Habitat Restoration in Thunder Bay, Lake Huron

view of barge used for reef construction, with capped CKD pile on shoreline in the background

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Reef Construction

barge crane adding material to a reef during constructiondiver inspecting newly constructed reefbarge used for reef construction in Thunder Bay
Construction details:

Limestone cobble varying in size from 6 to 18 inches (donated by Lafarge) was used to build the reefs. Reefs are located adjacent to the Cement Plant reef and CKD reef; sites where spawning lake trout congregate. The East Reef serves as a reference site and will not be altered.  Different reef configurations allow evaluation of height, size, and orientation as factors that affect spawning and egg survival.Schematic diagram of reef construction

Stage I
– Eight small ‘pilot’ artificial reefs were built in 2010 to begin evaluation of spawning activity.
     • each reef is 30 feet in diameter by 9 feet high.
     • Monitoring wells were installed in six reefs to measure water quality within the reef structure

 Stage II – Construction of functional prototype reefs was completed in summer, 2011 
     • 24 reefs, 8’ wide, 75’ long.
     • reefs are either 5' or 10' high, oriented either NW-SE or  NE-SW  
     • one large reef, 300’ long, was added
                                                          Schematic diagram of reef construction
                                                                                                                                    (click on image for detailed view)

Map of Thunder Bay and Reef Locations
zoom in or out using the +/-  in the top left corner; click on reef icons for coordinates, reef depths, and photographs

View Thunder Bay Reef Map in a larger map