Rich and creamy clam chowder served in a sourdough bowl is as much a San Francisco tradition as cable cars and foggy mornings. Clams are available year round at the Ferry Plaza Farmers Market, generally farmed in Tomales Bay. Clam farming is an extremely sustainable enterprise, as clams feed on microscopic plants and particles of organic matter found in the water, naturally filtering it and removing excess nitrogen in the process. Amateur clam enthusiasts can grab a spade and dig for wild clams in the mudflats of Bodega Bay or Marin?s Dillon Beach.

Preparations for clams range from the easy (steamed in white wine and served with melted butter or tossed into pasta) to the more the complex (paella and bouillabaisse). No matter how you prepare them, clams are rich in protein, iron, and B12, and low in contaminants such as mercury.

Steelhead trout, aka rainbow trout, is very similar in color, taste, and texture to salmon. However, most of the trout available in U.S. markets is farm raised, which makes it a more sustainable and cheaper option. Though wild steelhead trout populations have declined due to human and natural causes, management of the U.S. trout aquaculture industry is deemed effective and well regulated. Trout has a robust flavor and can be used in any recipe that calls for salmon.

Shrimp are classified as crustaceans, making them closely related to crab and lobster, though they don?t bear many similarities in looks, taste, or anatomy. Shrimp has long muscular tails, slender, virtually meatless legs, and a much thinner shell. In contrast, the legs of crab and lobster are strong and made for walking, providing a substantial amount of meat for consumption.

Shrimp is one of the most commonly eaten seafood in the U.S., so it is subject to stringent regulations. U.S. shrimp trawlers must adhere to stricter environmental standards than those in most other countries. U.S. shrimp trawlers are required by law to use bycatch reduction devices (BRDs) to limit the amount of unwanted catch. This makes U.S. wild-caught shrimp a ?good alternative,? according to Seafood Watch, while imported wild shrimp is on Seafood Watch?s ?avoid? list. Imported shrimp may also come from farmed sources and should also be avoided due to the varying and often unknown environmental impact.

While shrimp are commonly available frozen, fresh shrimp have a delicious taste that diminishes in the freezing process. The head, shell, and tail are usually removed before eating, and can make a good foundation for a rich seafood stock. To devein shrimp for a cleaner flavor, cut a line down the back with a small knife and pull the vein out.

Shrimp has a light, sea-brine taste and firm, resilient texture. They are good in Italian pasta or Asian noodle dishes (like fettuccine alfredo or pad thai) or fried and served with cocktail sauce.

Scallops have two edible parts: the scallop, aka the adductor muscle (the familiar white and meaty portion most commonly consumed), and the roe (the coral-colored egg sac). The roe deteriorates more quickly and, due to lack of demand, is often removed from the scallop before it is sold?a missed opportunity for American consumers. Roe is a well-known delicacy in Europe, enjoyed for its creamy texture. If you find scallops sold with the roe still attached, be sure to try it. Both the scallop and roe can be served grilled or seared.

Scallops are harvested in two ways: ?off-bottom,? meaning divers handpick them from the sea floor, or ?on-bottom,? using nets called dredges, which are dragged across the ocean floor. The majority of scallops consumed in the U.S. are wild-caught from the Atlantic coast or Canadian fisheries using the dredge method. Dredging can cause disruption to the ecosystems of the sea floor, so scallops harvested by hand are the most sustainable option. The population is abundant and efforts are being made to reduce bycatch, so Atlantic sea scallops are still considered a ?good alternative? by Seafood Watch. Imported scallops are generally farmed and harvested using the off-bottom method.

Wild salmon is found primarily in Northwest Pacific coast or Alaskan waters. The most sustainably caught sockeye salmon is brought to market through the reefnet method, which directs salmon into nets by stringing fishing gear between two boats. This method allows for the unharmed return of bycatch.

Due to the natural cycle of the salmon spawning season, salmon caught in early summer is considered more sustainable than fish caught later in the season. While Alaskan salmon populations are healthy, salmon populations in California, Oregon, and Washington (such as Chinook, aka King) have historically been overfished, with varying levels of recovery. Recent checks indicate that all populations are healthy enough to be rated a ?good alternative? by the Monterey Bay Aquarium Seafood Watch. Drift gillnet, purse seine, and troll gear are acceptable fishing methods in these areas. Ask your fishmonger for as much information as possible about the method of catch and point of origin.

Salmon has oily flesh and a strong, distinctive taste. Its flesh is firm and holds up to canning, where it may be used in place of canned tuna in sandwiches or casseroles. Fresh salmon steaks are hearty and ideal for grilling with citrus, the acidity of which helps break down the meat.

Sardines hold a significant place in American history and culture. Commercial West Coast sardine fishing began during World War I to meet the demand for portable, nutritious, and battlefield-ready food. Monterey Bay was the site of the most intense production of canned sardines, and the sardine plants and the lives of their workers became the inspiration for John Steinbeck?s novel Cannery Row. In the 1950s, the fishery was largely depleted and abandoned, due not only to overfishing but to fluctuating changes in water temperature that rendered the area too cold for the warm-water-seeking sardines.

In recent years, careful management has led to increased sardine populations, and the West Coast has become a thriving sardine fishery yet again. Sardines from Pacific waters are a ?best choice,? while Atlantic sardines in the Mediterranean should be avoided due to inefficient management and diminishing populations.

Sardines are prepared much like herring, another small, oily fish. They are traditionally featured in Sicilian or Mediterranean dishes, are stuffed and fried, or are served whole, simply grilled, on fresh bread.