May 15, 2012
Eating Invasive Species to Stop Them?
Japanese knotweed—a common spring edible and a relative of rhubarb, quinoa and spinach—grows like crazy, so much so that it’s considered an invasive species. Brought here as an ornamental, it’s now better known as a blight; Monsanto even makes a herbicide dedicated to its eradication. On my afternoon jogs, I’ve often wondered what might happen if all my neighbors descended on the rapidly proliferating patches and harvested the tender young shoots for tart, tangy additions to their dinner.
The idea that armies of hungry knife-wielding “invasivores” could eradicate exotic invasive flora and fauna has taken hold in popular culture and among conservation scientists. There are at least two invasive species cookbooks. Fishermen hold tournaments to chase down the Asian carp, which escaped Southern ponds and now threatens to invade the Great Lakes, and biologists have even attempted to re-brand the fish as delicious “Kentucky tuna.”
Eating invasive species might seem like a recipe for success: Humans can devastate a target population. Just take a look at the precipitous decline of the Atlantic cod (PDF). Perhaps Asian carp and lionfish, too, could be sent the way of the passenger pigeon. It’s a simple, compelling solution to a conservation problem. Simply put, “If you can’t beat ‘em, eat ‘em.”
However, as ecologist Martin A. Nuñez cautions in a forthcoming article in Conservation Letters, edible eradication strategies could backfire and might even lead to a greater proliferation of the target species. First off, harvesting plants or animals for food doesn’t always correspond with ecological suppression. (Harvesting knotweed, for example, doesn’t require uprooting the plant, which can easily reproduce even after being picked). While the eat-‘em-to-beat-‘em effort calls attention to unwanted species, in the long run, Nuñez says popularizing an introduced species as food runs the risk of turning invasives into marketable, regional specialties (as with Patagonia’s non-native deer, fish and wild boar).
Before dismissing his cautionary note about incorporating alien flora and fauna into local culture, it’s worth remembering one of America’s cultural icons, a charismatic animal that may help underscore the questionable logic behind the invasivore diet: the Equus caballus, a non-native species originally introduced by Spanish explorers to facilitate transport in the Americas. Now, Nuñez writes, these “wild” horses have become “so deeply rooted in American culture and lore that control of their populations is nearly impossible, and eradication unthinkable.” To say nothing of eating them.
Drawing of Japanese knotweed (Polygonum cuspidatum)/Curtis’s Botanical Magazine, Volume 106, 1880.
Thanks to Roberta Kwok at Conservation magazine, who brought my attention to the study.
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Since Equus ferus caballus is the name for domesticated Equus ferus ferus, and since Equus ferus ferus has been shown to be genetically identical and synonymous with North American Pleistocene taxa, the feral horse is a reintroduced species rather than an invasive one.
Reintroducing Przewalski’s, Onagers (conspecific to Yukon Wild Asses), Grévy’s zebra (Hagerman horse), and Kiangs (New World stilt-legged horse) wouldn’t hurt either.
North America hasn’t had an intact ecosystem for at least 9000 years.
It’s wonderful to see an intellegent answer about the wild horses of America stating the fact that they are reintroduced species rather than an invading one. Apparently the person who wrote this article is not aware that there were horses that had been here before the Spanish explorers appeared, but that the native peoples had hunted them for food to the point of extinction. They had not considered using the animals for transportation purposes until after the Spainiards appeared with their horses. In fact, in the beginning, the native people were afraid of these horses and believed that the horses would eat them.
Very nice comment, Fancylads.
The Younger Dryas wiped out a marvelously endowed North American Pleistocene ecology. This should be sobering to climate change deniers, but a lot of them believe the world was miraculously created 5000 years after the end of the Younger Dryas.
This is an interesting article. However, if a reader wanted to take the next step how would they find out which invasive plants are edible, and which are not? You only listed one plant with a 132 year old illustration. Many plants look alike. The article could have been improved by providing the additional information of which invasive plants are edible and which are not.
Garlic mustard is invasive in Michigan. In the spring, the residents harvest the tender leaves for salad and uproot the rest. Eat ‘em to beat ‘em has to include strategies for eradication as well.
For the curiously hungry:
http://invasivore.org
I’d like to thank Fancylads for bring up the point that the horse was effectively a reintroduced species. I’d also like to state that the horse itself is a poor choice in a warning about normalizing invasive species for food. The horse is an animal that has been deemed useful in society, due to its’ use as a pack animal, and has even been named at times being treated the same way as a pet. However, the only use society appropriates for the Asian carp is that it is food. Being an invasive species, it’s not useful for anything else but to be eaten. We do not name wild fish. Therefore, it is inappropriate to compare a useful animal which is not typically used for food, like the horse, with an animal that isn’t too useful outside of being food, such as the Asian carp. Lastly, I’d like to comment on Fellfeline’s comment. The claim that he made that the extinction of North America’s prehistoric horse caused temperatures to rise on Earth during the Pleistocene era just makes him sound like an idiot. This opinion is only reinforced when he goes into his tirade regardig whether the Earth was created 5,000 years ago or not.