”
He said most researchers don’t consider this algae harmful, but swimmers should keep their distance around large blooms. And stay upwind. The smell is enough to want to keep clear. “The fumes from it are very noticeable and I wouldn’t breathe the fumes,” Bartleson said “It irritated- burned my throat after I was sampling it for a while.”
The waters may also turn from brown to red. Bartleson said since 1998, every time red tide has bloomed on the west coast, a blue-green algae bloom preceded it. Like the Africa dust, blue-green algae makes conditions more suitable for a red tide bloom by offering nutrients.
“[Blue-green algae] can provide up to 40 percent of the growth demands of a pretty dense bloom of red tide,” Bartleson said.The bloom will disappear when winds or the tide push it away.