Wildlife Management - Invasive Species

Invasive species pose a significant threat to the ecological balance of our national parks, and while the Upper Midwest grapples with many such species, Isle Royale remains relatively free from them due to the formidable barrier of three quadrillion gallons of cold Lake Superior water. However, despite this natural barrier, invaders do manage to infiltrate the island, particularly around developed areas, docks, trails, and campgrounds where exposure from the mainland is high. Even seemingly insignificant intruders like a single seed or zebra mussel, if left unchecked, can establish thriving populations, potentially leading to a decline in island biodiversity and compromising the integrity of its ecosystem. It is essential for visitors to take proactive measures before and during their trip to help thwart this invasion.

Mitigation efforts include intensive early detection, removal of invasive mussels from priority areas, and public education initiatives.

Attention visitors: It is crucial to safeguard the delicate ecosystem of Isle Royale by taking proactive measures against the proliferation of aquatic invasive species, notably the zebra mussel, which has been detected in Lake Superior. Before entering park waters, all boaters are required by law to thoroughly decontaminate their vessels to mitigate the spread of these invasive species. This entails draining live wells and bilge on land, removing transom water, lake water, and unwanted bait from boats, and washing them with hot water, high-pressure water, or disinfectant. Additionally, boaters must clean and dry their equipment, including bilge and gear, in the sun for five days, with rainy days excluded from the count. Canoeists and kayakers are advised to remove weeds, algae, and other plant and animal materials from their boats, wash them with hot water, high-pressure water, or disinfectant, and similarly clean and dry their equipment for five days in the sun. Anglers are urged to clean their fishing gear thoroughly before departing for the island. Divers should wash all dive gear in warm chlorinated tap water, disinfect wetsuits with special-purpose shampoo, and dry all equipment and wetsuits for seven days before island departure. Moreover, while on Isle Royale, canoeists, kayakers, and anglers must wipe down their boats and associated gear before transitioning from Lake Superior to inland waters. By diligently adhering to these guidelines, visitors can play a vital role in preserving the park's natural splendor and safeguarding its diverse wildlife.

A complete list of Isle Royale's current and historical native and invasive species currently lists 1361 unique species. https://www.nps.gov/isro/learn/nature/species-list.htm