Testing the black muck Ian left behind in flooded homes

Ian left behind a lot of destruction but in the homes where floodwaters reached, it also left behind black muck.

Many worry whether they are risking their health by cleaning up.

WINK News carefully sampled some of the cakey stormwater gook and analyzed it at the FGCU Water School.

As the storm surge subsided, it left its mark in homes, pools and yards.

Floodwater from the Caloosahatchee carried who knows what into Holley Rauen’s home.

“I mucked out all of this with buckets and shovels,” Rauen said. “There were tree branches and leaves all with dead fish and mud in here.”

Homeowners along the river are still bailing out.

With questions about goo bubbling over, everyone is curious to know what the thick sludge might be hiding.

FGCU Water School expert Barry Rosen tested the sample.

After wetting the dry mud, he dabbed some on a slide and put it under the microscope.

“Here’s our muck, so there’s some big pieces like this. And I can tell by looking at this that this is part of a plant,” Rosen said.

What interested Rosen most is the wide variety of diatoms.

“What is the diatom’s function,” Rosen said. “They are the base of the foodweb for the little animals, the invertebrates that eat them, and then the fish eat the invertebrates.”

Scanning the samples found harmless diatoms from both fresh and salt water. There are different sizes and types, mixed in with small amounts of bacteria.

“That could be a bacteria, that could be a bacteria,” he said.

The microscope can’t break down the type of bacteria. There is potentially deadly Vibrio vulnificus present in salty water, but a good sign is what we didn’t see in the sludge.

“Not seeing any cyanobacteria, not really seeing any green algae either for that matter,” Rosen said.

There was a lot of sand and organic plant material, some traces of glass along with microalgae diatoms.

Nothing extreme or worrisome.

“Nothing from an organism standpoint that tells me that there’s something bad going on here,” Rosen said. “There’s a fair number of marine organisms, marine. There’s one potential green algae, it’s hard to say it’s a little washed out. But the fact that it is there, people are worried about a bloom. There’s no source organisms, at least not here in the sediments.”

These small samples show pretty much what you’d expect in the river this time of year, but it’s prudent to avoid direct exposure because this doesn’t belong in your home or on your skin.

Rosen said he’ll be interested in seeing whether Ian’s stormwater creates a larger outbreak of blue-green algae in the spring.

What could happen because of the co-mingling of salt and fresh water is it will likely kill off plans allow algae to flourish.