Fighting seafood stocks collapse, helping mussel fisheries and getting rid of an invasive species : can we make good use of a nuisance?

Seafood, many of us love it, and we eat so much of it that the sustainability of including it in our diets is debatable. This is often because we are limited in what we currently eat, or know how to eat, which means many stocks of our favourite fishy foods are being depleted, and many are borderline to collapse with management strategies struggling to cope. 
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As I have already mentioned, eating seafood such as mussels can be sustainable and healthy. As I also mentioned, my current research investigates how to improve mussels cultivation on the seabed. One of the biggest problems and causes of mussel loss is predation on the mussels. Because of the natural way in which they are cultivated, they are subject of many natural pressures - and predation is one of them. Crabs are opportunistic species, and when small mussels are relayed on the seabed they aggregate and feed as much as they can - a little bit like going to an 'all you can eat' restaurant. 

Now, the crabs I am talking about are not the crabs that we are used to see in the fishmarket or the crabs that are currently commonly eaten.  These crabs are called green crabs, shore crabs or, in latin, Carcinus maenas and they happen to also be an invasive and nuisance species in the coasts of the US where they are greatly damaging habitats and decreasing biodiversity. 

So - could we learn how to cook them and make good use of a nuisance species?

In Italy, for example, we eat a closely related species, Carcinus aestuarii, along the Adriatic. Fishermen harvest the crabs just before they molt, and these softshelled crabs, called Moeche, are placed in an egg mixture, then fried and eaten mostly as aperitivo - YUM! 
On a really interesting website, called eattheinvaders,org (also amazing for recipes of other nuisance species, including herbs) there is

a recipe for soft shelled crabs:

2 soft-shell crabs per person
about 2 teaspoons of butter per crab, or enough to cover the bottom of the pan
Cleaning a softshell is easy, for in this condition it is far from being its usual belligerent self and can be handled with impunity. With a sharp knife remove the eyes and the stomach, which is the soft substance just below and behind the eyes. Make a slit along each side, fold back the top skin a bit, and remove the “devil’s fingers”—or gills—those spongy strips just under the back. Rinse the crab in cold water and the job is done.
Melt butter over medium heat in a pan equipped with a tight cover. Put in the crabs, cover, and sauté for about 10 minutes, shaking or turning them occasionally so they brown to an even golden color all over.
Soft-Shells should be served with French bread. Garnish the crab with lemon slices, parsley, and watercress.

And for the Moeche

As many soft-shell crabs as you can find
3 egg yolks
1 cup flour
3 tablespoons of grated Parmesan cheese
salt to taste
Wash the moleche, or softshell crabs, in salt water. Beat the egg yolks and place in a bowl with a pinch of salt and Parmesan cheese. Mix the crabs with egg, allowing them to rest in the bowl for a few minutes to absorb the yolk.
Dip the crabs in flour and fry in hot oil (375 degrees for approximately five minutes or until golden brown). Dry them on paper towels to absorb the grease. Sprinkle with salt and serve hot.


From the same website, a comment from Mark Zanger says "I’ve hit only some big ones on the bay shore of lower Cape Cod,  but find them so delicious they are worth picking from the shell. [...], I will stir-fry them black-bean sauce in the Cantonese manner.",  and apparently chefs have been challenging themselves to try new recipes. Rich Vellante, executive chef of Legal Sea Foods in Boston, told the Boston Globe that green crab stock had a “pleasing ocean flavor.” He thought he could do something with it–and has started testing risotto and minestrone dishes. 

So I am calling all "wanna-be-chefs" to try out new recipes with these nuisance, I for one will challenge myself to try out some new recipes and why not, maybe host a crab party (NIOZ people you are warned in advance now, put your cooking hats on!) 

Moreover, eating these crabs cannot only be useful in terms of getting rid of an invader (where it is one) and reducing mussel losses, but could also create a new fishery - contributing to mussel farmers  and other fishermen salary. I believe that if fished mindfully in the areas where it isn't an invader it could provide benefits to local fishing communities. So let's get cooking and spreading our recipes :)

And keep your eyes open for some of my own trials on the recipe page (when I actually find some time to do so) and if you want more info on my work feel free to contact me :)

Some interesting articles of crabs effect on mussel plots in the meantime (will add one of my own once it gets finally accepted....):

Capelle, J. J., Scheiberlich, G., Wijsman, J. W., & Smaal, A. C. (2016). The role of shore crabs and mussel density in mussel losses at a commercial intertidal mussel plot after seeding. Aquaculture International, 24(5), 1459-1472.

Calderwood, J., O'connor, N. E., & Roberts, D. (2015). Effects of baited crab pots on cultivated mussel (Mytilus edulis) survival rates. ICES Journal of Marine Science, 72(6), 1802-1810.