Zebra Mussels

      The zebra mussels showed up in the summer of 2010 near Port Deposit, MD, a few miles from the mouth of the Susquehanna River. In the summer of 2011, someone found a single mussel nearby in the Sassafras River. It is believed that it is not the only mussel in the Sassafras River since for the last decade zebra mussels have been working themselves downstream. “Biologists in the Bay region have long been concerned about the arrival of the species, a native of the Caspian Sea, because of its ability to mushroom into huge populations, crowd out native mussel species and alter ecosystems"  (Blankenship 1).

      Because zebra mussels are a fresh water species, biologists believe that it is unlikely that they will gain a foothold in the Chesapeake Bay. But since these mussels can attach themselves to the bottom of boats, to motors, and trailers, they can be transported to waterways such as rivers, lakes, and reservoirs where they can thrive. In regards to mussels spreading in the Bay, biologists are concerned about the high river flows in the spring and summer reducing the salinity of the Bay which can result in the zebra mussels gaining strength there.

      “Named for the striped pattern of their shells, zebra mussels are thought to have arrived in the Great Lakes in 1988 in the ballast water holds of ships from Europe" (Blankenship 2). Their dense colonies can block water intake pipes and cause major problems for industrial and municipal water uses. Zebra mussels have been blamed for causing billions of dollars in damages nationwide.

      In 1991, these mussels arrived in the tidal basin of the Hudson River. One zebra mussel, while feeding on algae, can filter as much as a gallon of water per day. Their filtering can reduce the populations of some algae species and promote the increase of other algae species. They have caused the reduction in dissolved oxygen levels in the water faster than the oxygen levels could be replaced. Zebra mussels in some places, due to there large populations, have reduced the supply of food for fish causing a fall in the fish population. Native mussel populations have nearly been wiped out in some areas because of competition with zebra mussels.

      Fortunately for the Chesapeake Bay and its tributaries, zebra mussels are not widespread. But it is important that users of these waterways are educated about prevention measures to make sure that they do not unintentionally transport mussels from place to place.

      This story points out how zebra mussels can easily be transported from one waterway to another. They then can be transported by unsuspecting boaters and fishermen who may not know what to look for or the dangers that invasive species can present. That’s why it is important that there are regular educational programs directed to the public, especially to those who boat and fish in areas where invasive species are present or may be gaining a foothold. Only then we all can be knowledgeable about the impact that invasive species can have on the ecosystem.

                                                          Works Cited

Blankenship, Karl. Zebra Mussels slowly spreading into Chesapeake Tributaries.

      Chesapeake Bay Journal, December 2011. Web. 3 October 2012.