Approximately l7 species of edible mussels are harvested or cultured worldwide. The blue mussels, Mytilus edulis and M. galloprovincialis, are the most common species.

China leads the world in total tonnage of mussels harvested, with Spain second, the United States l2th, and Canada ranking l9th.

France began its mussel cultivation by accident 700 years ago when a shipwrecked Irish sailor Patrick Walton strung a net between two poles in the ocean to catch seabirds for dinner.

He found that the mussels growing on the poles made a hearty meal, and so the "bouchot" industry was born. There are now over 700 miles of mussel poles stitching the coast of France.

These oak poles are placed in long rows three feet apart in areas where they and their delectable mussels are exposed at low tide. The mussels can be thinned and harvested easily, but grow more slowly because they are not submerged and feeding 'round the clock. Basically family operations, these farms have the lowest meat yield per acre, but France's long expanses of intertidal mud flats make this type of cultivation ideal.

In Spain, culture on hanging ropes began in l90l at Tarragona on the Mediterranean coast. In the late l940's the Galacian region, which now comprises the bulk of Spanish mussel production, entered into cultivation of M. edulis and M. galloprovincialis.

Spain produced more than 200,000 metric tons of M. galloprovincialis in l990. Three-quarters were consumed by Spaniards. Upward of 3500 mussel operations, many family-run, grow the mussels on huge rafts from which ropes are suspended. This vertical use of the water column results in the highest yield of any mussel operation in the world, up to 300,000 pounds of meat per acre.

Even though you will find mussels in the market year-round, don't buy them during their spawning season, when their meat is mushy and their shelf life reduced.

The ones you see most frequently are Atlantic blue mussels. For them, spawning takes place in summer, so the best seasons are all winter, and early spring.

Mediterranean mussels are grown in the Puget sound. The Mediterranean spawns in winter, so its peak seasons are spring, summer and fall.

Large, green-lipped New Zealand mussels, known as greenshell mussel, are usually only available frozen, so season is not an issue.

Mussels are usually graded by size, ranging from two to four inches. Mussels can be wild or cultivated.

Mussels grow in coastal waters all around the world. In the wild, they are attached in clusters by a tough thread to rocks, gravel, or any underwater surface they can find. Wild mussels rarely appear in market. They are easily recognizable by their thick rough shells. Most wild mussels contain sand, and the meats are smaller than those of cultivated mussels.

When you buy mussels in the market labeled cultivated, it can mean one of several things.

The price usually gives a clue to how they were raised. The most expensive and best-quality mussels are called "off-bottom" mussels, which are grown on ropes or posts planted vertically in mussel farms.

• When it comes to Omega-3, the miracle fatty acid found in fish, mussels have more of it than any other shellfish.
  
• One pound of mussels, in the shell, yields three and one-half ounces of raw mussel meat or l00 grams that is the equivalent of 95 calories, 14 g. of protein, 2.1 g. of fat, .5 g saturated fat, 55 mg. cholesterol, and sodium 284 mg.
  
• They filter water (up to 20 gallons a day!)
  
• There are a wide variety of mussels to both fresh and saltwater.
  
• Easy to feed, Mussels can find 20 million edible tidbits to graze on in just a liter of seawater.
  
• They can walk. Mussels have an appendage called a foot that enables them crawl.
  
• Mussels can live up to 50 years!
  
• The mantles of lady mussels are orange, gents are creamy white.
  
• During spawning, mussels can lose up to a third of their body weight. It is not recommended to buy mussels during spawning season, when their meat is mushy and their shelf life reduced.
  

Quality mussels are easy to recognize. Fresh mussels smell clean, like the ocean, and the shells of live mussels are tightly closed. If the mussel is slightly open (no more than 1/4-inch or 0.635cm), tap the shell, and a healthy mussel will close it within 30 seconds.

Refrigerate mussels in a bowl, and cover with a damp towel. Never store mussels in water or in an airtight container-either method will kill them. Mussels should be cooked as soon as possible, but keep for up to a week.

To freeze, remove mussel meat from shells and wrap in freezer paper or plastic, then over-wrap with a plastic bag. Store for up to two months.

To thaw, place mussels in refrigerator overnight. To thaw more quickly, wrap mussels in waterproof plastic and place in a sink with cool running water, allowing about 30 minutes per pound (about 454g). For fastest thawing, use the defrost cycle of your microwave allowing 3 to 5 minutes per 1/2 pound (227g). Let stand for 3 minutes.

Inspect mussels to make sure they are tightly closed. Just before cooking, clean wild mussels by scrubbing with a stiff brush and pulling off the beard with a quick tug. Cultivated mussels need only be rinsed in cold water. To remove meat, either steam open or pry shells open and pick out meat.

Place 1/4-inch (0.635cm) water (wine and seasoning optional) in the bottom of a large pan, and add mussels. Bring water to a boil, reduce heat, and simmer until shells open (four to five minutes). Throw away mussels that don't open. Serve mussels in bowls with broth.

Heat frying pan, then add butter or oil. Add mussel meat and sauté until brown, about two to three minutes.

http://www.greenshell.com/Recipes.asp

Sources of above information:
http://www.gnc.com/health_notes/Food_Guide/Mussels.htm
http://www.chefdecuisine.com/seafood/mussels/musselspostcards.htm