Native clams seem to have been protected from zebra mussel infestation at Metzger Marsh by the interaction between warm temperatures and soft sediments. Warm water encourages burrowing, but soft sediments are required to allow encrusted clams to burrow. In support of this conclusion, we have since found live unionids or fresh shells at three other Lake Erie wetlands.
Nichols, S. Jerrine and Wilcox, Douglas A., "Burrowing Saves Lake Erie Clams" (1997). Environmental Science and Ecology Faculty Publications. 37.