Fire It Up - Andrew Schloss [134]
Chapter 11
Crustaceans & Mollusks
Crab, lobster, shrimp, clams, mussels, oysters, scallops, squid, octopus, and cuttlefish rank among the world’s favorite seafood. They’re so popular that the continual harvest of wild seafood like shrimp has endangered the survival of other marine life for a variety of reasons, including habitat destruction. The aquaculture industry has blossomed in the last century in response to the ever-increasing global demand for shellfish. But not all farmed shellfish gets an eco-friendly OK from seafood watch groups. Both wild and farmed shellfish have their advantages and disadvantages.
Wild vs. Farmed
Managing the vitality of our oceans is complicated. Every country and region has different levels of regulation. Some countries harvest wild shellfish indiscriminately, destroying coral reefs and endangering marine life. Others strictly regulate harvest months and limit total catch to ensure the continued abundance of seafood from our oceans. For instance, in the 1980s, sea scallops fished from North American waters were endangered from overfishing, but careful management has replenished wild stocks and U.S. sea scallops are now considered abundant.
Similar concerns about other shellfish have been a boon to the aquaculture industry. Farmed seafood now accounts for more than 40 percent of the world’s supply. Although it accounts for a small amount of the current U.S. supply of all shrimp, shrimp farmed in the United States come from well-managed aquaculture operations with minimal environmental impacts such as water pollution. Farmed bivalves like clams, mussels, and oysters make a low environmental impact and can even improve water quality since filter feeders help to clean the water.
With all these variables, trying to make wise shellfish choices can be confusing. The United States Department of Agriculture (USDA) has stepped in and now requires that all seafood carry a label stating whether it is wild-caught or farm-raised and identifying its country of origin.
Crustaceans
Crustaceans and mollusks are the two major families of edible shellfish. Crustaceans include crab, lobster, crayfish, and shrimp. They have a hard shell, which they periodically outgrow, a process called molting, during which the animal forms a tough outer cuticle over its body, crawls from its shell, and pumps itself up with water equaling nearly twice its original body weight. The cuticle slowly mineralizes and hardens, forming a new shell with enough room for growth. During molting the flesh of wild crustaceans becomes inedible, except for soft-shell crabs, which are removed from the water as soon as they are about to shed their shells. Crustaceans are also highly perishable, spoiling within hours of death. That’s why they are mostly sold alive or cooked. Most shrimp are frozen at sea, and then thawed for sale at markets. When buying live lobsters and crabs, make sure they are active with a clean, fresh scent and no ammonia odor.
Mollusks–Bivalves, Gastropods, and Cephalopods
Clams, mussels, oysters, and scallops are bivalves enclosed in a pair of calcified shells. The part we eat differs slightly in each bivalve. All bivalves consist of a “foot” to secure them and adductor muscles to open and close their shell.
The foot is the main edible part of clams, as it is for mussels, but mussels attach their feet to rocks or ropes, with the help of fibrous hairs called the beard, which must be removed before cooking. Oysters also attach themselves to rocks, but their edible part is called a mantle instead of a foot.
Scallops neither burrow nor attach themselves to rocks. They rest on the ocean floor, using their adductor muscles to rapidly open and close their fan-shaped shells, which propels