What subsea dweller has a foot but does not use it to move; has no arms yet holds onto its host with tremendous adhesion; is considered a protective barrier for jetties and bridge structures; is ground up for fertilizer; and is savored by seafood lovers? It is often overlooked by divers as a drab clump of shells overgrown with algae and surrounded by sea anemones, yet a close-up view yields a beautiful pearly lustered inner shell with a cylindrical siphon that filters microscopic morsels of food from the passing water. This tiny bivalve is commonly known as the mussel. Scientifically, it belongs to the order Mytiloida and the family Mytilidae. Along the northeast coast of the United States, the edible species of mussel is the blue mussel, Mytilus edulis. It is found in clusters along rocky jetties, clinging to underwater portions of bridges, boat bottoms or almost any underwater debris. Mussels have been found attached to lobster shells, crab shells and pieces of driftwood.
Unlike most shell-type animals, the mussel has developed a unique method of locomotion. The foot itself is a weak and flabby string of muscle, but at its base there is a gland that, when compressed, ejects a gelatinous substance that hardens and forms threads, called byssal threads, that have enough holding power to support the weight of the bivalve. These adhesive threads allow the mussel to remain steadfastly in place during the most horrendous conditions. To move, the mussel simply ejects new threads farther out in the direction that it wishes to travel, releases the old threads and hangs this process, the mussel continues its journey. This certainly is not the most speedy means of travel but it serves the bivalve admirably. With this lightning fast means of locomotion, it is no wonder the mussel spends its entire life in a very confined area.
The mussel provides a service to man that is quite often overlooked. Colonies of this animal grow rather quickly around bridge abutments and along jetties, with new mussels growing on top of older ones. This creates a thick mass of shellfish whose bulk offers the structure protection from damage caused by erosion. Gaps among mussels quickly fill in with sandy silt, further increasing the bulk of this natural buffer.
One of the main reasons for the rapid expansion of mussel beds is the bivalves’ amazing reproductive capabilities. At breeding time, the mussel’s mantle becomes a brooding chamber, allowing the extremely large (larger than any other mollusk) reproductive organ to produce enough tiny yellow eggs to fill the space between the shells. When the eggs hatch, the tiny fry settle on almost any object to keep from suffocating in the soft mud of the sea bottom.
There are very few seafood delights that are a sure fire catch for the scuba diver. Lobsters can be very scarce and difficult to catch; spearfishing can be a very frustrating experience, leaving the diver with an empty game bag; scallops are not always easy to find; but mussels, those lovely, tasty delicacies, are always there, waiting for the collector.
Now that you’ve found them, how do you know which ones to take? Don’t be turned off by the drab looking growth on the outside of the shell, choose the size that appeals to you and pick away. But first, remember that mussels close to sand are most likely to have a sandy taste. Because it is a filter feeder, the mollusk will draw sand into its siphon if it is suspended in the water column. So, climb higher on the wreck or the rock pile, where the sands don’t reach, and pry the mussel from its foothold. Load them into your goodie bag and head for the surface. Remember, these delicacies will add weight! Proceed cautiously.
Two important cautions exist with mussels. One, if you gather the shellfish from jetties or bridge abutments, do not take those that are out of the water during tidal changes. Two, do not collect the bivalves from polluted areas and immediately after “red tides.” The animal tends to absorb toxins from both of the aforementioned conditions. After the red tide has subsided, the mussel will cleanse itself rather quickly and be suitable for consumption. In some areas of the country, mussels are quarantined during certain months. Check with local fish and game departments before you go collecting.
Once on board, care of mussels is rather easy. Tie a line to your game bag and hang it off the side of the boat so the bivalves are submerged in water. Now, the real secret to cleaning mussels: As the boat starts its trip back to the dock, tie the game bag onto a 10-15 foot long, sturdy line and tow it behind the boat. The line should be tied around the bag below the handle and not to the handle itself. The attachment of the handle to the bag is the weak point of the system and the area where the bag will tear first. The flow of water through the bag will tumble the mussels and remove the majority of the growth from the shell exteriors. A word of caution: If the boat is traveling at high speed or if the bag is overloaded, the game bag will not stand up to the drag of the water and may tear open.
Once back at the dock, the mussels must be gotten home so that they can be prepared for dinner. Transporting them covered with wet rags in a bucket, or packing them on ice would be a suitable means of transport. Do not allow the mussels to sink into melting ice water as the shock of sudden immersion in fresh water may kill them. Transporting them in a bucket of seawater can also lead to trouble. The bivalves will quickly use up all the oxygen in the water causing them to expire. Bacteria multiply quickly in a dead mussel, so they must be discarded.
Now all that remains is to cook the mussel to savor the delight of a catch fresh from the sea. Most people are amazed at the difference between a freshly caught mussel dinner and one purchased in a seafood restaurant.