Green Crabs Summit - have the crabs won?

Listen to two speakers then a discussion on the monumental invasion and occupation of Maine state coastal waters by Carcinus Maenas, the Green Crab, and find out who won "this round".

Dr Cynthia McKenzie of the Canadian Dept of Fisheries and Oceans, Newfoundland,  and Chad Coffin, head of Maine Clammers Association, spoke in the afternoon session of the December 16, 2013 Maine Green Crab Summit at the University of Maine in Orono. The event was also streamed live on the internet.

* Cynthia McKenzie 30 min 
* Chad Coffin, 36 minutes
* Panel Discussion 17 minutes
* Pat Keliher  13 minutes


Recordings also include a discussion - occasionally very heated - among the panel and the audience,  including those on the internet, followed by closing remarks by Maine DMR Commissioner Pat Keliher.  The most important consensus of the summit was to kill as many green crabs as possible. Efforts are also underway by the Maine Clammers Association to establish gated-off crab-free coves.

 Coffin of the Clammers' Association heaped scorn on "coastal cleanups" as wastes of money and volunteer energy for cosmetic improvements, and suggested  the money and effort be better spent on  habitat and or species restoration.

Coffin also urged that towns with under 20 licensed commercial clammers lose their municipal shellfish commission, saving DMR money to concentrate on those places with viable shellfisheries and saving those towns the expense of an armed shellfish warden. "There's no clams for them to protect? Doffin said.

Little more than a century after introduction into the Gulf of Maine, the swarming green crab has succeeded in wiping out softshelled clams and mussels.

It is outcompeting lobsters for shallow water lobster trap bait and other foods. Is gnawing eelgrass flat and is boring holes in saltmarsh sediments.

Have the green crabs won?

Help requested for Maine green crab survey

Clammers in Casco Bay have reported seeing very few sublegal clams this spring and summer. They are also witnessing what appears to be an explosion in populations of green crabs.  

Maine Clammers Association is trying to extend the observations made in the Freeport area to other areas along the Maine coast to see if a similar reduction in clams and increase in green crab infestations are happening elsewhere.  

If you have seen pockmarking on flats, if you have seen green crabs in channels or on mudflats, if you have seen green crabs causing erosion in shoreland areas, please contact:

Chad Coffin – Maine Clammer’s Association: friendsoftheclammers@comcast.net    or Brian Beal – University of Maine at Machias/Downeast Institute: bbeal@maine.edu

Listen to Chad Coffin testify before the Maine Legislature's Marine Resources Committee earlier this year, on the devastation wrought by green crabs. And to the questions the legislators responded with.

CRABS TERRORIZING MAINE COAST. So long, Maine mussel mats!

The little crab that would rule the Maine coast

Listen below to dramatic testimony before the Marine Resources Committee January 31, 2013 from longtime clammer/shellfish leader Chad Coffin, president of the Maine Clammers Association and a member of Friends of the Clammers.


Maine Clammers Association presentation & Q&A, by Chad Coffin   
Complete presentation and Q&A 36 minutes 36 seconds
Broken into sections:
Part 1  4min 30sec   Part 2 4min 56sec    Part 3 5min 15sec    Part 4 6min 27sec    Part 5 5min 28sec   Part 6 5min 40sec  

Highlights of Coffin's presentation:

We are in big trouble, Chad warned the legislators, The clams and mussels of the lower intertidal shores and the fishes of the shallow subtidal waters of Maine are vanishing. 

200 square miles of mussel beds have vanished from the intertidal Maine coast. These 6" thick mussel mats with up to 16,000 mussels per square foot, were a mainstay of the Eider ducks, which too are vanishing from our environment, along with many other organisms.  

Almost all of this, Chad Coffin told the legislators, is thanks to one small animal -  the European Green Crab, aka Carcinus Maenas. It has been around Maine since the late 19th century, but became  a serious clam predator in the 1950s. 

IN THE LAST TEN YEARS the green crab population has risen exponentially.  According to Coffin, they are eating Maine's intertidal and coastal shallows empty of all other life. The crabs eat the eggs of mummichogs and silversides and other small fish. They eat juvenile lobsters.  They out compete juvenile lobsters 63 out of 65 times for food and shelter. Carcinus Maenas  larvae eat zooplankton that are the food of mussel & clam larvae and adults. Older green crabs eat young mussels and clams themselves. Casco Bay has lost its mussels from its shallows and intertidal zone and a has experie3nced99.9 percent drop in clam spat settlment


At the close of Coffin's testimony, a legislator remarked sourly that Chad will soon have to deal with two more aggressive invaders: chinese mitten crabs and Asian Shore Crabs

What is to be done? Chad's not sure, beyond: see a green crab? Kill it!