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MIAMI (CBSMiami) – Large numbers of fish, turtles and other marine life are getting sick and dying along Florida’s Southwest coast where there are high concentrations of toxic red tide algae.

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Crews on Florida’s Sanibel Island shoveled up and bagged dead fish Thursday as southwest Florida deals with one of the longest red tide outbreaks in years.

Red tide is a naturally-occurring toxic algae that often occurs along florida’s gulf coast. Higher than normal concentrations are called blooms and the toxins in them can kill fish, crabs, and other marine life.

Florida Fish and Wildlife officials have been trying to save as many sea turtles as they can.

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They say nearly 300 sea turtles have died since the toxic bloom began in the fall, that’s about double the average number.

The harmful algae bloom has also been hurting businesses in the area.

Health experts say red tide can cause illness in people with severe respiratory conditions.

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Florida Fish and Wildlife officials say controlling the red tide is complicated. The harmful effects are caused by toxins that are released when the organism dies, so killing the algae would produce even more toxins in the water.