Virtual Field Trip to the Florida Keys

Upper Keys: Location 5 - Long Key

Long Key State Park. Close up of the muddy tidal creek.

Here, the surface of the mud flat is covered by a microbial (probably cyanobacterial) mat. The sticky filaments of the mat trap fine-grained sediment, so that eventually the mat becomes covered with sediment. This prevents it from photosynthesizing, so to survive, the mat must grow through the sediment which covers it.

The mat in the photo has been split or torn, possibly by drying out and/or current activity.