Climate Change at Isle Royale: SS America Shipwreck

The America is a popular sight on the west end of Isle Royale. Well preserved due to Lake Superior’s cold waters, the shallow shipwreck is easy to view on calm days.

In 1928, the ship’s ill-fated last journey ended at North Gap near Washington Harbor as the First Mate made a navigation error and ran onto a rock reef. Despite the sad loss of a popular ship, no people perished during the rescue. Today, the America shipwreck is protected as part of the park, and is a common stop for both divers and boaters.

Despite being located so close to the surface, Lake Superior still preserves the America shipwreck.

Paul Brown

Climate Concerns

Zebra Mussels

The pristine nature of the America shipwreck is threatened by the expansion of zebra mussels, an invasive species that attaches to and quickly envelopes underwater features. These shellfish arrived in the Great Lakes in the 1980s, but have been held largely at bay by Lake Superior’s cold water temperatures. Eventually, warmer waters will allow the zebra mussel to reproduce more easily, and therefore threaten the visibility of the America. The expansion of zebra mussels could also degrade Isle Royale’s nine other shipwrecks.

Ice Formation

While Lake Superior preserves Isle Royale’s shipwrecks, certain conditions also pose a threat. Warmer water temperatures increase evaporation rates, generating stronger storms and producing unstable ice cover in the winter. Ice sheets that don’t freeze solid easily move with wave activity – especially when strong storm surges are becoming more common with climate change. Loose ice can damage shipwrecks, and the America is particularly vulnerable due to its shallow position.

Bottom Line

Shipwrecks are tangible connections to the rich maritime and human history of Isle Royale. As the climate changes, the America and the nine other notable shipwrecks within park waters are threatened by increasing populations of zebra mussels and damages sustained by unstable ice floats.

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