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An organism that has generated a toxic red tide in Florida waters since 2017, causing health issues in residents and killing thousands of sea life, is no longer being detected, the Florida Fish and Wildlife Conservation Commission said in a report.

The agency said Wednesday it collected water samples in southwest Florida, northwest Florida and along the East Coast of the state and did not find any traces of Karenia brevis, a microscopic alga that turns the color of the water red.

Red tides can last as little as a few weeks to longer than a year, according to the FWC. The current red tide devastating the region was first reported in November 2017.

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The red tide has washed up dead fish on the shore in Vero Beach, Florida, creating respiratory problems for humans. Edith Widder / ORCA Florida

"Many red tides produce toxic chemicals that can affect both marine organisms and humans," the agency said on its website.

The organism Karenia brevis produces brevetoxins that attack the central nervous system of fish, causing them to die. In August, then-Florida Gov. Rick Scott declared a state of emergency for seven counties after thousands of marine animals were killed due to the red tide.

In a statement, Scott said he wanted to "provide significant funding and resources to the communities experiencing red tide, so we can combat its terrible impacts."

The toxins released from the algae can also be harmful to people, the FWC said. When the toxins are breathed in, they constrict passages in the lungs, causing difficulty breathing and coughing.

Monet Sexaure, a resident of Siesta Key, a barrier island right in the path of the red tide, told NBC News in September that she was experiencing headaches and coughing and linked her symptoms to the toxic red tide.

“I thought I was coming down with a cold,” she said. “But I never got a cold.”

Sexaure said she contacted Florida’s Poison Control Centers and was told to wash her clothes frequently because the toxins can cling to fabric. Her doctor advised her to take medicine to relieve her symptoms.

The FWC said it will be releasing another report on the state's red tide Friday.