The blobs found from Virginia to Long Island, N.Y., have been reported by witnesses as being of "various sizes," with the smallest "around the size of a baseball," with a texture ranging from "kind of rubbery or leathery" to "kind of soft," a release from the Virginia Institute of Marine Science at the College of William and Mary said Thursday.
VIMS Professor Emmett Duffy has a simple explanation for the mysterious objects.
"They're potato sponges," Duffy says, normally inconspicuous animals that inhabit shallow coastal habitats around the world, attached to the seafloor with a network of protein fibers and glassy, needle-like "spicules" that form something like an anchor.
Large waves and strong currents -- such as those produced by a hurricane -- can dislodge large numbers of the sponges, freeing them to float to the surface and wash ashore.
Clogged with storm debris and no longer able to filter feed, the sponges eventually die, Duffy said.
Potato sponges are not poisonous, but VIMS scientists caution people to avoid touching.