A sampling of eating invasive species news and notes from around the internet.

This week’s most interesting read: “How cooking turned humans into an invasive species”

Hairy Bittercress from The 3 Foragers and Wildman Steve Brills

The Lion King I never get tired of hearing about harvesting lionfish…now we hear that traps work in addition to spear fishing.

The endangered Lake Erie water snake benefits from eating invasive gobies.

The April 1 enforcement date looms on new feral swine regulation in Michigan.

The idea of commercial crayfish harvest in Lake Tahoe is picking up steam.

Lissa Strohecker for Maui News makes a eating invasive species  resolution.

An edible invader, the red swamp crayfish, is eating its way across Africa.

Sharpshooters considered for deer damage control- Oh what shall they do with them all?

Michigan is drafting A Guide to Invasive Plant Species of Michigan- sure to include eatable invasives from the picture of garlic mustard on the cover.  Consider sending them a suggestion to include comments about which are edible - campbellsl@michigan.gov

A debate is stirring in Ireland about whether to consider the Wild Boar invasive- or a reintroduction of a long-missing native.

Funding to assist landowners in controlling invasive species of flora and fauna in Massachusetts- can we use it buy a new range?

Eating invasive species news and notes from around the internet

Our friend Chef Chad Wells talks about eating invasive snakehead

Competitions in Florida here and here target invasive lionfish.

Turning Asian carp into fertilizer in Illinois

Girl Scouts can now earn their locavore merit badge- next up, an invasivore merit badge?

Kiera Butler of Mother Jones tries her hand at cooking invasive plants.  With tasty results!  And here are a few edible invasive species in Florida.

We love stories about nonhuman invasivores- like this one from Neatorama

Eating invasive crayfish in Oregon?  Yes, please.

Several people sent me great links for the round-up this week, thanks!  And keep them coming.  This week, I get taunted by Garlic Mustard Ice Cream.

Tuesday, May 31

Insect Eating Invasive Plant in the Everglades

Sunday, June 5

Allen Afield: Crappies are invasive, but they’re great fun, food

Tuesday, June 7

Making The Best Out Of Invasion, Missouri Shop Makes Cicada Ice Cream- oh Garlic Mustard Ice Cream…why must you tease me so?

Wednesday, June 8

I got an email from Conservation Biologist Joe Roman this week, and I’m happy to pass on some really great articles of his from a few years ago.  Try the Nutria, Wild Boar and crawfish egg rolls.  Follow up with the Kudzu Sorbet (dang-it GMIC)

Bon Appetit: Ecologists are devising invasive species control strategies that would make Julia Child proud.

Eat the Invaders! As marauding hordes of invasive species devour heaping helpings of the North American landscape,
we offer some recipes that might help turn the tables.

also on the 8th-

City Says Baaaaaa-humbug To Invasive Plants

San Diego County’s Wild Pig Problem- Oddly Familiar

Friday, June 10

Mississippi flooding may have spread invasive fish

Michigan’s Canned Hunt Ranches Fight to Keep Exotic Swine Legal

Australia: Killing Camels for Carbon Credits?- not exactly eating, but a clever way to recoup lost costs?

Weekly round-up of eating invasive species news and other tidbits from around the internet.  Overall a quiet week, but we got a chance to talk with Dr. Holly Menninger for her radio show Science Cabaret on Air, and you’ll be able to hear that interview next Sunday, June 12 at 7pm EST.

Thursday, June 2

Invasive crayfish has claws

The frogfish is the world’s most efficient invasivore- Challenge accepted

Saturday, June 4

The Lizard King- Good story about fellow invasivore George Cera and his campaign against Iguanas in Florida.

We’re honored to share this tasty crayfish recipe from Dr. Charles Goldman, one of the fathers of modern limnology!  Dr. Goldman has spent over 40 years conducting research on Lake Tahoe, home to today’s featured ingredient, the signal crayfish.

Mini-Profile: Signal Crayfish

Signal crayfish (Pacifasticus leniusculus) are native to western North America, living in freshwater lakes and streams from California to British Columbia.  Invasive populations occur in at least 25 countries in Europe as well as Japan.  Like Louisiana and rusty crayfish, introduced signal crayfish have voracious appetites and can greatly reduce invertebrate and plant populations and can outcompete and displace native crayfish.

Recipe: Lake Tahoe Crayfish Boil

Ingredients

10 liters water

1 liter dry white wine (recommended: Sauvignon blanc or Muscadet)

2 large onions, chopped

4 lemons (juice plus 2-3 whole squeezed fruit)

1 cup fresh parsley

1 tbsp salt

1 tbsp black peppercorns

0.5 oz dill weed

4 lbs whole crayfish

Directions

Bring water to a boil before adding all ingredients except crayfish.  Boil until onions are soft, then add crayfish and maintain at a boil for about 10 minutes or until crayfish are bright red.  Remove from heat and let crayfish cool in the water.  The longer crayfish soak,the more flavorful they will become.  Dr. Goldman even recommends letting the crayfish steep overnight for maximum flavor.  Whenever you are ready, simply peel* and enjoy!

*If you need a refresher, instructions for peeling crayfish can be found here.

Boiled signal crayfish. Photo credit: Marion Wittmann

Just as the Louisiana crayfish is honored with festivals and feasts, the native “noble” crayfish (Astacus astacus) is enthusiastically consumed in Sweden during parties known as kräftskivas.  It seems native European crayfish have been consumed too excessively, as the American signal crayfish (Pacifastacus leniusculus) has now been introduced as a food source in response to decreasing numbers of noble crayfish.

To honor the cultural celebrations of crayfish around the world, today’s recipes describe two popular ways to boil them up.  Imagine the good you can do by emphatically eating crayfish that threaten your regionally native species!

Boiled Rusty Crayfish served "Northwoods" Style (arranged in a minnow trap); Photo Credit: Grace Loppnow

Ingredients: Cajun Style Crayfish Boil

5 quarts water

1 medium onion, cut into wedges

1 lemon, cut into wedges

6 cloves garlic, peeled and coarsely sliced

2 tablespoons cayenne pepper

6 tablespoons salt

2 lbs whole crayfish

Ingredients: Swedish Style Crayfish Boil

2.5 quarts water

6 tablespoons salt

1 teaspoon sugar

Generous amount of dill (fresh crowns preferred)

2 lbs whole crayfish

Directions

For either recipe, bring water to a boil before adding all ingredients except crayfish*.  Boil for 10 minutes to get the flavors acquainted.  Next, add live crayfish and boil for an additional 7 minutes.  Crayfish can be cooked in several batches, though you may want to refresh with more salt and spices.

*For a more authentic Cajun experience, you can also boil small red potatoes and corn (shucked, on the cob cut in thirds).  Add small red potatoes to the boiling boil 10 minutes before the crayfish, and add corn at the same time as the crayfish.

This recipe comes to you courtesy of guest contributor Ashley Baldridge.  Ashley is a PhD student at the University of Notre Dame whose research focuses on the impacts of invasive rusty crayfish in Wisconsin and Michigan.

The rusty crayfish (Orconectes rusticus) is native to the Ohio River basin in the United States.  It has been distributed to other areas around the country, most likely as unused bait released by fishermen.  It arrived in Wisconsin in the 1960’s and has since established itself as a nasty invader throughout the upper Midwest and can also be found in New England and some western states (full map here).

A jump from Ohio to Wisconsin may not sound like a big deal.  People do it all the time.  However, the rusty crayfish occupies streams in its native Ohio range and behaves quite differently when it settles into lakes.  Rusty crayfish can reach much higher densities than resident crayfish species because they out-compete other crayfish for shelter and food and are more aggressive with predatory fish, which makes them less likely to be eaten.  Rusty crayfish are capable of altering the character of a lake when they reach high densities; they clear-cut aquatic plants, consume large numbers of snails and aquatic insect larva, and even impact the fish community.

Rusty Crayfish, Photo Credit: Ashley Baldridge. For identification, also check out these guidelines from US Fish and Wildlife

Invasive Crayfish: It’s all Relative

I have an affinity for the virile crayfish (Orconectes virilis), perhaps because we are both natives of the upper Midwest.  In my reference frame, the virile crayfish are the modest native species that are constantly bullied by the feisty rusty crayfish.  My values were challenged when I discovered that virile crayfish is a scorned invader in Europe and several US states.

This story highlights the diversity of crayfish and how a species can be benign, even threatened, in its home range while being TOO successful in another.  There are over 500 species of crayfish worldwide, 75% of which come from North America.  Many of these species have very specialized and limited ranges.  Some species, such as the rusty and Louisiana crayfishes, are able to do very well in an expanded range, while other species are more vulnerable to changes to their familiar conditions.  On a final note, it strikes me as ironic that the primary threat to native crayfish diversity is the introduction of new crayfish.

The silver lining here is that many different invasive crayfish make tasty treats for invasivores.  Tomorrow, I’ll be sharing two variations on a crayfish boil recipe that are sure to impress.

This species profile comes to you courtesy of guest contributor Ashley Baldridge.  Ashley is a PhD student at the University of Notre Dame whose research focuses on the impacts of invasive rusty crayfish in Wisconsin and Michigan.

Crayfish Collection

Checking a crayfish trap in the field

There are many ways to catch a crayfish ranging from fishing with bait on a line to snorkeling with a hand-net, and everyone seems to swear by their own method.  We recommend baited traps.

We have had considerable success using minnow traps.  Minnow traps are relatively inexpensive to purchase, and instructions on how to build your own trap can also be found online.  Regardless of whether you buy or build your trap, one of the key determinants of your crayfish-catching success is the type of bait used to lure crayfish into the trap. Again, everyone seems to swear by their own preferred bait.  We have seen recommendations ranging from cat food to fish heads, but we have tended to have success with a few ounces of beef liver.

We recommend setting traps in water 1-2 meters deep.  Crayfish like habitats where there is a lot of shelter to be found, so setting traps in rocky areas can increase your crayfish catches.  Because Louisiana crayfish are particularly adept at burrowing in soft sediments, seeking out evidence of burrows in soft sediments can also be a good way to identify areas for successful trapping.  Crayfish are most active at night, so we usually set traps in the evening and harvest the next day.

Preparation

Crayfish are among the easiest invasive species to prepare for human consumption, but while they are alive, watch out for their chelae, or claws.  They sure can pinch!

To prepare crayfish, bring a pot of water to a rolling boil.  Add live crayfish to the water and continue boiling for 15 minutes.  After boiling, allow crayfish to cool before handling.  The best meat of the crayfish is in the tail.  As with crayfish cousins, crab and lobster, there are many ways to crack the crayfish shell to reach the meat inside.  Several helpful guides with pictures can be found online (for example, here).  Briefly, start by grasping the crayfish by the head in one hand and tail in the other.  Next, use a twisting motion to rip the tail away from the body.  Finally, pinch the “fins” at the end of the tail to squeeze the meat out, similar to dispensing a tube of toothpaste.  A small fork can also be helpful to pry out more stubborn tail meat.  If all else fails, you can also use a fork or knife and brute force to crack the shell away bit by bit.

Once shelled, boiled crayfish meat can be eaten directly or used as ingredients in other recipes such as the crayfish-spinach-artichoke dip described below.

Ingredients

2 x (8oz) boxes cream cheese

1/2 x (10oz) package frozen spinach

1/2 x (14oz) can artichoke hearts

1/2 cup skim milk

3/4 oz Kraft grated parmesan cheese

1/2 lb crayfish tails, cooked, shelled, and coarsely chopped

Directions

We have suggested 1/2 lb of crayfish tails here, but other seafood dips vary considerably  in their fish-to-cheese ratios, so we encourage you to experiment with different amounts of crayfish to find your preferred taste.  Mix all ingredients together and heat on stovetop- do not boil.  We recommend serving the dip warm in the center of a scooped-out sourdough bread bowl, but this dip is also tasty enjoyed on your favorite cracker or with tortilla chips.

The Weekly Invasivore Round-up compiles our favorite news and blogoshpere items from the week which we think are relevant to Eating Invasive Species. This week is tallow tree, turtles & frogs, more lionfish, Hawaii, crayfish and rock-snot. Invasivore.org even gets a shout-out.

Saturday, Feb 12

Laura Christman: Mellow tallow has a sinister side

The Chinese tallow (Triadica sebifera) is noxious in much of the southern US, but the waxy seed oil can be extracted and used for cooking, soap, and biodiesel.  The leaves may be toxic.

Monday, Feb 14

Eating Frogs and Turtles in California Just Got Easier

California has repealed recent restrictions on importing and selling live animals for human consumption, sometimes resulting in release.  The repeal comes after accusations that the restrictions where racially motivated.  That point is moot however, as the “american” culture imports invasive species left and right, with a very antiquated federal “Lacey Law”, and major trades in reptiles, plants and fish. At least when these turtles etc. do escape into the wild, we know we can eat them.

Tuesday, Feb 15

Local Chefs Do Their Part to Fight Lionfish Invasion

See our lionfish profile for more lionfish.

Wednesday, Feb 16

Hawaiian Biodiversity Loss Driven by Feral Ungulates

“…populations must be managed and controlled at a rate faster than they can reproduce.”

Thursday, Feb 17

Invasive Crayfish May Be Class Pets First

Well, Oregon, this coming week is crayfish week, so listen up.  It’s hard not to wonder if these new invasions aren’t a sign of declining science in public schools.  Instead, it’s actually increasing hands-on science education that lead to this problem which has become an excellent, and potentially delicious, “teaching moment”.

Friday, Feb 18

Invasive Species Threatens Missouri Streams

It’s “rock-snot” or “Didymo” (Didymosphenia geminate) .  But it’s edible, according to grist.

Saturday, Feb 19

Entomophagy, invasivors, and foragers … oh my!

Omnivore, locavore, invasivore: Lenten supper alternatives