It’s hard to keep up with the world of invasive species, but I thought I’d start off 2012 with some stories I’ve been reading and listening about lately. Let’s start with goats. A blurb in the current National Geographic (which my son reads religiously), sent me on a search mission, and I found out that goats are being used as weed eaters all over the place. Ewe4ic Ecological Services, a company that rents out goats in Colorado and Wyoming, has been hired to take care of all the following weeds (in alphabetical order, no less): Canada thistle, cheat grass, common tansy, common mullein, dalmatian toad flax, dandelions, downy brome, Indian tobacco, knapweed, kudzu, larkspur, leafy spurge, loco weed, musk thistle, oxide daisy, plumeless thistle, poison hemlock, purple loosestrife, scotch thistle, spotted knapweed, sweet clover, yellow star thistle and yucca. Goats also eat blackberry leaves, ivy (including the poisonous kind), Scotch broom, knotweed, morning glory, holly, nettle, and horsetail. My friend Christopher says that his goat will chow down on blackberry leaves from branches he prepares for her (to avoid the goat eating rhododendron, which is poisonous!). And a real bonus for this time of year â€“ goats love Christmas trees! They’ll strip them bare and tear off the bark for dessert. The closest cud-chewing invasive weed solution is Vegetative Management Services, Inc. run by Lewis Cochran, in Vernonia. Give him a call at 503-730-7065 for help with your weed problem.
On to beavers. In last month’s NatGeo (the magazine version), I found a blurb illustrating a classic invasive species story. Turns out that in 1946, Argentina imported about 50 (funny how different sources give different numbers here) beavers from Canada to Tierra del Fuego, an archipelago on the southern tip of South America, to start, of all things, a fur trade. The business never flourished, but the forgotten beavers did. They now number over 100,000, and have been busy (pun intended) altering the landscape. With no natural predators to check their advance, they’ve crossed the border into Chile (Tierra del Fuego is divided between Argentina and Chile), swum to the mainland, and laid waste to patches of forest.Â Christopher Anderson of the Institute of Ecology and Biodiversity in Santiago, Chile says, â€œThe change in the forested portion of this biome is the largest landscape-level alteration in the Holocene â€” that is, approximately 10,000 years.â€ (I love quotes like this that ignore human-caused changes.) Local authorities are looking into eradication (beavers) and restoration (forest). The eradication would be over the largest area ever, “by an order of magnitude,” according to Josh Donlan, director of Advanced Conservation Strategies, an Idaho firm working on the program. So, get ready for a sharp drop in the price of beaver pelts! Maybe that fur trade will pay after all! Check out Nature 453, 968 (2008), and a BBC News article called Argentina’s great beaver plague for more great quotes and factoids.
And now, to finish up, how ’bout a nice entrÃ©e of silverfin? (I first heard about this one listening to a podcast of Living on Earth entitled Let Them Eat Carp!) Yes, the venerable Asian carp, scourge of the Great Lakes, has been officially renamed and branded as silverfin, and is being marketed as the latest chic seafood dish. Like the Patagonian toothfish, which was obscure until the Chileans marketed it as Chilean sea bass (it’s now so popular that Greenpeace says it may be commercially extinct in less than 5 years), there has been a movement to solve the Asian (or silver or flying) carp problem by eating the highly invasive species. Silver carp were imported to North America in the 1970s to control algae growth in aquaculture and municipal wastewater treatment facilities. They escaped from captivity soon after their importation, and now are rampant in the Mississippi River watershed, threatening to enter the Great Lakes, home to a multi-million dollar fishing industry. Chef Philippe Parola, founder of Silverfin Craze, describes the taste of Asian carp (whoops, silverfin) as “a cross betweenÂ crabmeat and scallops!” Bon appÃ©tit!