The Catch Of The Day - Aquaculture
Knute Hogan, The Culinarian, November 2007

Aquaculture dates back several thousand years to China, Hawaii, Japan and ancient Rome. The practice grew significantly to more widely offer fish as an important source of protein during the Middle Ages. As transportation methods expanded, so did the ability to deliver fresh seafood to inland areas, which in turn, caused a decline in the practice of aquaculture.

Aquaculture was first established in North America in 1889, in Newfoundland, Canada in the form of a fish hatchery, which is a facility that releases juvenile fish into the wild for recreational, or to supplement a species’ natural numbers. Soon after, during the First World War, the practice of managing kelp was developed in California as a resource. The practice of managing kelp came to be defined as macroalgae and is now considered a form of aquaculture called algaculture.

The business of aquaculture, however, has essentially been a product of the last half of the 20th century. Nearly one hundred species have now been domesticated. With the world’s wild fisheries under pressure by an ever growing population in search of fresh seafood, the need for aquaculture has accelerated. A recent study revealed that over thirty percent of the worldwide seafood production is now coming from aquaculture. Increased production is expected in the future. Aquaculture efforts in the United States are primarily focused on creating domestic seafood supply to meet the increasing demand for seafood products. Fish farming is the principal form of aquaculture, while other methods may fall under what is termed mariculture.

Mariculture is a specialized branch of aquaculture, involving raising fish commercially in tanks or fishing enclosures be it in the open ocean, an enclosed section of the ocean, or inland tanks, ponds or raceways filled with sea water. Non-food products produced by mariculture include: fish meal, jewelry and cosmetics. Fish species raised by fish farms include: catfish, tilapia, shrimp, salmon, trout and others.

Recirculating aquaculture systems are an environmentally sound method that utilize water at an optimal level by filtering and cleaning the water to run through the system several times, and adding more water as it evaporates or as it is used to flush away waste material. This method is best suited to indoor fish farms times. Other benefits of indoor fish farms are the small amounts of land required and the opportunity to optimize production by controlled temperature. With a temperature controlled system, there is little influence exerted by the region’s climate.

Movement toward an integrated multi-trophic aquaculture (IMTA) system is deemed optimal. IMTA combines several species in the same system to better achieve a more balanced environment. This approach offers multiple uses of products and, by employing improved management practices, is considered more sustainable and socially acceptable. IMTA can reduce risk with product diversification. By definition, trophic refers to nutrition; trophic level on the food chain. This system separates itself from aquatic polyculture methods that would comingle different fish of the same trophic level.

This evolution of aquaculture envisions parity among the biological and chemical processes through selection of adapted and proportioned species, affording varied ecosystem activity. The resulting benefit is a healthy sustainable environment where several products have a commercial value.

Other forms or variations of IMTA include integrated agriculture-aquaculture systems (IAA). IAA usually make use of a pond and take up small portions of a farm when compared to its other cash crops. IAA can be very productive and is a viable way to introduce further diversity to the farm. Integrated periurban aquaculture systems (IPUAS) are located in or near cities and may or may not employ the use of area waste water in its operation. Aquatic plants are often the focus of IPUAS systems. Another variation of IMTA is the integrated fisheries-aquaculture systems (IFAS) which utilize stock from wild fisheries to establish and maintain their market supply.

Imported seafood (nearly half of which is from aquaculture), accounts for the majority of the seafood that is consumed in the United States. Continued development of US coastal and inland aquaculture is needed, and will benefit regional economies, and serve to increase local sources of a vital food supply. Offshore aquaculture will certainly develop into an important form of aquaculture. Currently, fresh water aquaculture is considerably greater than marine aquaculture in the US.

The National Oceanic and Atmospheric Administration’s aquaculture efforts are focused on creating domestic seafood supply to meet the rising demand for seafood, all within the context of marine stewardship responsibilities. The program currently addresses the aspects of coastal and onshore marine shellfish and finfish culture, including hatchery activities that support important commercial and recreational fishing and some endangered species recovery.

Direct attention to environmental impacts of aquaculture cannot be overlooked. Little is accomplished when short sighted plans are adopted, or when thoughtful consideration to current scientific and industry information is side stepped. The future of aquaculture will require positive participation from growers, management agencies, and consumers to direct this essential sector of the food industry, given the opportunity it will most likely succeed.