Eating Invasive Species is More Adaptation Than Solution
From garlic mustard to lionfish, a nuanced examination of invasivorism.
There’s garlic mustard (Alliaria petiolata) all around my house in the Lower Hudson Valley. It is one of the first plants to appear in the Spring, well before ramps or even skunk cabbage. It spreads wildly and rapidly until the fall and some of it even stays around through the winter, peeking out from beneath the snow. I have become accustomed to eating it. As its name would suggest, it has a garlicky flavor. And it’s free. The same can be said for the Japanese knotweed (Reynoutria japonica) that shoots up like bamboo every spring. I’ll pickle some of the shoots, but there is only so much knotweed anyone could possibly eat. Both are highly invasive species and I like to think that I’m eradicating them by eating them, but it doesn’t matter how much I pull out of the ground, the garlic mustard and Japanese knotweed around my house will likely never go away.
Stories about eating invasive species have been widespread in modern media for the past few decades since conservation biologist Joe Roman developed the concept of invasivorism, as well as a great website dedicated to the act called Eat The Invaders. The general premise is a nice one: that by eating invasive species we can stop them from taking over the ecosystems they have entered into.
To successfully reduce the spread of an invasive species there needs to be the removal of enough of the organisms at proper stages in life to cause a decline in population growth and size. Depending on the size of the spread and the conditions of that ecosystem, that may require a massive undertaking. Is it possible?
Humanity is notoriously great at destroying populations of species, plus many of these ones even taste great. Additionally, chefs look like heroes by cooking them, and it brings in customers that feel like they are part of the solution. It seems like a win-win solution. Is it as straightforward as that?
Can we eat enough of them to make it matter?
In this hemisphere, the consumption of the invasive lionfish (Pterois volitans) is the story that’s told over and over again in food media. “Its hunger is legend,” Ligaya Mishan, wrote in The New York Times Magazine. “The predator has been known to graze on more than 50 species, and its stomach can inflate to 30 times its natural size to accommodate its feasts, which sometimes equal 90 percent of its body weight.”
These fish first appeared off the coast of Florida in 1985 and within a few decades spread to every part of the Gulf of Mexico. In a matter of weeks, they can deplete a coral reef of 80 percent of its native species and a single lionfish can spawn two million eggs per year, so their existence can be devastating there.
It is also true, however, that they are delicious. They have a sweet, white flesh that can be used for ceviches or they can be skewered or grilled. Governments from Colombia to the Bahamas have encouraged their consumption, as they should. There are lionfish derbies, where tens of thousands of these fish are hunted by spearfishermen over single weekends, and television chefs with massive public reaches prepare recipes with them or serve them at their restaurants to help spread the word.
The proliferation of lionfish in the Caribbean is a serious issue and food has been an easy way to create awareness about it. It’s beneficial for these ecosystems if the numbers are reduced in any form and we should be incorporating them into our local diets.
While lionfish is the perfect combination of nice tasting, beautiful to look at and not overly difficult to catch or process, it’s debatable if the consumption of lionfish in the Caribbean has been successful at limiting their spread or not. Numbers have dropped enough that native species have returned in many places, though efforts are still too concentrated on specific locations that a core population will likely remain. Lionfish will probably not be eradicated in the region even with additional support, but the populations might stay manageable if the momentum is maintained and can spread.
A similar incident is occurring in the Bolivian Amazon. Paiche or pirarucu (Arapaima gigas), a beloved and sometimes endangered freshwater fish in the Amazonian waters of Peru and Brazil, started appearing the Bolivia sometime in the 1970s after escaping from fish farms there, which have been instrumental in preserving the fish in their native range. Like lionfish, it’s a predatory fish, and it has depleted populations of fish like surubí and bagre in Bolivia. Still, Bolivia lacks an ocean, so new economies in remote river communities have been developed in catching and selling paiche. There is not enough information, however, to determine whether this has been enough to decline the spread of the fish.
What about less palatable invasive species?
It’s one thing to get eaters to line up for lionfish or paiche, but what about invasives that are far less appealing to local markets? Asian carp (Cyprinus carpio) that escaped from ponds in the southern U.S. have spread to the region’s rivers and are threatening to reach the Great Lakes, which could be just as destructive as the zebra mussels that have already invaded there (and no one wants to eat).
There was an actual effort to rebrand Asian Carp to Kentucky Tuna, which turned out to be illegal. Some have tried to create a local market for the fish, which can be delicious and has low levels of toxins, but Asian carp have a series of Y-shaped bones running through them that make them difficult to fillet or process. While some of the fish have appeared at splashy dinners, the profit margins have been too small to create a market within the U.S. Some areas have shown reductions of Asian carp populations by giving incentives to fishermen, though most of the catch gets thrown away. With hundreds of millions of dollars spent each year to eradicate the fish, very little of it is kept in food safe conditions and most of what is gets sent to Asia.
Then there is nutria (Myocastor coypus), the semi-aquatic rodent from South America that was introduced to various parts of the world in the late 1800s for their fur, as well as to rid the Mississippi Delta of water hyacinth. The fur trade collapsed long ago, but the rodent hung around and has spread wildly across North America, Europe and Asia, wreaking havoc on wetland ecosystems. While rodent meat (see my recent story on guinea pigs) has potential as a sustainable protein, few actually will eat it or put it on menus. Outside of some markets in Kyrgyzstan and rural hunters in Louisiana, where celebrated chef Paul Prudhomme once held an annual festival dedicated to eating it, it hasn’t caught on.
There have been minor efforts in eating the Burmese Pythons that are destroying the Florida Everglades and periwinkles that have taken root in the salt marshes of New England, but unless major infrastructure investments and public campaigns are enacted, eating invasives like these will have little impact.
Can creating markets for invasive species backfire?
If a market for invasives becomes valuable, what is the incentive to stop it? If populations of lionfish start declining enough that they are too difficult to hunt, will those making a profit from them just transition to something else? Or will there be economic reasons to keep them around?
There are fears that creating regional markets for invasive species could increase the demand for them and encourage their propagation:
“In Hawaii, pigs (Sus scrofa) were first introduced by Polynesian settlers and contemporary feral populations are protected and managed by the state's wildlife agency, which has no clear intention of ever eradicating the species from all the islands owing to their hunting value,” writes Martin A. Nuñez, in a study in the journal Conservation Letters. “The hunting benefit can be contrary to the main goal of the management programs (controlling invasive species), but pigs clearly confer an economic benefit. Many invasive species throughout the world positively affect the local economy, at least temporally, and this may be an important aspect to consider.”
Aside of isolated cases like this one, this doesn’t seem to be a major concern. Numbers of invasives like nutria or Asian carp are so big that few really believe it to possible, which is something to consider. This means few actually believe this to be a legitimate solution and aren’t willing to allocate the resources to make it realistic.
What about invasive species caused by global warming?
As much as we like to think they are, ecosystems are rarely stagnant. Changing climates are already having major impacts on what species can live where, and I keep coming across this issue wherever I travel.
In Vestmannaeyjar, an archipelago off of southern Iceland where I spent a summer co-authoring a book, there is no record of eating mackerel (Scomber scombrus). Within the past decade or so, because of warming seas, it has moved into Icelandic waters in a big way from the south and has quickly become one of the most important fish economically in the country, after cod. I’ll never forget going into a fish processing center on Heimaey and seeing ton after ton of mackerel being unloaded shooting out of a tube at rapid speed like some kind of strange fish cannon.
Yet, there are no recipes for mackerel throughout the history of Iceland. It didn’t exist there at all, so no one knows what to do with it. There have been some efforts to get Icelanders to eat it, but the amount is so vast that the country’s tiny population couldn’t make a dent on it even if they tried. The country has adapted their export model to include mackerel, but there’s no talk of ridding it from Icelandic seas as it’s not something they could control even if they wanted to.
Similarly, in Venice, Italy last year, I saw Atlantic Blue Crabs, (Callinectes sapidus) that were first reported in the Mediterranean in Venice in the 1990s. They have been spreading rapidly and feeding on the native species and quickly lessening the lagoon’s biodiversity. Fishermen used to toss them back in the water after finding them in their nets, though now restaurants around Venice, like Chiara Pavan and Francesco Brutto’s Venissa, are finding ways to incorporate them in local gastronomy, as they are with bluefish and jellyfish. Few expect them to be eradicated in this way, though if enough of a local appetite can be developed, they can allow native species to coexist there.
Is there a solution?
What if we catch an invasive species early enough and consume it then? There’s ample data that stopping a population before it really expands can be effective.
“There is evidence that harvesting programs could be effective if started when the target population is still small and concentrated,” Michael Snyder wrote in the magazine Scientific American.
He quotes a paper from the U.S. Fish and Wildlife Service that states that for there to be an impact the number of individuals harvested needs to exceed the number that would normally not survive during a single breeding cycle.
The problem is no one wants to devote the necessary resources to eating invasives before a major problem arises. The development of a model for a campaign that could be launched early and be expected to be only temporary is what is badly needed, though thus far the political and cultural will hasn’t happened anywhere. Adaptation is a last resort, but in most cases, this is what we are left with.
Even if we can stop a single invasive species at one time, their rise is a symptom of a much larger problem: our planet is out of whack. Unless we do something to maintain some balance in our ecosystems, to make these problems more manageable than they currently are, little of this will ever matter.