Artificial reefs boosting fish populations

in Lake Huron

Thirty artificial fish reefs were installed in Lake Huron’s Thunder Bay, creating new fish spawning habitat in an area that was damaged by cement kiln dust from a nearby factory.


Over the course of several decades, cement kiln dust from a nearby cement factory in Alpena, Mich., leached into Lake Huron. The cement kiln dust destroyed an area of fish spawning and rearing habitat that was used by lake trout, lake whitefish and other reef spawning fishes. In 2002, the cement kiln dust pile was capped and a retaining wall was constructed to prevent further cement kiln dust leaching. Six rock reefs were constructed in Thunder Bay in 2010 with limestone cobble donated by the Lafarge Cement Plant. Another 24 reefs were constructed during the summer of 2011, creating a total of two acres of new fish spawning habitat. Although the project was focused on lake trout, other reef-associated fishes — including lake whitefish, walleye and smallmouth bass — are expected to benefit from the new reefs.

Resource Challenges Addressed

  • Loss of fish spawning habitat for several native fish species


An excavator on a barge drops material into water to build an artificial reef

Artificial reefs, like the one being built here, help boost fish populations by providing a safe space to spawn. Credit: Michigan Sea Grant

Results and Accomplishments

Lake trout and whitefish are already spawning on the artificial reefs, which will increase fish populations in Thunder Bay and Lake Huron.