A buffet of eating invasive species news and notes from around the internet!

• We recently enjoyed picking autumn olives in northern Indiana.  Elsewhere in the state, the Department of Natural Resources are stepping up eradication efforts.  Maybe we should send along our jam recipe?
• Enjoying Asian Carp burgers in Chicago.
• The fight over sporting swine continues in Michigan.
• The largest Asian clam control effort in history of Lake Tahoe is underway!
• Shout-out to colleagues at our base of operations, the University of Notre Dame, for receiving a grant from the EPA to continue research on genetic detection of invasive species!

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

• Popular Mechanics provides a slideshow of 5 invasive species you should be eating
• More news about the developing invasive crayfish market in Lake Tahoe
• Interesting use of invasive species in Tristan de Cunha in honor of the Queen’s Jubilee
• More coverage of the Nunez et al Conservation Letters article
• A tasty description of a recent invasive species meal including Asian carp, dandelions, and garlic mustard
• Testing a new harvester for collection of Asian clams
• Incredible story of invasive species hitching a ride across the ocean

1 – Because they are hermaphrodites that can self-fertilize, the number of Asian clam (Corbicula fluminea) individuals needed to establish a population

70,000 – Approximate number of eggs produced by an Asian clam each year

3 – Average lifespan (in years) of an Asian clam, although some have lived up to 7!

That’s a lot of clams; we better start eating!  Although they are smaller than the clams you are used to cooking, Asian clams can be an excellent substitute in your favorite clam chowder or other dish.  The next few numbers will lead you to a few recipes to try!

174 – Number of recipes listing clam as an ingredient on Allrecipes.com

688 – Number of recipes on Foodista.com featuring clam as an ingredient

0.08 – Seconds it took us to identify approximately 236,000 results via Google Recipe search for “clam”

Today’s recipe was contributed by Christine Ngai Ryan whose research at the University of Nevada Reno focuses on invasive fish.

The name “three cups” indicates a traditional style of Taiwanese cooking and refers to the three main ingredients of the sauce: soy, rice wine, and oil.  Here, we use the sauce in a recipe featuring the Asian clam Corbicula fluminea, but the “three cups” sauce is commonly used in other recipes featuring ingredients such as chicken, squid, and assorted mushrooms.

Preparation

A helpful guide for collecting and preparing clams can be found here.  One of the most important things to remember when collecting any clams for consumption is that they are filter feeders so do NOT eat clams collected from polluted waters.

Corbicula shell. Photo credit: http://www.jaxshells.org/ascl.htm

Ingredients

2 cups Asian clams, still in shell

3 thick slices of ginger

4 cloves garlic, coarsely chopped

2 Asian chili peppers, coarsely chopped

1 bunch basil, coarsely chopped

2 tablespoons soy sauce

2 tablespoons sesame oil

2 tablespoons rice wine

1/2 tablespoon sugar

1 tablespoon cooking oil

Directions

1.  Combine and warm sesame oil and cooking oil in wok

2.  Over low heat, fry ginger, garlic, and peppers until golden brown and fragrant

3.  Increase to high heat and add clams, soy sauce, rice wine, and sugar

4.  Cover and cook until clam shells open (6-8 minutes)

5.  Remove from heat, stir in chopped basil, and enjoy

What clogs up pipes and costs a billion dollars a year in damages?  Asian clams, Corbicula fluminea, and they’re invading a freshwater habitat near you!

Originally introduced into the United States for from its native Southeast Asian waters by Chinese immigrants for the purpose of consumption, the Asian clam Corbicula fluminea has colonized many waterways in the northern hemisphere since it was first discovered in the Columbia River in Washington state in 1938.  Since then, Asian clams have been introduced or dispersed into most of the United States.  A recent study showed that climate change is a potential culprit for this rapid invasion as warmer waters are the preferred environment of the Asian clam.

Identifying Asian Clams

Asian clam. Photo credit: Noel Burkhead - USGS

A bivalve that can grow as large as 5 cm wide and live up to 7 years, Asian clams can be identified by the presence of concentric rings on their shell.  They occur in yellow and brown color morphs and the outer side of the shell can flake, revealing white spots.  Though most mollusk species reproduce by broadcasting their gametes into the water, fertilization occurs in the inner gills of the Asian clam and offspring are not released until they are juveniles approximately 1 mm in size.  Thus, Asian clam invasion can spread through the dumping of water from colonized sources as juveniles are still tiny but also have a high likelihood of survivorship and establishment due to the fact that they are more mature when they are released.  Asian clams are often found at the bottoms of streams, rivers, ponds, and lakes, as well as man-made canals with sandy or muddy substrates.

Ecological and economic impacts

Asian clams are hermaphrodites, and reproduction by self-fertilization can occur, so just one individual could be all that is required to establish a new population in an uninvaded stream.

Asian clam excretions encourage algal growth which reduces water quality for native flora and fauna. Asian clams can aggressively colonize the bottom of waterways and can outcompete native species for space.  Like another notorious bivalve invader, the zebra mussel, Asian clams can colonize and clog canals and pipes which results in monetary costs for mitigation.

A direct impact on population sizes may be possible through harvest and consumption, so check back on Wednesday for a tasty way to enjoy Asian clams!

Edible Invasive species this week: Asian Carp spreading, walleyes, rusty crayfish, sheep lend their rumens, Asiatic Clam, lionfish derby, and pining for a copy of May 2011 Men’s Journal.

Sunday, April 17

Freshwater Fishing: Early success comes mostly in netting of invasive species

Monday, April 18

Rustilicious: A Primer on Catching & Eating Great Lakes Lobster

Sheep chow down at Univ.; Method helps control plants

Tuesday, April 19

Fishing tournament targets invasive lionfish

Wednesday, April 20

Take an Invasive Species to Dinner

10 invasive species for eating

• Brought to our attention by Stephen in the comments via homeschoolcooking

Thursday, April 21

Lake George’s Asian clams targeted as nuisance, but could be delicacy

Friday, April 22

Pulling Together Initiative

• funding opportunity!

Accidental environmentalist designs furniture from invasive species

Asian carp found at Wisconsin border

Saturday, April 23

Men’s Journal

• There I was, waiting for a hair cut, when I spotted on article in the May 2011 Men’s Health.  It had some really great ideas, but I couldn’t finish reading it and haven’t  found myself a copy.