MELBOURNE, Fla. -- A jelly-like algae lofting off Brevard, Flagler, and Volusia counties in recent weeks is causing respiratory irritation for some people along the beach and threatening shellfish and finfish.

The Fish and Wildlife Research Institute in St. Petersburg began receiving reports of discolored water along Volusia County's coastline in the last week of April. The institute identified samples from the bloom as the diatom algae, Thalassiosira.

Since April 29 the institute has received numerous reports of discolored, smelly water from Brevard, Flagler and Volusia counties. Samples from those three counties tested at high concentrations of Thalassiosira, Local 6 News partner Florida Today reported.

FWRI staff familiar with Karenia brevis, the algae that causes red tide, reported a brown, discolored water "slick," heavy with organic foam at Melbourne Beach. They also reported a "throat irritation, not like (Karenia brevis) red tide."

While biotoxins have not been associated with Thalassiosira, the blooms can cause shellfish and finfish deaths by clogging gills, starvation from decreased food quality and low oxygen in the water after the blooms.

Thalassiosira contains several species which form jelly-like colonies. Natural ocean processes help the blooms form. The gelatinous colonies of Thalassiosira can get caught up in the Gulf Stream and flow north along the Atlantic coast.

The last major diatom blooms to impact Florida occurred in 2002 off the coast of southwest Florida between Naples and Key West and in 2003 off of Pasco and Hernando counties.