Edible Aquaculture

Warm Freshwater

• In aquaculture, warm freshwater is defined as being between 70 and 90 degrees Fahrenheit. In the U.S., this warm temperature can be achieved seasonally in outdoor ponds. Tanks or indoor facilities allow farmers to better control the water temperature for ideal conditions year round. The most common types of edible aquaculture that are suited to warm freshwater are different species of fish including catfish, crawfish, tilapia and striped bass. Catfish are seen as the most important in terms of acreage, investment and the value of the final product. Crawfish, also called crayfish, is the most widely raised crustacean in the U.S. Worldwide, tilapia tops the list as the most widely raised warm freshwater fish. It is growing in popularity in the U.S. Though striped bass has long been a popular sport fish, it is becoming more common as a food fish, sold in restaurants and supermarkets.

Cool freshwater

• Cool freshwater is defined as water below 70 degrees Fahrenheit. Cool freshwater growing operations in the U.S. are generally located in northern states or in mountainous parts of the south. Some of the first commercially raised fish in the U.S. were cool water species. By far the most common cool freshwater fish commercially raised is trout. Several varieties can be found at fish farms. Though some are raised directly for food purposes, many are raised to be released into streams and lakes. Walleye is another common cool freshwater fish that is raised for sporting purposes. In the U.S. the only cool freshwater fish that are presently raised exclusively for food are the green and lake species of sturgeon.

Saltwater and Brackish Water

• Aquaculture that uses saltwater or brackish water is known as mariculture. Unlike many freshwater growing operations, these farms rely on either natural marine water such as oceans or gulfs, or natural estuarine water such as bays, inlets and mouths of rivers. With so many saltwater fish imported by the U.S. on an annual basis and with the continued decline in the populations of saltwater species, there is tremendous economic potential in saltwater and brackish water aquaculture. However, this form of aquaculture is not without environmental costs. The practice of farming fish in open net farms generates large amounts of waste that contaminate the surrounding water. The most common types of seafood raised in saltwater and brackish water environments are shrimp, salmon and mollusks of which the oyster is the most important. Other saltwater or brackish water seafood crops include clams, lobsters, crabs, milkfish, Atlantic croakers, red drums, pompanos, striped mullets and red abalones.

Plant and Algae

• In the U.S., plant aquaculture makes up a very small percentage of present aquaculture operations. The edible plants grown in aquaculture include brown, red and green algae; watercress and Chinese water chestnuts. In addition, water spinach and duckweed are grown for animal feed. While the different varieties of algae are grown in saltwater, all the other aquatic plants are grown in freshwater.