Oct 31

Friday Feast! October 31, 2014

Eating invasive species news and notes from around the internet!

Oct 17

Friday Feast! October 17, 2014

Eating invasive species news and notes from around the internet!

Oct 10

Friday Feast! October 10, 2014

Eating invasive species news and notes from around the internet!

Sep 26

Friday Feast! September 26, 2014

Eating invasive species news and notes from around the internet!

Sep 19

It be Talk Like a Pirate Day, eat some invasive booty!

Ahoy maties!  Today be National Talk Like a Pirate Day, and me thinks thar bein’ no better way to be celebratin’ than feastin’ on some invasive booty!  Try slippin’ these briney rations down your gullet, or walk the plank!


Green crab

Chinese mitten crab

Now, where be the invasive grog?


Sep 15

Try to guess these 11 recommendations for harvesting invasive species

Harvesting invasive species receives some scientific guidance, and perhaps a place in the manager’s toolbox, this month with the publication of Pasko and Goldberg’s “Review of harvest incentives to control invasive species” (pre-pub proof) in the September issue of the scientific journal, Management of Biological Invasions.

The blind eating the blind, lack of guidance for harvests

Eating invasive species has received a lot of attention from the media over the last few years probably as a combination of 1) being kind of weird and 2) feeling like a good idea.  It’s that second reason that has kept many natural resource managers and conservationists on the sidelines of the conversation.  What has felt like a good idea for resource management in the past has often turned into something really bad.  For example:  kudzu, cane toads, and Nile perch are cases of well-intentioned introductions gone awry. That is, managers and conservationist may be a bit trigger-shy around tactics that just *sound* good. Indeed, the limited offerings in the scientific literature pertaining to harvesting invasive species urge caution due to the potential unintentional consequences of developing market or social values for invasive species (Nunez et al 2012).  The biological and economic limitations of harvests, such as for Asian carp (Tsehaye et al 2013), make it clear that harvests aren’t a silver-bullet solution.  However, there is recognition that harvests could play a part in larger control and conservation measures.  Guidance for when and how to incorporate harvests into invasive management schemes has been missing; a new article by Pasko and Goldberg lays out the possible place for harvests of invasive species within a holistic, adaptive management framework.

11 Recommendations for harvesting invasive species

Pasko and Goldberg review the many issues that surround the potential benefits and risks of harvesting invasive species, and they conclude with the following recommendations to help maximize the success of harvest incentive programs:

 1. Define the management plan and objectives

Almond tilapia raw ingredients

Defining a plan and objectives is a lot like getting all your ingredients in order before you start cooking, like this Almond tilapia.

The conservation goals of harvesting invasive species are obscure in many contexts, yet defining success is the first step. There’s no universal goal for all invasivores, and total eradication is far too lofty.  Setting realistic goals will be an important part of integrating harvests into management.

2. Understand the costs


Matt and Andy enjoy mealworm Rice Krispies treats

There’re costs to harvesting invasive species, more than just putting your mouth where your mouth is.  Matt and Andy enjoy meal-worm Rice Krispies treats

Harvesting invasive species may seem like a win-win, and under ideal circumstances perhaps sales and recovery of ecosystem services could increase total social value.  But it won’t be free.  Any control program will have administrative costs that may be difficult to recoup.

3. Understand target species’ population dynamics

Models of population dynamics can be simple, like this logistic model,  but detailed models tailored to specific species and populations will be more successfull

Models of population dynamics can be simple, like this logistic model, but detailed models tailored to specific species and populations will be more successful.

The population dynamics of an invasive population determine how- or if- the population will respond to harvesting effort.  In some cases, harvests could actually increase population growth.  Understanding population dynamics may prevent such unintended consequences and help determine how much populations should be reduced to achieve management goals.

4. Consider risks to human health and safety

Phragmites young shoots

Phragmites may sequester metals and other toxins, which could pose health risks if consumed regularly and/or in large quantity.

Some risks are obvious; for example, lionfish have poisonous spines.  Others are not so obvious.  Many species have high toxic loads, like sea lamprey in the Great Lakes.

5. Evaluate potential ecological outcomes

NOAA & Great  Lakes Fishery Commission Food Web

NOAA & Great Lakes Fishery Commission food web exemplifies the complex interactions linking many components of ecosystems that may change given alterations in invasive populations.

Invasive species, despite being undesirable by definition, often play substantial roles in the ecosystems which they have invaded.  Understanding the “dominoes” to fall following removal is important.  For example, while alewife are an invasive species in Lake Michigan, they are vital forage for salmon, which are highly desirable.

6. Monitor for unintended outcomes


One way to monitor for unintended consequences.

The complex ecological interactions of ecosystems makes unforeseen undesirable responses to harvest likely.  For example, when cats where eradicated from Macquarie Island, the population of rabbits grew rapidly and with devastating results to the local ecosystem (Bergstrom et al 2009, Journal of Applied Ecology).

7. Prevent re-introduction

Stop the Spread of tilapia

Andy standing guard to prevent further species introductions.

Harvesting programs will be ineffective if new target individuals (perhaps new species) are able to regain access to the ecosystem.  Prevention, monitoring, and rapid response to new introductions will be required to prevent re-establishment.

8. Incorporate adaptive management

Andy Invasivoring a Phragmites shoot

If a management plan is a recipe, adaptive management is tasting and flavoring a dish as you cook.

Adaptive management follows the principal that effective management requires periodic assessment of the invasive population and the recovery of ecosystem service in order to update management methods as new information becomes available.

9. Conduct outreach

Pulled Feral Pork Sandwiches

Outreach?  You mean like at our Invasivore tailgate?

Public understanding and support of invasive species management will make a project easier to manage.  Besides, someone’s got to eat all this garlic mustard queso.

10. Restore impacted areas


Phragmites australis at Potato Creek State Park

Okay, once all this phragmites is gone, what’s going to grow here instead?

Pulling up a forest of garlic mustard is going to leave behind a mess.  More importantly, just removing an invasive population doesn’t mean that native species and ecosystem services will return on their own.  Management should include a clear idea about what services are desired from a target area, and how best to achieve them.

11. Determine appropriate points for government intervention

A trailer full of Asian carp at the Redneck Fishing Tournament

A trailer full of Asian carp.

More than just funding projects, governments can provide outreach and education, as well as possible regulatory oversight. For example, adapting appropriate hunting regulations or monitoring food safety.

Sep 12

Friday Feast! September 12, 2014

Eating invasive species news and notes from around the internet!

Sep 08

Sometimes a net is mightier than a fork!

This post is a guest contribution from Sean Ryan and Meredeth Doellman of The Pieris Project. Read on to see how you can become involved with some exciting citizen science!

Pieris rapae

photo by Flikr user Dendroica cerulea through a Creative Commons license

Invasivore.org has had fun developing novel ways to engage the public with invasive species, but what do you do with those invasives that aren’t so filling? Answer: Put down your fork and pick up your butterfly net! (at least when the invasive is a butterfly.) Invasive species are not only tasty, but can be useful to study how organisms adapt to new environments and climate change. For example, by understanding how an invasive butterfly – the cabbage white (Pieris rapae) – has adapted as it spread across North America, folks at The Pieris Project hope to gain insights as to how other species may adapt to similar environmental changes. The Pieris Project is a partnership with the public (you!) to collect this invasive butterfly from across the US, and soon the world!

The cabbage white is believed to have invaded the entire US, most of North America, and many other parts of the world; it’s pretty much everywhere but Antarctica. The butterflies were introduced to North America from Europe in the late 1800s and spread from eastern Canada across North America within only a few decades. The caterpillars feed on many agricultural crops (plants in the mustard family such as broccoli, cabbage, kale, and Brussels sprouts), which is in part why they have been able to invade many parts of the world; these invaders are eating our food!

This year, the Pieris Project wants to collect at least 20 butterflies from each US state and as many countries from across the world as they can.  Helping them reach this goal is easy, partly because these butterflies have invaded everywhere, including your backyard! To get involved is easy: visit pierisproject.org to learn how to catch them, where to send them, and what cool things we hope to learn about them. By catching a few butterflies from your hometown, you can join the many citizen scientists that are helping to use this invasive species to learn how other native species of butterflies will respond to changes in their environment, such as climate change, habitat destruction, and changes in land-use. Thanks for your help, and we wish you happy hunting!

Aug 29

Friday Feast! August 29, 2014

Eating invasive species news and notes from around the internet!

Aug 25

Notes from the road: spotlights on leading plant invasive species research

HobanInvasivore Sean Hoban recently attended the annual meeting of the Botanical Society of America in Boise, Idaho, which featured a session an afternoon session on some recent studies in plant Invasion Biology. Six researchers presented their latest ecological and genetic findings, from the interactive effects of Amur honeysuckle and white-tailed deer to hybridization among multiple species of knapweed. Overall, the studies give us better knowledge of how and why some species invade, as well as how invaders affect the invaded communities. Here, Sean highlights some interesting findings from each presentation.

Erica Case from UC Davis talked about impacts of goatgrass on the fragile serpentine grasslands of California. These unique habitats only make up 1-2% of California land area but have 10% of the total species! Unfortunately these habitats are being invaded, partly due to increasing use of off-road vehicles, which disperse seeds, and gopher activity, which disturbs the soil and opens a place for the introduced seeds to take hold. Erica talked about how species might be lost from certain local habitats due to invaders, but sometimes they persist in other local habitats. This rare persistence prevents their overall extinction. Her research will help understand what factors help natives persist in some locations but not others.

Next, Gina Marchini from Portland State University presented experimental results working on the invasive bunchgrass Brachypodium sylvaticum (slender false brome), which is native to Western Europe but is invading the Northwest United States. Interestingly, the plant receives much less rain in its invasive locations, so Gina’s aim is to determine exactly what factors allow it to tolerate higher this greater dryness. She found, among other results, that invading individuals can maintain their leaf shape better and their cells are also more elastic than the native source populations, allowing them to keep better hydrated during drought. This drought tolerance ability may be partly due to evolution during the invasion process.

Then, Peter Guiden and Jessica Peebles-Spence from Miami University gave a pair of talks on white-tailed deer and Amur honeysuckle. Using 40,0000 hours or radio-tracking data, Peter showed evidence that deer can eat and then transport honeysuckle seeds up to 8 kilometers. He also found that  31% of pellets germinated even after passing through the deer’s digestive system. Thus, invasivore deer could help disperse, intensify and spread the invasion. Jessica was interested on how the native forest will recover if deer and/or honeysuckle were excluded from plots. She found higher species richness in plots where both of thse invaders were excluded, though it took several years for this native plant community to begin to recover.

The last two talks used genetic tools for different uses. Tomáš Závada from University of Massachusetts Boston used genotypes to determine how many introductions occurred of two knapweed species on Nantucket Island, and to identify hybrids. Lastly, Hannah Marx of the University of Idaho used very large genetic datasets and large computational power to determine how different combinations of species can develop into a community. Specifically she was interested to determine whether evolution of traits that help a species escape competition might be an important mechanism that helps invasive species establish.

Throughout the conference there were many other presentations, posters and discussions on various aspects of plant biology. The next Botany conference will be in Edmonton, Canada in July 2015.

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