Production

Aquaculture production occurs in ponds, raceways, cages, rafts, baskets, lines, recirculating systems, and by ocean and reservoir ranching.[5] The majority of finfish and crustacean production worldwide occurs in earthen ponds,

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

¡Capture Fisheries □ Aquaculture

Fig. 1 Volume of capture fisheries and aquaculture production. (Figure courtesy of Ref. [2].)

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

¡Capture Fisheries □ Aquaculture

Fig. 1 Volume of capture fisheries and aquaculture production. (Figure courtesy of Ref. [2].)

but fish can be raised in open waters by confining them to cages or net pens. Salmon and freshwater paddlefish are ranched by releasing young into the wild for recapture and sale as adults. Very intensive indoor recirculating systems rely on biofilters or hydroponics to remove the dilute nitrogenous waste products of fish. Shellfish are cultured on rafts, in baskets, and on lines.

Species that are good aquaculture candidates: 1) are easy to reproduce in a controlled fashion; 2) accept prepared feeds; 3) are hardy; 4) tolerate a wide range of water quality conditions; and 5) have high market value. Seed for aquaculture production often closely resembles its wild counterpart. Although some carp strains have undergone selective breeding for decades, there has been little genetic improvement of most aquaculture stocks. Recent bioengineering advances have come under intense scrutiny by those opposed to genetic manipulation. Seed production in aquaculture is further complicated by complex life cycles (as many as 20 + larval stages of some crustaceans) and the small-sized larvae of many marine species.

Most forms of aquaculture production rely on artificial feeds. Diet formulations are complex due to the range of dietary habits. Fish such as tilapia and some carp are primarily herbivores, fish such as catfish have omnivorous dietary habits, and salmon are essentially carnivores. There is no parallel in terrestrial agriculture for large-scale production of carnivorous species as food. In spite of the range of natural dietary habits, typical crude protein levels in commercial, pelletized fish diets range from 28 45% protein.

Mechanical aeration is used frequently to maintain acceptable levels of dissolved oxygen. Ammonia removal technologies are required in very intensive systems. Harvesting, holding, and transportation of aquatic animals are complicated by requirements to maintain adequate water quality (Fig. 2).

Management intensity and risk vary with the species produced and the culture system employed. Some crops require only a few months of production, whereas others require several years. Increasing intensification can be accompanied by increasing problems of fish health. Aquaculture industries lag behind other forms of animal agriculture in understanding disease transmission and in development of effective control mechanisms.

Most aquaculture businesses are classified as small businesses. In the United States, 84% of catfish, 93% of baitfish, and 95% of trout farms are small businesses.[7] Some integration has occurred, but the extent of consolidation of aquaculture supply and marketing chains has lagged behind that of other animal production industries. The broiler industry has been widely cited as a model path for aquaculture industry evolution, but the nature of aquatic species, systems, and market channels is more complex. The greater degree of perishability of seafood products and the consequent consumer demand for freshness have slowed consolidation of distribution networks. Salmon, shrimp, and catfish are the commercial large-scale aquaculture businesses most likely to follow the poultry industry integration model.

In the United States, the U.S. Department of Agriculture (USDA) is the lead agency in aquaculture and is supported by the National Oceanic and Atmospheric Association (NOAA). Private associations of producers, such as the Catfish Farmers of America, the U.S. Trout Farmers Association, and the American Tilapia Association, are all affiliated with the umbrella trade group, the National Aquaculture Association. The U.S. Aquaculture Society, a chapter of the World Aquaculture Society, provides professional support for aquaculture. The gateway to aquaculture resources on the web is AquaNic: the Aquaculture Network Information Center (http:// aquanic.org).

Diabetes Sustenance

Diabetes Sustenance

Get All The Support And Guidance You Need To Be A Success At Dealing With Diabetes The Healthy Way. This Book Is One Of The Most Valuable Resources In The World When It Comes To Learning How Nutritional Supplements Can Control Sugar Levels.

Get My Free Ebook


Post a comment