Non-native invasive species can be insidious, whether plant or animal, bird or fish, snail or mussel. They can wreak havoc in ecosystems by, among other things, supplanting the native species.
    In the Southwest, Tamarisk trees, also know as salt cedar, provide shade for rafters in the Grand Canyon, but they also overtake native vegetation. In Yellowstone, non-native lake trout that somehow were dumped into Yellowstone Lake decades ago today threaten to essentially wipe out the lake's native cutthroat fishery.
    In the Great Lakes, home to parks such as Isle Royale, Apostle Islands National Lakeshore, Sleeping Bear Dunes National Lakeshore, and Indiana Dunes National Lakeshore, among others, invasive species number nearly 200. One, the zebra mussel, has clogged municipal water intake systems and is blamed for playing a role in creating a "dead zone" in Lake Erie. Another, the round goby, has beaten down small-mouth bass populations.
    This week, in a bid to get Congress to pay attention to the problems, a coalition of groups aligned to restore the health of the Great Lakes called for a moratorium on ocean-going ships in the lakes.

    "Our call for a moratorium stems from the fact that the Great Lakes are under attack and Congress has yet to respond,” says Jeff Skelding, campaign director for the Healing Our Waters-Great Lakes Coalition.  “We have solutions. It is time to use them. Congressional delay is exacerbating the problem and costing citizens more money.
    "It is time for elected officials to pass legislation that will slam the door shut on new invasive species in the Great Lakes."
    According to the coalition, a new non-native species is found in the Great Lakes every 28 weeks. More so, (M)ore than 60 percent of all non-native invaders—54 of 85 invaders—discovered in the Great Lakes since the opening of the St. Lawrence Seaway in 1959 are attributable to ballast water discharge from ocean-going vessels.
       While the state of Michigan has tried to address the problem by enacting legislation to stop the spread of invasive species, the shipping industry has challenged the law in court.
    "Congressional inaction has caused the situation to degrade into a regional crisis marked by a lot of frustration and finger pointing, and very little in terms of results,” says Skelding. “Congress can pass comprehensive legislation now to combat invasive species. Until protections are in place, we stand committed to protecting the Great Lakes and its citizens through a moratorium on ocean vessel operation on the lakes and the use of transportation alternatives."
    Specifically, the coalition is pushing the Great Lakes Collaboration Implementation Act, legislation designed to prevent invasive species introductions, stop sewage contamination, and restore wetlands.
    "Every year Congress fails to act means another invasion that will destroy the lakes, undermine our economy and way of life, and then spread inland across North America’s freshwater resources,” says Jennifer Nalbone, campaign manager for Great Lakes United, the Healing Our Waters Coalition member which originally called for a moratorium on ocean-vessel access into the region.
    “It is time to take a stand for the Great Lakes and the nation’s freshwaters, and use available transportation alternatives until Congress provides a national solution to what is clearly a national problem."
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