How non-native species can change the structure of an entire landscape
First arriving in the U.S. in 1876 at the Centennial Exposition in Philadelphia as part of an exhibit garden, kudzu was encouraged as an ornamental, groundcover and forage crop. Farmers in the U.S. were once encouraged to plant kudzu to help mitigate erosion, but the plant soon became a problem.
This semi-woody perennial is a climber, covering other plants and blocking out their access to sunlight. It will even grow on pavement and buildings, spreading as much as 1 foot per day. It can be found all over the south, in Midwestern and east coast states as well as Washington and Oregon.
According to the Center for Aquatic and Invasive Plants at University of Florida, about 2 million acres of forest in southern states has been taken over by kudzu. To prevent it from growing back, the plant must be completely destroyed and replanting over it is the best way to make sure it won’t come back.
Barbara Tomey says that her garden in Georgia was completely destroyed by the invasive species. To get it out, she had to cut it back every two or three weeks for more than two years to get rid of it.
“It’s indestructible,” she says. “You just can’t get rid of it no matter how hard you try.”
Goats have become a popular solution to the problem since kudzu is high in protein and makes a great animal feed. Basket makers have found that the vines are great material for their creations. Best of all, you can eat it, make wine from the petals and even replace spinach with it.
Beautiful but dangerous, the lionfish has made its way from its native tropical waters in the Indian and South Pacific oceans to the Atlantic, where it’s devastating coral reefs. Introduced in the 1980s, the fish became a problem in the U.S. in 2000. A year later, they were seen in Bermuda and they were spotted in the Bahamas in 2004.
While they might be a beautiful addition to an exotic aquarium, lionfish are ravenous eaters with the ability to reproduce every four days. With venomous spines, they have great protection and without any native predators, they eat up local fish and crustaceans in astounding numbers. In fact, their diet includes nearly 50 different kinds of fish and crustaceans and their stomachs can expand to 30 times their original size after a meal.
Now in the Gulf of Mexico, the Caribbean islands, northern South America, Central America, Bermuda and the Atlantic, the lionfish is having a serious impact on fragile coral reefs. The reefs rely on herbivorous fish that eat algae and seaweed that can overgrow the coral. Environmentalists are also concerned about the potential impact on commercial fishing and tourism as they spread.
Some say the problem started when six lionfish escaped from an aquarium during hurricane Andrew in 1992, but others say that it’s the result of aquarium collectors releasing fish into nonnative waters.
The Reef Environmental Education Foundation recommends eating the fish as one option to help cull their numbers. They’ll even show you how to fillet the fish to avoid its poisonous spines and show you how to cook it.
The Indian myna or common mynah is one of the International Union for Conservation of Nature’s 100 World’s Worst Invaders, and for good reason. Native to southeastern Asia, they’re known as the Farmer’s Friend in India where they eat up crop pests. For just that reason, they’ve been introduced to Australia, Canada, New Zealand, South Africa and other countries.
However, in Australia in particular, they’ve been known to cause crop loss and disease and threaten native bird species. They’ve become such a problem that popular vote awarded them the Pest of Australia Award from the Australian Broadcasting Company in 2005. Mynas will not only attack other birds, but they’ll steal nests and stop native birds from breeding. They’ll even destroy eggs and kill chicks and displace small mammals to make their nests in hollows.
In agricultural areas, mynas have become an economic problem, damaging crops and spreading disease. These omnivores will eat anything from bugs to grains to vegetables to fruit and have been known to cause serious damage to crops from strawberries to bananas to wheat to figs. Their varied diet also includes seeds and contributes to the spread of weeds.
The bird has adapted well to urban environments where they’re a threat to human health. The birds have been known to attack people and they can spread diseases like avian flu, mites that can cause dermatitis in humans and salmonellosis. Just over 100 birds were released in Canberra, Australia’s capital, between 1968 and 1971. By 1994, the average population was 75 birds per square kilometer.
Humane killing of these birds is allowed in Australia through trapping and poisoning. There are also programs to encourage planting of native species to help native species regain territory.