April 16, 2012
Filed under Feature Stories
What’s the greatest threat to natural ecosystems in North America? Forget global warming. Quit pondering pollution. A growing number of scientists are convinced the evidence shows that invasive species pose a stronger risk to many ecosystems.
According to the National Invasive Species Information Center (NISIC), two characteristics make an organism invasive. First, it is alien to the ecosystem under consideration. Second, its introduction causes or is likely to cause environmental or economic harm. Some non-native species such ring-necked pheasants were deliberately introduced to America, yet do not cause negative impacts to the environment. On the other hand are species such as house sparrows and European starlings, both of which displace native birds from nesting sites and may become agricultural pests. Starlings and house sparrows meet the technical classification of invasive species while ring-necked pheasants do not.
Invasive species include all types of organisms: animals, birds, plants, aquatic creatures, insects and microbes. In some cases, non-native species may threaten the very existence of the local organisms. Zebra mussels, an exotic shellfish from the Black and Caspian seas, found their way to North America’s Great Lakes in the bilge water of ships. These tiny mussels soon starved out native mussels in many areas, also disrupting the food chain that nourished larger creatures such as salmon and trout. Where they’ve become established, the presence of zebra mussels has eliminated or compromised the very existence of many native, water-dwelling creatures.
Like it or not, invasive species are here to stay. But motivated people can significantly reduce their impacts on native environments. Here are some ways you can combat various categories of invasive species.
When camping, hiking or traveling, be aware of your potential to transplant. Seeds from harmful plants can lodge in the cuffs of pants or in the creases of hiking boots. They’ll stick to mud on your car or get caught in the bumper. Educate yourself on invasive plants where you recreate and don’t be a seed spreader. Also avoid transporting firewood from one location to another as exotic insects and diseases can be carried in wood as well.
Individuals transporting watercraft such as boats, canoes and kayaks must be especially vigilant as these organisms often hitchhike from one body of water to another. Follow state agency recommendations for cleaning your craft, or rent a boat from a local source.
Anglers can also accidentally transport aquatic invasives on their waders and fishing gear. Educate yourself on methods for keeping your fishing gear clear of non-natives. Conservation groups such as Trout Unlimited are excellent resources.
Wildlife agencies also need our help managing the spread of non-native species. Nationwide, the cost of effective control efforts requires billions of dollars. Your contribution to local efforts is important. For example, a lake I frequent in New York’s Adirondack Park has become infested by Eurasian milfoil. A local conservation group is working diligently to stop its spread with much of the group’s efforts funded by donations. Each year I make a contribution.
No matter how you participate, our native species of plants and wildlife are dependent upon our vigilant efforts to combat alien invaders.