by Scott Moeller
When it comes to water quality, the state of Minnesota takes non-native (exotic) species very seriously. There are stringent rules in place to prevent or control the spread of invasive exotics like Eurasian water milfoil, zebra mussels and invasive carp. Even potentially beneficial exotic species, like ones used for biological controls are rigorously tested, to be sure they aren't a threat, before being released into the native environment.
But much of our current knowledge about the potential dangers of invasive species has come as a result of the past mistakes of others. As foolish as these mistakes may seem to us now, they provide valuable lessons that serve as the foundation for how we protect our environment from invasive exotics today.
Here now is a brief summary of some historically terrible moments in the annals of invasive species history.
Date: October 1859
Location: Winchelsea Victoria, Australia
Description: Citing a lack of rabbits to shoot at, wealthy British landowner Thomas Austin asks his nephew to send him 12 gray rabbits from England, and subsequently releases the rabbits on his property. Within ten years, these 12 rabbits established a population numbering in the tens of millions that still plagues the continent to this day.
Date: June 1935
Location: Queensland, Australia
Description: Their senses clouded from stepping over heaps of rabbit carcasses for 75 years, the Australian sugarcane industry releases Hawaiian Cane Toads to help control native cane beetles. Ignoring the warnings of scientists and naturalists, 102 toads are released. The toads are unsuccessful at controlling the beetles, but are successful in proliferating to a population of 100's of millions.
Date: Spring 1850
Location: Brooklyn, New York
Description: Desiring to establish wildlife familiar to European immigrants, Nicholas Pike, Director of the Brooklyn Institute, purchases 8 pairs of house sparrows from England for $200. He releases them into the city, but none survive. Never one to give up on a bad idea, Pike “kicks it up a notch,” buys another 25 sparrows, and releases them the following year, thus establishing the origins of one of the most abundant invasive bird species in the United States.
Location: Central Park, New York
Description: Not willing to be outdone in shortsighted foolishness by his contemporaries, Eugene Schieffelin releases 60 European starlings into the wilds of Central Park. A member of the American Acclimatization Society, Schieffelin and his colleagues specialize in the absolute inability to learn anything from the previous bad ideas of others, and strive to allow New Yorkers to “see all the birds mentioned in the plays of William Shakespeare.” With such a worthy goal, we can surely excuse him for singlehandedly establishing the 200 million-strong population of one of the most destructive invasive bird species in North America.
Description: The California Experiment Station imports Smooth Brome grass seed from Asia and distributes it across the United States to be used as forage and erosion control on farms and newly-constructed road ditches. The plants spread rapidly through aggressive underground rhizomes and seeds, signaling the beginning of the end for native tallgrass prairies throughout the Midwest.
Location: Great Lakes
Description: A European cargo ship captain discharges contaminated ballast water into the waters of the Great Lakes, releasing non-native zebra mussels. Initially discovered in 1988, the rapidly reproducing mussels easily attach themselves to rocks and vessels, and have since spread throughout all of the Great Lakes, the Mississippi River and its tributaries.
Location: Sonoma California, USA
Description: J.A. Poppe imports just five specimens of common carp from Germany and allows them to reproduce in private ponds to sell for food. Five years later, the U.S. Fish Commission follows Poppe's lead and begins importing and distributing live carp throughout much of the U.S. Many of these fish were stocked in farm ponds, but escaped to open waters with flood events. They are now found in nearly every state, and regarded as pests due to their impact on aquatic vegetation and water clarity.
Description: The Centennial Exposition in Philadelphia includes a large garden filled with plants from Japan which include a flowering vine known as kudzu. Many years later, southern nurseries sell the live plant and, with the advent of the Great Depression of the 1930s, the US government's own Soil Conservation Service promotes the planting of thousands of acres of kudzu for erosion control. The fast-growing vine now covers (literally) over 10 million acres throughout the southeast United States.
So, what's the take-home message in all of this? First, it's easy to poke fun and lay blame on past individuals and agencies who made these seemingly short-sighted decisions. It is largely from these huge mistakes, however, that we have learned how dangerous invasive species can be. Let's not continue to repeat the mistakes of the past, especially when it comes to our precious water resources here in Minnesota. Go to the MN DNR invasive species pages to educate yourself, and stay on top of invasive species issues.
Oh, and don't ever pay more than $100 for a house sparrow.