Modeling invasive activity: Zebra mussels' infiltration of North American rivers
The invasion of nonnative species has widespread and detrimental effects on both local and global ecosystems. These intruders often spread and multiply prolifically, overtake and displace native species, alter the intended interactions between flora and fauna, and damage the environment and economy. A particularly pesky invader is the zebra mussel (Dreissena polymorpha). Given its abundancy, fecundity, and heartiness, zebra mussels frequently outcompete native bivalves. Their dominance interrupts the natural cycle of nutrients and disrupts the structure and function of infested waterworks. These so-called "ecosystem engineers" generate substantial removal costs for individuals, corporations, and towns; estimates indicate that zebra mussels cause $1 billion in damages and control costs every year.