Up until now, it was believed that the invasive Zebra Mussels had not spread beyond the Susquehanna Flats, but recent monitoring has confirmed their presence farther south. Zebra Mussels cannot survive in waters with high salinity levels, but it has been suggested that higher than average rainfall in the late spring has led to lower than average salinity in the upper and middle Chesapeake. This could potentially explain the presence of these mussels in a habitat where they could not previously survive in. Photo courtesy of the Chesapeake Bay Program From the MD DNR: "The Maryland Department of Natural Resources (DNR) recently confirmed the presence of zebra mussels (Dreissena polymporha) in tributaries of the upper Western Shore near Middle River in Baltimore County.  On August 17, 2015, a waterman alerted DNR Biologist Brenda Davis of small zebra mussels fouling their crab gear off the Gunpowder, Bush and Middle Rivers. The next day, DNR Fisheries Habitat and Ecosystem Program biologists found numerous mussels in aquatic vegetation while trawling Middle River. 'Zebra mussels are an aggressive invasive species and reproduce at a very prolific rate, outcompeting native species for needed resources,” said Matt Ashton, a DNR biologist and mussel expert. “These mussels quickly overtake and cover all available areas to such an extent that they can clog water intake structures, boats, moorings, ropes, fishing lines, traps, and even dams and power plants. Their migration further south toward Baltimore may pose a serious economic and environmental threat to the bay and its inhabitants.'" The DNR asks for the public to report any suspected sightings of Zebra Mussels to [email protected]. The DNR also asks for boaters to follow these simple precautions that have been proven to help prevent the spread of this invasive species:
  • Remove all aquatic plants and mud from boats, motors and trailers; and put the debris in trash containers.
  • Drain river water from boat motors, bilges, live wells, bait buckets, and coolers before leaving to prevent these aquatic hitchhikers from riding along.
  • Dispose of unused live bait on shore, far from the river or Bay, or in trash containers.
  • Rinse boats, motors, trailers, live wells, bait buckets, coolers, and scuba gear with high pressure or hot water between trips to different water bodies.
  • Dry everything for at least two days, and preferably five days, between outings.
  • Limit boating from place to place ─ particularly between the Susquehanna and Middle River to other water bodies in Maryland ─ where zebra mussels haven’t invaded.
More information on Zebra mussels can be found on the DNR's website or at the Chesapeake Bay Program's site.