Invasive Species: To eat or not to eat, that is the question

Abstract

Managing invasive species is a current challenge for biodiversity conservation. A recurring recent suggestion is that by harvesting nonnatives for human consumption, people can control invasive populations. Even though humans may be able to control or eradicate certain populations of nonnative species by harvesting them as food sources, several caveats should be considered before starting these programs. A prominent problem is that creating a market engenders pressure to maintain that problematic species. Also, if the target species becomes an economic resource, people may try to recreate that market in previously uninvaded regions. Using invasive species as an economic resource may trigger the local community to protect these harmful species, to facilitate their incorporation into the local culture, and can generate severe management problems. As with other management programs, managers must know if the harvest actually reduces the target population. Mortality could produce a reduction in the population size or growth, or it could be compensatory, in which case removal of the harvested individuals would not affect population growth. However, in addition to possible control, there may be several benefits of this approach, including an opportunity for public outreach. Projects aiming at controlling invasives through human consumption should be carefully examined, as they may produce results opposite to those proposed.

Full text

POLICY PERSPECTIVE
Invasive Species: to eat or not to eat, that is the question
Martin A. Nu ˜
nez, Sara Kuebbing, Romina D. Dimarco, & Daniel Simberloff
Department of Ecology and Evolutionary Biology, The University of Tennessee, 569 Dabney Hall, Knoxville, TN 37996, USA
Keywords
Biological invasions; culinary culture;
gastronomy; lionfish; management.
Correspondence
Martin A. Nu ˜
nez, Department of Ecology and
Evolutionary Biology, University of Tennessee,
569 Dabney Hall, Knoxville, TN 37996, USA. Tel:
(865) 974-8648; fax: (865) 974-3067. E-mail:
nunezm@gmail.com
Received
8 December 2011
Accepted
5 April 2012
Editor
Phillip Levin
doi: 10.1111/j.1755-263X.2012.00250.x
Abstract
Managing invasive species is a current challenge for biodiversity conservation.
A recurring recent suggestion is that by harvesting nonnatives for human con-
sumption, people can control invasive populations. Even though humans may
be able to control or eradicate certain populations of nonnative species by har-
vesting them as food sources, several caveats should be considered before start-
ing these programs. A prominent problem is that creating a market engenders
pressure to maintain that problematic species. Also, if the target species be-
comes an economic resource, people may try to recreate that market in pre-
viously uninvaded regions. Using invasive species as an economic resource
may trigger the local community to protect these harmful species, to facilitate
their incorporation into the local culture, and can generate severe manage-
ment problems. As with other management programs, managers must know
if the harvest actually reduces the target population. Mortality could produce
a reduction in the population size or growth, or it could be compensatory, in
which case removal of the harvested individuals would not affect population
growth. However, in addition to possible control, there may be several benefits
of this approach, including an opportunity for public outreach. Projects aim-
ing at controlling invasives through human consumption should be carefully
examined, as they may produce results opposite to those proposed.
Introduction
Different approaches are widely used to control inva-
sive introduced species, including chemical application,
mechanical or physical removal, and biological control
(Simberloff 2001). An approach based on removal of indi-
viduals, harvesting and eating nonnatives, is occasionally
proposed and is recently gaining in popularity (Franke
2007; Rosenthal 2011). The idea that human consump-
tion can control nonnative populations accords with one
of the most important hypotheses to explain invasion
success, the enemy release hypothesis, which proposes
that invasives thrive because of the lack or scarcity of
enemies in the new range (Keane & Crawley 2002).
The idea of eating invasive species is not new. For
example, eating invasive species (e.g., weeds) has been
proposed previously for other reasons, including as a
good food source given their ubiquity and abundance
(Rapoport et al. 1995; Diaz-Betancourt et al. 1999). Many
cookbooks focus solely on recipes for invasive species, like
kudzu (Baldwin 1999; Reed 2002). Human consumption
as a way to control invasive species is not a new idea
either, and it has been applied several times in previ-
ous decades, for example, to target nutria (Myocastor coy-
pus) in Louisiana, USA in the 1990s (Boudreaux Bodin
1998). However, the idea that by eating invasives, hu-
mans can significantly affect their populations has re-
cently surged in popularity among government agen-
cies, conservation groups, and the media (e.g., Barclay
2011; Minsky 2011; Rosenthal 2011; Vozella 2011). A
few current examples include the Illinois Department
of Natural Resources “Target Hunger Now!” campaign
that seeks to feed the hungry and decrease nonnative
Asian carp (Hypophthalmichthys nobilis) in state waterways
(McCloud & Solano 2011), the U.S. National Oceanic
and Atmospheric Administration’s “Eat Lionfish” cam-
paign that promotes consumption of the marine in-
vader the lionfish (Pterois volitans) (NOAA 2011),
and the Mid-Atlantic Exotic Pest and Plant Council’s
“Eat Those Invasives!!” initiative that suggests harvest
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nez et al.Eating invasive species
strategies and recipes for common invasive plants of the
region (MAEPPC 2011). Many other invader recipes, all
of which are proposed to help reduce their impacts, are
currently advertised online and in print, for example, on
the website invasivore.org or in the “Conservation through
Gastronomy” cookbook (Franke 2007).
The notion that we can control species by eating them
is based on the assumption that, as well-known voracious
predators and owing to our huge and growing population
size, we can control species’ populations or even drive
them to extinction (which can be analogous to a suc-
cessful eradication program). The primary evidence in fa-
vor of gastronomic control is the many species humans
have driven to extinction or near-collapse by overhar-
vest. One such a collapse is the crash of the Atlantic cod
(Gadus morhua), which the fishing industry overharvested
decades ago; even under strict management the popu-
lation has yet to recover fully (Murawski 2010). Other
species at risk of extinction owing, in part, to current or
past overharvest are American ginseng (Panax quinque-
folius) (McGraw 2001), several palm species (for use of
palm hearts as a food) (Johnson 1996), and the spiny-
tailed iguana (Ctenosaura bakeri) of Honduras (Pasachnik
et al. 2009). Examples of extinct species lost in large part
from overharvest include moas in New Zealand (Hold-
away & Jacomb 2000), the woolly mammoth (Nogu´
es-
Bravo et al. 2008), and the passenger pigeon (Extopistes
migratorius) in North America (Halliday 1980).
Despite the fact that humans could potentially con-
trol or eradicate populations of nonnative species through
gastronomy, several caveats should be considered. These
programs could produce some unintended consequences,
and they may produce results opposite to those proposed.
These consequences could include the promotion of fur-
ther invasions and the obstruction of future management
plans (see below for a discussion of these points). It is im-
portant to remember that there are many differences be-
tween the species previously mentioned which, for sev-
eral different reasons, were susceptible to human harvest
pressure and the problematic species that are currently
invading. For example, there is strong evidence that non-
native invasive species have higher growth rates, fewer
pathogen and natural enemy attacks, and benefit more
from disturbance than most native species (e.g., Keane &
Crawley 2002; Klironomos 2002; Callaway et al. 2004; Hi-
erro et al. 2006; Ramula et al. 2008), making invasives
likely to be less susceptible to continuous harvest in com-
parison to their native counterparts. Here we analyze the
pros and cons of attempting to control invasive species by
eating them. We refrain from addressing particular har-
vest techniques, which are numerous and in some in-
stances need further development for successful harvest
programs (e.g., Thresher 1996; Yonekura et al. 2007), but
we focus on the general issues of this approach. We dis-
cuss if, when, and how the approach of controlling non-
native species via gastronomy should be used.
Benefits
A number of benefits are associated with attempting to
manage nonnative species by eating them. Further we
describe the three that are especially important.
Increasing awareness of invasive species
Programs aiming to control invasions will educate their
participants about the problems associated with invasive
species (e.g., invasivore.org). This is particularly clear be-
cause people willing to work for these programs might
be keen to understand more about invasive species and
to share their knowledge with other members of their
community. This type of outreach is analogous to other
citizen-science programs in which nonscientists aid sci-
entists in their research (Bonney et al. 2009) and also to
some control programs organized by many local conser-
vation organizations in which volunteers contribute to
the mechanical removal of invasive species (Simberloff
2003). In addition, invasive harvest programs have the
potential to attract interest from public sectors that are
not typically focused on resolving environmental issues.
Local chefs and food groups have been instrumental in
raising awareness of edible invaders, but only after they
learned about the use of invasive species through harvest
programs (e.g., Food & Water Watch 2011; Vozella 2011;
Walton 2011). Some individuals who initially participate
in a harvest program for the food value may learn more
about the impacts of nonnatives and eventually partici-
pate in “traditional” management programs not aimed at
eating nonnatives. Outreach seems a clear, positive aspect
of harvest programs.
Assisting in early detection and rapid response
efforts
Early detection and rapid response (EDRR) initiatives
have been proposed as a key technique for successful
eradication of new invader populations. However, for
EDRR to function, people must be able to identify species
of concern correctly and there should be many observers
frequently visiting a wide range of habitats. Programs ed-
ucating people on using invasives as food could promote
identification of invasive species to the nonscientific com-
munity and have the potential to facilitate EDRR, in anal-
ogous fashion to similar successes of citizen-science pro-
grams aimed at teaching about invasive species (Jordan
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Eating invasive species M. A. Nu ˜
nez et al.
et al. 2011). Many websites couple identification keys
with suggested recipes to insure accurate identification of
the invader (IPANE 2011; MAIPC 2011). If more people
are able to identify problematic invasives, it is more likely
that they will successfully detect a range expansion or the
arrival of invading species in a new region.
Boosting local economy
It is important to remember that some invasives are part
of the local economy and incorporating them into their
culinary culture may be an important source of local in-
come. For example in Patagonia, a local delicacy is food
based on hunting of nonnative red deer (Cervus elaphus),
hare (Lepus europaeus), and salmonid fishes (Salvelinus
sp., Salmo sp., and Oncorhynchus mykiss) (Lambertucci &
Speziale 2011). In Hawaii, pigs (Sus scrofa)werefirstin-
troduced 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 (Fujimori 2003). The hunting benefit can
be contrary to the main goal of the management pro-
grams (controlling invasive species), but pigs clearly con-
fer an economic benefit. Many invasive species through-
out the world positively affect the local economy, at
least temporally, and this may be an important aspect to
consider.
Problems, challenges, and possible unintended
consequences
Besides the benefits that programs based on control-
ling species via gastronomy can have, a number of se-
rious potential problems, challenges, and possible unin-
tended consequences are associated with this approach.
A few might even prove counterproductive for control-
ling nonnatives. Here we describe some of these potential
pitfalls.
Failing to affect invader population size,
expansion, or growth
To be successful, any management campaign using me-
chanical removal must insure the removal of enough
individuals of vulnerable life history stages to cause a
decline in population growth and size. Eating invader
campaigns are no exception. A central aspect of many
management plans should focus on insuring individu-
als removed are additive deaths (affecting population
growth) and not simply a form of compensatory mor-
tality (no effect on population growth; Crouse et al.
1987). Species-specific demographic matrix models and
elasticity analyses are ideal for targeting the correct life
stages and densities to cause population declines (Ramula
et al. 2008). Because lack of demographic information
on the target species is common in many management
plans, this could also be problematic for gastronomical
management.
Many campaigns to harvest plants do not kill the target
species, but instead solicit removal of leaves (e.g., kudzu),
fruit (e.g., eglantine, autumn olive, blackberry), or stems
(Japanese knotweed), leaving behind reproductive parts
that can later resprout or reseed. In a review of invasive
plant demographic models, Ramula et al. (2008) found
that on average a 60–95% reduction in growth or fe-
cundity was necessary to change population growth rate
from increasing to a decreasing for invasive plant species.
This implies that “light” gastronomical harvest, such as
removal of edible parts and not the entire individual, may
be ineffective unless it is coupled with other management
methods. Harvest of invasive animal populations might
have higher success rates, because harvest nearly always
removes entire individuals from the population. Yet, food
harvest of entire individuals does not always guarantee
success if the proper life stages are not harvested in large
enough numbers from the population, which can be no-
tably challenging (Thresher 1996; Kolar et al. 2010). It is
also important to consider the spatial extent of the non-
native population. If the plan is to harvest specimens to
supply local customers or restaurants, it may be imprac-
tical to collect in areas with low densities or in remote
areas. Therefore, it may not be a reasonable strategy to
control the species, if viable satellite populations in inac-
cessible areas remain unharvested.
The case of lionfish (P. volitans) exemplifies some of the
challenges of using human consumption to control an in-
vasive species. Lionfish have been released from aquaria
along the Florida coast, and in the last 20 years, they have
become a problematic species whose nonnative range has
now expanded drastically, extending from the Florida At-
lantic coast to the Gulf of Mexico and Caribbean Sea
(Schofield 2009). The lionfish has been proposed recently
as an ideal candidate to control by consumption. This
possibility has been widely publicized in U.S. media, in
part because of the tremendous potential detrimental ef-
fects of lionfish on local ecosystems and its culinary value
(NOAA 2011; Rosenthal 2011; Walton 2011). However,
research suggests that reducing invasive lionfish popula-
tions in large areas is not feasible in the long term because
of their fast recovery after severe overfishing and their
current widespread distribution (Barbour et al. 2011).
If the harvesting invader campaign is marketed as a
way to decrease the population size and ecological im-
pact of a species, a lack of success may create a backlash
toward the overall goal of managing the target nonnative.
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As with other failed attempts to control invasive species,
local people may get frustrated after years of effort and
may be convinced no methods exist to control the spread
of nonnatives, which can hinder future management
attempts.
Creating a market for a problematic species
that, with time, will need to be maintained
The ultimate goal in most eating invader campaigns is to
eat the target species out of existence, just as humans
have done for many native species. However, once a
species becomes a genuine economic resource, it could
be even harder to encourage complete removal of the
monetarily valuable species. What began as an attempt at
eradication or control could emerge as a marketplace that
demands a species be kept at levels at which harvest for
commercial purposes is viable. Invasive species with high
economic value tend to be protected (see below). Elimi-
nating jobs or reducing the income of local residents who
formerly earned a living by trapping, hunting, or raising
nonnatives for food may trigger negative responses by the
local citizens who value their current welfare more than
they deplore a negative ecological effect of the invasive
species.
There are many examples of how hard it can be to per-
suade the public to forgo purchasing or propagating in-
vasive species that are a valuable source of income. This
is the case even when species cause important deleteri-
ous problems to the environment. Some nonnative in-
vasive plant species are popular commodities in forestry,
horticulture, or traditional medicine industries. Forestry
in the southern hemisphere is based on nonnative trees,
for example, many pine species, and many of them are
highly invasive (Simberloff et al. 2010). However, ow-
ing to their huge importance for regional economies,
attempts to stop planting invasive trees are impractical
(Richardson 1998). In North America, a major introduc-
tion pathway for invasive woody plant species is the
horticulture industry (Reichard & Hamilton 2001), but
because woody plants yield over $3 billion in annual hor-
ticultural nursery stock sales in the United States (over
82% of sales in this market) (USDA 2010), it is not triv-
ial to convince the industry to cease selling profitable
species, even if they are highly invasive. Single nonnative
species can have great economic value and produce ma-
jor clashes between environmental groups and the hor-
ticulture industry. In Connecticut, USA, the ornamental
shrub Japanese barberry (Berberis japonica)islistedasan
invasive species by the state’s Invasive Plant Council but
it has proven difficult to prevent its sale because it has an
estimated annual crop value over $5 million (Lehrer et al.
2006). Although these examples are of invasive species
not promoted for human consumption, they neverthe-
less shed light on the challenges on controlling species
that generate economic benefits.
Some invasive animals are also integral components
of hunting and fishing industries and are regularly
used as food sources. Many nonnative game species,
such as brown trout (Salmo trutta) in New Zealand
(Veitch & Clout 2001) or red deer (C. elaphus) in Patag-
onia, are important to the hunting and fishing indus-
tries. These species are unlikely to be eradicated when
pressure to maintain populations is high (Lambertucci &
Speziale 2011).
Promoting further invasions
If a species becomes a genuine economic resource, this
may trigger its spread. People living in areas where the
species is not currently found may relocate invasive in-
dividuals in an attempt to imitate successful businesses
in the invaded area. Illegal fish stocking is an interna-
tional problem, with people introducing nonnative, in-
vasive fish to supplement native fisheries (Johnson et al.
2009). An example of this is northern pike (Esox lucius),
which is a common species in sport fishing. It was intro-
duced illegally in Lake Davis, California, USA for fishing
in the 1990s. Campaigns to control and eradicate the fish
have been in place since its discovery given the large im-
pact and devastating effect that this carnivorous fish has
in the lake and the threat it poses to the native fisheries in
California because Lake Davis empties into a larger water-
shed system (the Sacramento—San Joaquin delta system;
Aguilar et al. 2005). After a successful program to erad-
icate the invasive northern pike, locals are believed to
have reintroduced the species to promote fishing, which
was an important source of income for the local economy
(Elmendorf et al. 2005).
Harvesting may also promote further invasion by unin-
tentional dispersal of propagules. This might be especially
important when harvest is of viable parts of the speci-
mens like seeds, bulbs, or living individuals. By increas-
ing the number of people harvesting a species, we also
increase movement of it, which may be problematic.
Promoting incorporation of invasives into local
cultures
If the species becomes a desirable target, local people
can make it impossible to eradicate or control because of
cultural attachments to the species (Nu ˜
nez & Simberloff
2005). Examples abound of invasive species used as food
source that are ingrained in local culture. In the Hawaiian
Islands, controversy exists between conservationists and
hunters over the control of wild boar, introduced
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Eating invasive species M. A. Nu ˜
nez et al.
originally as a food source (Burdick 2006). Wild boar is a
species with well-known drastic effects, given their abil-
ity to modify entire ecosystems (Nogueira et al. 2009).
The native people of Hawaii have historical, strong ties
with the species as a food source. Also, traditions and
rituals associated with hunting wild specimens promote
the boars’ presence in Hawaiian forests and leave no cul-
turally acceptable alternatives to boar hunting (e.g., pur-
chase of pigs in grocery stores; Burdick 2006). Nonna-
tive red deer (C. elaphus), salmonid fishes (Salvelinus sp.,
Salmo sp., and O. mykiss) and wild boar (S. scrofa) in Patag-
onia are problematic invasive species and also good ex-
amples of nonnative food sources that are now deeply
rooted in the local culture. For example, food products
derived from these species are marketed as typical Patag-
onian cuisine and restaurants label them as “traditional”
dishes (Speziale et al. 2012).
Another example of a nonnative becoming a cultural
icon is the wild horse (Equus caballus) of the American
Southwest. Horses are nonnative, invasive species origi-
nally introduced by Spanish explorers to facilitate trans-
port but are so deeply rooted in American culture and
lore that control of their populations is nearly impossi-
ble, and eradication unthinkable. This nonnative species
is so well loved that there are even federal laws to pro-
tect its herds. The Wild Free-Roaming Horses And Burros
Act Of 1971 states “That Congress finds and declares that wild
free-roaming horses and burros are living symbols of the his-
toric and pioneer spirit of the West; that they contribute to the
diversity of life forms within the Nation and enrich the lives of
the American people;...”(Public Law 92–195). These ex-
amples show that once a species gains cultural value, it
can be protected and treasured by the locals even if it is
nonnative and invasive.
There may be a fine line between promoting consump-
tion of a species and incorporating it into local culture. Af-
ter a species becomes widely used it may become part of
the culture, as has happened to many nonnative species
(see Figures 1A and B). Also, when a species is appre-
ciated or is a valued resource, it seems to matter little
how much ecological damage it causes. Human pets, like
cats (Felis catus) or dogs (Canis familiaris), demonstrate this
point, because they can have huge ecological effects, but
in many cases plans to control or extirpate populations
are impractical. Therefore, by promoting the use of non-
native species, we may give them a market value and un-
intentionally promote their incorporation into the local
culture, reducing the chance of success of future man-
agement programs.
There may be fundamental differences between species
originally introduced as a food sources (e.g., fish, wild
boar) and species introduced accidentally or for noncon-
sumptive reasons. People may be less likely to incorporate
Figure 1 Photographs of invasive species products. Examples of products
currently marketed for consumption, as a way to control their populations:
(A) kudzu (Pueraria montana) jelly, garlic mustard (Alliaria petiolata)pesto,
and lionfish (Pteris volitans). Examples of products currently considered a
local delicacy, with no intention of using harvest as a means of controlling
the populations: (B) honey (from Apis melifera) from California, smoked
trout (Oncorhynchus mykiss) from Patagonia, and coffee (Coffea indica)
from India. Photographs credits: R. Poplin, R. Vidal-Russell, and M. A.
Nu ˜
nez.
into their culinary cultures nonnative species not intro-
duced as food sources. Many of the examples of species
that are now incorporated in local cultures (e.g., Figure
1B) were originally introduced for food production, so it
can be expected that they became preferred food items.
However, even foreign or novel food items can gain pop-
ularity and cultural staying power. Studies on food neo-
phobia, the fear of new foods, tell us that there are ways
to overcome people’s reluctance to try new food items.
Constant exposure to an item, association of the new food
with positive attributes (e.g., conservation aids or good
health), and ample advertisement can be effective in in-
corporating new food items (Shepherd & Raats 2006). For
an invasive management program based on human con-
sumption to work, many people must find the nonnative
appealing enough to consume. Therefore a successful gas-
tronomy program must entail incorporation of the species
into people’s food preferences, which if successful, would
lead to the incorporation of the exotic into the local cul-
ture. This may not be the case for invasive species that
are rare or found only in few locations owing to a re-
cent introduction, but may be the case for species that
are abundant and widespread.
A way to avoid the incorporation of a problematic
species into a local culture may be based in how the
species is marketed. A constant reminder to consumers
and collectors that the goal is to decrease population
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M. A. Nu ˜
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size or to eradicate the species because of environmental
problems that they generate can be key to avoiding unin-
tended consequences. If people are not reminded of the
overall goal it may be easier for the species to be incor-
porated into the local culture, to the point of becoming
a staple item on the menu of local restaurants (as with
deer, fish, and wild boar in Patagonia).
Discussion: recipes for success
Eating invader campaigns have several benefits; primar-
ily, they can increase public awareness of invasive species
issues and potentially help detect new populations. Also,
there is ample evidence that humans can reduce popula-
tion sizes of many invasive species by eating them. This
may be especially attainable when the population size is
low, as in the case of recent nonnative species introduc-
tions. Thus, if many people decide to control a species by
eating it, this may be more successful when the species
is rare, at the early stages of an invasion, rather than
when a species is very abundant, at later stages. Pro-
grams based on gastronomic use can also be good com-
plements to other programs, such as volunteer programs
on mechanical removal of invasive species, generating a
stronger combined effect. However, despite the poten-
tial benefits, managers deciding to implement this type of
project should be cautious, because these programs may
have unintended negative consequences.
If managers aim to decrease an invader’s population
through harvest, one of the first steps should be to under-
stand fully the demography of the species. Matrix popula-
tion models provide an effective tool for targeting the ap-
propriate life stage that will cause the largest decrease to a
population’s overall growth rate. These models have been
used to direct management strategies, including selecting
the appropriate life stage to target for management of in-
vasive plants and animals (Ramula et al. 2008; Barbour
et al. 2011). These same techniques should be employed
to test how harvest of edible life stages will affect the tar-
get species’ population growth rate.
How to market the target invasive species may be
fundamental. It may be good to remind consumers and
restaurants that the goal is to decrease population size
of the species and not to make it a staple item on the
menu. Otherwise it will not take too long for people
to start managing for high populations, as has occurred
in some regions with invasive species (Lambertucci &
Speziale 2011). Also, an aspect that may be important
to consider when presenting nonnatives as new items
for human consumption is conservatism of human food
habits. People are inherently conservative in food prefer-
ences and cuisine, and they have a general tendency to
dislike new foods (Rozin & Vollmecke 1986; Shepherd &
Raats 2006). This intrinsic conservatism of people’s taste
could be problematic because the target invasive species
may not be preferred and it may be difficult to encour-
age consumption. This barrier may not be insurmount-
able (see above), but it is formidable. For species like cod
that have been part of the culinary culture for centuries,
it may be easier for humans to affect their population size
through harvest. However, when species are foreign to
the general public, like kudzu or nutria (also know as
river rat), it might be harder to introduce them as food
items.
Not promoting the cultural incorporation of the non-
natives species may be particularly hard to achieve. If a
food item becomes locally attractive, a campaign to con-
trol its population to keep low numbers or to eradicate it
may be controversial (Nu ˜
nez & Simberloff 2005). Man-
agement programs that aim to use nonnatives as food
sources may want to focus on the beneficial outreach as-
pects, because they are likely to gain widespread atten-
tion. Also, not promising control or eradication success
(especially without demographic models that support this
outcome) seems to be especially important. Failed man-
agement campaigns can stoke citizen frustration with all
nonnative control programs and may lead to the assump-
tion that nothing should or can be done to control non-
native species (e.g., Davis et al. 2011).
A number of positive aspects are associated with the
goal of using invasive species as a culinary resource. How-
ever, it is important to remember that sometimes doing
nothing (do not eat them) may be better than promot-
ing their incorporation into the local culture or creat-
ing a market that can be a problem for future manage-
ment programs. Decisions to start or maintain a program
based on human consumption of an invasive species as a
way to control it should arise by carefully considering the
potential benefits and problems that the program could
produce.
Acknowledgment
The authors acknowledge the three anonymous review-
ers for their important comments on this manuscript.
References
Aguilar, A., Banks, J.D., Levine, K.F. & Wayne, R.K. (2005)
Population genetics of northern pike (Esox lucius)
introduced into Lake Davis, California. Can. J. Fish. Aqua.
Sci., 62, 1589–1599.
Baldwin, J. (1999) Kudzu Cuisine: festive recipes to delight the
adventrourous and intrigue the skeptical. Suntop, USA.
Barbour, A.B., Allen, M.S., Frazer, T.K. & Sherman, K.D.
(2011) Evaluating the potential efficacy of invasive lionfish
(Pterois volitans) removals. PLoS ONE, 6, e19666.
Conservation Letters 5(2012) 334–341 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 339

Eating invasive species M. A. Nu ˜
nez et al.
Barclay, E. (2011) In A fish-eat-fish world, order asian carp
and lionfish to save the rest. National Public Radio,URL:
Available from: http://wwwnprorg/blogs/health/2011/07/
07/137674792/in-a-fish-eat-fish-world-order-asian-carp-
and-lionfish-to-save-the-rest. Accessed 20 November 2011.
Bonney, R., Cooper, C.B., Dickinson, J. et al. (2009) Citizen
science: a developing tool for expanding science knowledge
and scientific literacy. Bioscience,59, 977–984.
Boudreaux Bodin, G. (1998) ”COOKIN’ ALIVE”—Save Our
Wetlands, Eat Louisiana Nutria. USDA Press Release,
Available from: http://wwwnwrcusgsgov/releases/
pr98 116htm. Accessed 21 November 2011.
Burdick, A. (2006) Out of Eden: An odyssey of ecological invasion.
Farrar Straus & Giroux, New York, NY.
Callaway, R.M., Thelen, G.C., Rodriguez, A. & Holben, W.E.
(2004) Soil biota and exotic plant invasion. Nature, 427,
731–733.
Crouse, D.T., Crowder, L.B. & Caswell, H. (1987) A
stage-based population model for Loggerhead sea turtles
and implications for conservation. Ecology, 68, 1412–1423.
Davis, M., Chew, M.K., Hobbs, R.J. et al. (2011) Don’t judge
species on their origins. Nature, 474, 153–154.
Diaz-Betancourt, M., Ghermandi, L., Ladio, A.,
Lopez-Moreno, I.R., Raffaele, E. & Rapoport, E.H. (1999)
Weeds as a source for human consumption. A comparison
between tropical and temperate Latin America. Revista De
Biologia Tropical, 47, 329–338.
Elmendorf, S., Byrnes, J., Wright, A., Olyarnik, S., Fischer,
R. & Chamberlin, L. (2005) Fear and fishing in Lake Davis.
Flag in the Ground Productions, Davis, California USA.
Food & Water Watch. (2011) Smart Seafood Guide 2011.
Food & Water Watch, Available from: http://wwwfood
andwaterwatchorg/fish/seafood/guide/. Accessed 22
November 2011.
Franke, J.M. (2007) The invasive species cookbook: conservation
through gastronomy. Bradford street Press, Wauwatosa, WI.
Fujimori, L. (2003) With knives and arrows, avid hunters
control pigs. Honolulu Star Bulletin, May 4, Available from:
http://archivesstarbulletincom/2003/05/04/news/story
2html. Honolulu. Accessed 21 November 2011.
Halliday, T. (1980) The extinction of the passenger pigeon
Ectopistes migratorius and its relevance to contemporary
conservation. Biol. Conserv., 17, 157–162.
Hierro, J.L., Villarreal, D., Eren, O., Graham, J.M. & Callaway,
R.M. (2006), Disturbance facilitates invasion: the effects
are stronger abroad than at home. Am. Nat., 168, 144–156.
Holdaway, R.N. & Jacomb, C. (2000) Rapid extinction of the
Moas (Aves: Dinornithiformes): model, test, and
implications. Science, 287, 2250–2254.
IPANE. (2011) Invasive species recipes. Invasive Plant Atlas of
New England Available from: http://nbii-ninciesincolum
biaedu/ipane/weedwisdom/recipehtm. Accessed 21
November 2011.
Johnson, D.V. (1996) Palms: Their conservation and sustained
utilization. IUCN, Cambridge, UK.
Johnson, B.M., Arlinghaus R., Martinez P.J. (2009) Are we
doing all we can to stem the tide of illegal fish stocking?
Fisheries,34, 389–394.
Jordan, R.C., Gray, S.A., Howe, D.V., Brooks, W.R. &
Ehrenfeld, J.G. (2011) Knowledge gain and behavioral
change in citizen-science programs. Conserv. Biol., 25,
1148–1154.
Keane, R.M., Crawley, M.J. (2002) Exotic plant invasions and
the enemy release hypothesis. Trends Ecol. Evol., 17,
164–170.
Klironomos, J.N. (2002) Feedback with soil biota contributes
to plant rarity and invasiveness in communities. Nature,
417, 67–70.
Kolar,C.,Courtenay,W.,Jr.,Nico,L.,Hubert,W.&Quist,M.
(2010) Managing undesired and invading fishes. Pages
213–259 in H. WA, Q. MC, editors. Inland fisheries
management in North America. American Fisheries Society,
Bethesda, MD.
Lambertucci, S.A. & Speziale K.L. (2011) Protecting invaders
for profit. Science, 332, 35–35.
Lehrer, J.M., Brand, M.H. & Lubell, J.D. (2006) Tackling a
thorny issue. Am. Nurseryman, 8, 30–36.
MAEPPC. (2011) Mid-Atlantic Exotic Pest Plant Council,
Eat those Invasive Plant Pests, Available from: http://
naturaljournal.blogspot.com/2009/01/eat-those-invasive-
plant-pests.html. Accessed 20 November 2011.
MAIPC. (2011) Eat those Invasives! Mid-Atlantic Invasive
Plant Council, Accessed online: http://ma-eppcorg/weed
recipeshtml. Accessed 24 November 2011.
McCloud, C. & Solano, S. (2011) Target Hunger Now! Progam
features Asian Carp. Illinois Department of Natural Resources
Press Release, Available from: http://wwwdnrillinoisgov/
news/Pages/TargetHungerNow!ProgramFeatures
AsianCarpaspx. Accessed 22 November 2011.
McGraw, J.B. (2001) Evidence for decline in stature of
American ginseng plants from herbarium specimens. Biol.
Conserv., 98, 25–32.
Minsky, D. (2011) Adobo wild boar, lionfish tacos, and
snakehead stew: five Edible South Florida invasive species.
Miami New Times Food Blog. Available from: http://blogs.
miaminewtimes.com/shortorder/2011/11/adobo wild
boar lionfish tacos.php. Accessed 22 November 2011.
Murawski, S.A. (2010) Rebuilding depleted fish stocks: the
good, the bad, and, mostly, the ugly. ICES J. Mar. Sci., 67,
1830–1840.
NOAA. (2011) Filleting the Lion. NOAA Weekly News,
National Oceanic and Atmospheric Administration.
Nogueira, S.L.G., Nogueira, S.S.C. & Fragoso, J.M.V. (2009)
Ecological impacts of feral pigs in the Hawaiian Islands.
Biodivers. Conserv., 18, 3677–3683.
Nogu´
es-Bravo, D., Rodr´
ıguez, J., Hortal, J., Batra, P. &
Ara ´
ujo, M.B. (2008) Climate change, humans, and the
extinction of the woolly mammoth. PLoS Biol., 6, e79.
Nu ˜
nez, M.A. & Simberloff, D. (2005) Invasive species and the
cultural keystone species concept. Ecol. Soc., 10,1–4.
340 Conservation Letters 5(2012) 334–341 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc.

M. A. Nu ˜
nez et al.Eating invasive species
Pasachnik, S.A., Fitzpatrick, B.M., Near, T.J. & Echternacht,
A.C. (2009) Gene flow between an endangered endemic
iguana, and its wide spread relative, on the island of Utila,
Honduras: when is hybridization a threat? Does
hybridization threaten an endangered iguana? Conserv.
Genet., 10, 1247–1254.
Ramula, S., Knight, T.M., Burns, J.H. & Buckley, Y.M. (2008)
General guidelines for invasive plant management based
on comparative demography of invasive and native plant
populations. J. Appl. Ecol., 45, 1124–1133.
Rapoport, E., Raffaele, E., Ghermandi, L. & Margutti, L.
(1995) Edible weeds: a scarcely used resource. Bull. Ecol.
Soc. Am., 76, 163–166.
Reed, K.D. (2002) Culinary Kudzu: recollections and recipes from
growing up southern. Pecan Street Press, USA.
Richardson, D.M. (1998) Forestry trees as invasive aliens.
Conserv. Biol., 12, 18–26.
Rosenthal, E. (2011) Answer for invasive species: put it on a plate
and eat it. Page A14. The New York Times, New York.
Rozin, P., Vollmecke T.A. (1986) Food likes and dislikes.
Annu. Rev. Nutr., 6, 433–456.
Schofield, P.J. (2009) Geographic extent and chronology of
the invasion of non-native lionfish (Pterois volitans
[Linnaeus 1758] and P. miles [Bennett 1828]) in the
Western North Atlantic and Caribbean Sea. Aqua.
Invasions.,4, 473–479.
Shepherd, R. & Raats, M. (2006) The psychology of food choice.
CABI, UK.
Simberloff, D. (2001) Managing established populations of
introduced species. Pages 269–278 in R. Claudi, O.
Hendrickson, H. Ottens, editors. Alien invasive species: A
threat to Canadian biodiversity. Natural Resources Canada,
Canadian Forest Service, Ottawa.
Simberloff, D. (2003) Eradication—preventing invasions at
the outset. Weed Sci., 51, 247–253.
Simberloff, D., Nu ˜
nez, M.A., Ledgard, N.J. et al. (2010) Spread
and impact of introduced conifers in South America:
lessons from other southern hemisphere regions. Austral.
Ecol., 35, 489–504.
Speziale, K., Lambertucci, S., Carrete, M. & Tella, J. (2012)
Dealing with non-native species: what makes the
difference in South America? Biol. Invasions, DOI:
10.1007/s10530-011-0162-0.
Thresher, R.E. (1996) Physical removal as an option for the
control of feral carp populations. Pages 58–73 in J. Roberts,
R. Tilzey, editors. Controlling carp: exploring the options for
Australia. CSIRO Land and Water, Griffith, Australia.
USDA. (2010) Census of Horticultural Specialties (2009). Vol.
3, pp. 595. United States Department of Agriculture,
Washington, DC.
Veitch, C. & Clout, M. (2001) Human dimensions in the
management of invasive species in New Zealand. Pages
63–71 in J.A. McNeely, editor. The Great reshuffling human
dimensions of invasive alien species IUCN, gland. Switzerland
and Cambridge, UK.
Vozella, L. (2011) Maryland chefs want to put snakeheads on
the menu: In the fight against invasive species, ‘if you can’t
beat ‘em, eat ‘em’ they say. The Baltimore Sun July 19, 2011
Available from: http://articlesbaltimoresuncom/2011-07-
19/entertainment/bs-ae-snakehead-dinner-20110719 1
invasive-species-snakeheads-native-fish-populations.
Accessed 20 November 2011.
Walton, C.K. (2011) Chefs cooking up new ways to prepare
venomous lionfish. Foxnewscom, Available from:
http://www.foxnews.com/leisure/2011/10/30/lionfish-
onmenu-demonstrates-creativity-environmental-
conscience. Accessed 20 November 2011.
Yonekura, R., Kariya, T., Fujii, R. et al. (2007) Control of a
bluegill population by angling. Nippon Suisan Gakkaishi, 73,
839–843.
Conservation Letters 5(2012) 334–341 Copyright and Photocopying: c
2012 Wiley Periodicals, Inc. 341