Isle Royale ferry solves

ballast water treatment problem

The first permanent ballast water treatment system on a Great Lakes freshwater ship was installed on the M/V Ranger III, which ferries visitors from Houghton, Michigan, to Isle Royale National Park. The treatment system will keep the ship from transporting invasive species between Isle Royale and the port at Houghton.


Ocean freighters have imported 58 aquatic invasive species to the Great Lakes since 1959, when the St. Lawrence Seaway gave ocean ships access to the lakes. Zebra mussels and other invaders that snuck into the Great Lakes in the ballast water tanks of ocean freighters have caused billions of dollars in damage and triggered profound, undesirable changes in the lakes’ ecosystems. Discovered in the 1980s, the problem of ships transporting invasive species around the world in ballast water tanks spurred international efforts to solve the problem. While the U.S. government was developing ballast water treatment standards, officials at Isle Royale National Park worked with scientists at Michigan Technological University and Hyde Marine to develop their own solution. They developed a system that disinfected ballast water in the Ranger III’s tanks. “The installation of the ballast treatment system on the Ranger III is a milestone in Great Lakes protection history,” said Isle Royale National Park Superintendent Phyllis Green. “We are pleased to dedicate the first permanent ballast treatment installation on a freshwater ship in the Great Lakes.” The treatment system, which uses ultraviolet light and filters to kill organisms in the ballast water, will prevent the Ranger III from transporting invasive species between the port in Houghton and the port on Isle Royale.

Resource Challenges Addressed

  • Spread of invasive species


A sunrise on Lake Superior

Lake Superior, pictured here, will benefit from the ballast water treatment technology installed aboard a ferry that is frequently used on the lake. Credit: Courtney Celley U.S. Fish and Wildlife Service.

Results and Accomplishments

The ballast water treatment system will prevent the M/V Ranger III from transporting aquatic species between Isle Royale and the port at Houghton, Michigan. Currently, there are invasive species in Houghton that have not yet invaded Isle Royale, and vice-versa.