The Thunder Bay National Marine Sanctuary encompasses 448 square miles (1,160 square kilometers) of northwest Lake Huron, off the northeast coast of Michigan's Lower Peninsula. It is the 13th national marine sanctuary in a system that extends from American Samoa to Massachusetts.

The sanctuary is also used to gauge the Great Lakes' health. Diving archaeologists have noticed how one well-known invasive species — zebra mussels — have spread across the region.

"The mussels cover just about every surface of the shipwrecks in Thunder Bay," said maritime archeologist Russ Green of NOAA during a recent live webcast.

"It's very dramatic, it complicates archeology, but the real story is what [the invaders have] done to the fish stocks in the Great Lakes," Green said. "They filter out food that the smallest fish in the Great Lakes need to survive."

Built in 1856, The F.T. Barney, pictured above, departed Cleveland on Oct. 19, 1868 when it was struck by the schooner Tracy J. Bronson.

Shipwreck Alley's Sunken Treasures