FRESHWATER PROBLEM The water shimmered in the afternoon sun The lake appeared cool and refreshing But a tiny creature was causing massive problems under the surface Zebra mussels covered rocks and plants Some zebra mussels even attached themselves to other mussels and crayfish Large numbers of zebra mussels often gather together in one area These groups are known as colonies 5 CHAPTER 1
Zebra mussels were causing trouble on land too Sharp shells from dead zebra mussels washed up on the sand People cut their feet on the shells As a result people stopped going to the beach People continued to fish on the lake But there were fewer and fewer fish Zebra mussels took away the fish’s food sources Some people also left boats in the water These boats became covered with zebra mussels The mussels ruined their motors Many lakes and rivers in the central United States have problems with zebra mussels And people worry about them entering more bodies of water These 6
Zebra mussels can attach to hard surfaces but freshwater mussels native to the United States cannot invasive animals often harm ecosystems Zebra mussels spread quickly through waterways They can even survive out of the water for up to 21 days The mussels find new areas to breed Then they live near shore and on lake beds 7
