Published: Apr 11, 2012 9:37 PM EDT
Updated: Apr 11, 2012 11:19 PM EDT

LEE COUNTY, Fla. - Dan Dobson and his family are loading onto their boat at the W.P. Franklin Lock. They came from Michigan to spend the week fishing. But fisherman like Dobson are being asked to be aware before they approach the Caloosahatchee or any of its tributaries.

Health officials are giving a precautionary warning that algae bloom has been spotted in sporadic parts of the river. The dangerous bloom shut down the Franklin Lock last year. The green and pungent waters weren't safe for humans or pets.

"The greatest harm generally comes from ingestion," said Diane Holm with the Lee County Health Department, "also people with respiratory ailments may have some difficulties breathing around it." 

The threat of algae bloom is common for this time of year. During the dry season, the bloom generally forms in the fresh and brackish waters in Lee County. The rainy season will help to wash the bloom away.

Luckily, many of the warning signs for the potentially dangerous algae are obvious. Look for greenish or off-color water, or if the water smells different that could be a sign.

"And if you see dead animals or dead fish floating nearby, then those are probably unsafe signs that you want to avoid the area," said Holm.