Options for Nonindigenous Species Control and Their Economic Impact on the Great Lakes and St. Lawrence Seaway: A Survey

Abstract

Nonindigenous species (NIS) cause substantial economic and ecological problems in the United States and other countries with marine trade. Current legislation and regulations require mandatory ballast water exchange for those ships entering the Great Lakes. Due to the low compliance rate, and some inherent defects of legislation, the current status of NIS control is not very encouraging. Several technical and legislative options have been proposed to improve the efficiency of NIS control. The most promising methods include filtration with ultraviolet, heat, and ballast water exchange. No one method, however, can 100% effectively solve the NIS problem. Moreover, the mandatory requirements may induce modal shifts from marine to rail or truck mode on the Great Lakes, which may cause several adverse side effects on the economy and the environment. The decision problems for the cargo owners and the legislative body are also formulated.