His observation was based upon biological surveys in rivers and streams throughout Western Pennsylvania, fieldwork performed during a time of transition that garnered an irreplaceable collection of local mussel shells for the museum. Ortmann's work and warnings have also been under much discussion this week because 230 of his intellectual heirs from all over the United States and Canada are currently gathered at the Westin Convention Center Pittsburgh. The biologists who've been sharing current research findings during the annual meeting of the Freshwater Mollusk Conservation Society rely upon specific Latin and Greek names for mussels and snails rather than the colloquialisms so favored by Mr. Flood. They also make frequent reference to an ecosystem threat unknown in Ortmann's time, the continuing spread of Dreissena polymorpha or the zebra mussel - a tiny but prolific Caspian and Black Sea native that was introduced to the Great Lakes in 1985 via the ballast water of European tankers. Native mussels starve or suffocate where this striped invader becomes established.
Mussels are a waterway's natural filters.
Huge colonies of zebra mussels can now be found in sections of the Ohio River, but they have yet to cause problems in the Allegheny or Monongahela. According to Bob Anderson, a biologist with the U.S. Geological Survey, low calcium levels and a flow rate sufficient to continually flush out the foreign species' planktonic young seem to be the principal factors shielding both rivers. That's not just good news for recovering mussel species. It also means river-edge wanderers can still find objects of astonishing natural beauty amid the water willow thickets where muskrats habitually feed. All rights reserved.