Invasive species are on the move

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Mountain ranges, oceans, deserts, rivers, and other landforms divide the world into different regions and zones. These natural barriers isolate plants and animals from each other, and allowed many different species to evolve. Over millions of years, nature found different solutions to the unique situations within each enclave, and we ended up with wildly different ecosystems – each with some plants and animals that can’t be found anywhere else.

Unfortunately, the walls between these ecosystems are crumbling. The world is growing increasingly flat, with trade and travel between regions occurring every day. Cargo ships from China regularly travel to Seattle and Melbourne, and their bilge tanks can give fish and clams a free ride. Business travelers who step in mud in one airport unknowingly carry bacteria across mountains in a single flight. Tourists often bring exotic flowers home.

As a result of global trade and travel, many of the plants, animals, and bacteria that were isolated to small areas are now spreading out over the entire world. Some of these organisms are thriving in their new homes, and endangering native plants that were already there in the process. Many elm trees in New York had ancestors in the Netherlands or France, and are dying off due to Dutch Elm Disease. Bees raised in Poland have to worry about parasites that originated in Southeast Asia.

Invasive species are shaping the news. For example, wood boring insects are threatening the few remaining old growth forests in America, which has led to a shortage of firewood. Strangely, the shortage isn’t due to a shortage of trees. Instead, because these insects love to travel inside dead trees, restrictions were put in place to control the transport of lumber. If you live in an affected area, you may want to check out cured firewood as an alternative. Cured wood is wood that’s been heated in a kiln to dry it out. It’s not only unaffected by the restrictions, but it also has a much higher heating value per pound.

The Great Lakes are also threatened by invasive species. Zebra muscles and snakefish do not have any natural predators, so they’re displacing many native species in the area. Game fish are threatened, along with industries that use fresh water from the lakes (zebra muscles tend to clog intake pipes). To combat the problem and prevent the introduction of new species, the Federal government has passed restrictions on how ballast tanks are treated.

Invasive species are also a threat outside the United States. In Mexico City, the iconic Aztec ‘Water Monster’ is facing new threats from exotic fish. This salamander has a long history in the region, but is unable to cope with habitat loss, pollution, and competition from tilapia. Plans are underway to build sanctuaries for the Water Monster as well as native aquatic plants.

If that doesn’t work, there may be an option B. Researchers at RIKEN research institute in Yokohama, Japan have been successful in cloning mice that were frozen for 16 years. The researchers are still a ways away from using the technique on Woolly Mammoths, but conservationists may someday be able to use frozen tissue samples from other endangered species to bring them back or to supplement genetic diversity within wildlife preserves. Even if invasive species move in and gobble up all the native plants and animals, there’s a hope of reintroducing native species back to their homes.

Photo courtesy of serdir (at home) at