Zebra Mussel Invasion of the Great Lakes.pptVIP

Zebra Mussel Invasion of the Great Lakes By Leslie Zaikis, Rachel Sullivan and Heather Chirco Finger-nail sized mussels Native to Asia Recently brought to North America from Europe First found in Lake St. Clair Invasion has had many effects Presentation Overview What is a zebra mussel? History of the Invasion Positive Effects Negative Effects Methods of Control Future What is a zebra mussel? Dreissena polymorpha Striped shell pattern Size of a thumb-nail Attach to almost any hard surface Temperate, freshwater species Found 2-7 meters deep What is a zebra mussel? Extraordinary ability to reproduce Can lay over 1 million eggs in a season Spawning catalyzed by temperature and food Natural biofilters Have the ability to remove excess algae and restore bodies of water 1 zebra mussel can filter 1 liter of water per day However, tissues absorb contaminants in the water History of the Invasion Originally from the Caspian and Black Seas in Asia Brought from Europe from Ballast Water in ships First spotted in Lake St. Clair between 1986 and 1988 History of the Invasion Positive Effects Clear water by filtering algae Increases growth of aquatic plants Increase lake floor biodiversity Create a new food source for many native fish, birds, and other animals Monitor water contamination levels Negative Effects Clog water-intake pipes expensive to remove Negatively affect tourism Cut swimmers’ feet Alter taste of drinking water Negative Effects Reduce energy available in the food web Reduce many native fish populations Caused the near extinction of some native clam species Methods of Control Most scientists believe total eradication is impossible Most popular and effective = chlorine treatments Harms the surrounding environment Extensive cleanup efforts required Can form dangerous carcinogens Methods of Control Other chemical molluscicides Trace amounts of potassium Also very dangerous to surrounding species Often more toxic to fish than mussels Natural Predat