Mussels are a widely appreciated seafood found across the globe. These organisms belong to the group of bivalve mollusks, aquatic invertebrates encased within two hinged shells. Mussels thrive in diverse aquatic environments, from coastal marine to freshwater, and are a popular food source worldwide.
Mussel Biology
Mussels possess a unique biological structure for survival and feeding. Their soft body is enclosed within two symmetrical, hard shells for protection. Mussels are filter feeders, drawing in water through a siphon and straining out food particles like phytoplankton using their gills. This feeding mechanism contributes to water quality by removing suspended particles.
A distinctive feature of mussels is their byssal threads, often called a “beard.” These strong, proteinaceous filaments are secreted by a gland in the mussel’s foot, allowing them to firmly attach to hard surfaces like rocks, pier pilings, or other mussels. Adults are generally sessile, remaining in one place, but can sometimes detach and reattach to reposition. Mussels commonly inhabit intertidal zones, where they are exposed to air during low tide, and subtidal areas.
Popular Edible Mussels
Several mussel species are widely consumed, with distinct characteristics. The blue mussel (Mytilus edulis), also called the common mussel, is a medium-sized marine bivalve found in temperate waters globally. Its shell ranges from black to blue-black or brown, often with concentric growth lines, growing up to 8 inches, though typically 2 to 4 inches at maturity. Blue mussels are recognized for their teardrop shape and smooth shells.
The green-lipped mussel (Perna canaliculus) is indigenous to New Zealand. Identifiable by their smooth, dark brown to bright green shells with a characteristic lime-green edge, they can grow quite large, sometimes exceeding 20 centimeters. Mediterranean mussels (Mytilus galloprovincialis) are commonly consumed and found in the Mediterranean and eastern Atlantic, though they are invasive in many other regions. Their shells are typically blue-violet or black, sometimes shading to light brown, reaching lengths of up to 140 mm.
From Ocean to Plate
Mussels reach consumers through wild harvesting and aquaculture (mussel farming). Wild harvesting involves collecting mussels by hand from natural beds along coastlines, often during low tide. Harvesters pull mussels from rocks or other substrates, taking care not to damage beds. This method is labor-intensive and subject to natural population availability and environmental conditions, including red tide concerns.
Mussel aquaculture is a significant source, offering a controlled and sustainable approach. Common farming methods include rope culture, where mussels grow on ropes suspended from floating longlines or rafts. Bottom culture involves sowing mussel seed directly onto underwater plots. Bouchot culture, primarily used in France, utilizes poles driven into muddy shorelines with seeded ropes wrapped around them. Mussel farming often provides environmental benefits by improving water quality as the mussels filter excess nutrients.
Nutritional Profile and Culinary Uses
Mussels offer a robust nutritional profile. They are a rich source of lean protein, ranging from 12.6 to 24 grams per 100 grams, depending on the variety. Mussels also provide a significant amount of omega-3 fatty acids, including EPA and DHA, beneficial for heart health. A 100-gram serving can contain around 500 milligrams of EPA + DHA.
Beyond protein and omega-3s, mussels are packed with essential vitamins and minerals. They are an exceptional source of Vitamin B12, often providing several hundred percent of the daily recommended value. Mussels also supply significant amounts of iron, selenium, manganese, other B vitamins, zinc, and phosphorus. Their low calorie count, around 100-170 calories per 100 grams, further enhances their appeal. Mussels are versatile and commonly prepared by steaming, sautéing, or grilling for cuisines worldwide.
Selecting and Storing Mussels Safely
Selecting fresh mussels is important for flavor and safety. When purchasing, look for mussels with tightly closed shells. If a shell is slightly open, tap it gently; a fresh mussel will close. Mussels should have a fresh, mild, oceanic scent, not a strong or “fishy” odor, which indicates spoilage. Avoid mussels with broken or cracked shells.
Proper storage helps maintain quality and prevent spoilage. Mussels are live organisms requiring air; never store them in sealed plastic bags or submerged in fresh water, as this will cause death. Instead, store them in an open container, like a bowl or mesh bag, covered with a damp cloth in the coldest part of the refrigerator (1°C to 4°C). If storing on ice, ensure melted water drains to prevent mussels from sitting in fresh water. Mussels are best consumed within three to four days.
Before cooking, clean them by scrubbing off debris and removing byssal threads. During cooking, mussels should open; discard any that remain closed.