Intensive Fish Farming

One of the fastest growing food demands our planet faces is for fish. Available at nearly every restaurant, fish are a staple item in many peoples' diet. Though the oceans are full of life, and much of it is harvested, aquaculture or fish farming is an industry that supplies much of the world's fish stock.

  1. Basics

    • Intensive fish farming, as opposed to extensive farming, is a system in which fish production can be willingly increased. The requirement is an increase in water oxygenation, feeding and fresh water in accordance with the amount of fish desired. This, naturally, calls for enormous water purification systems (think of them as giant, complex filters akin to the smaller ones found on home aquariums) that must be expertly integrated into the farm.

    Difference

    • The primary difference between intensive and extensive fish farming is the food supply. In extensive fish farming systems, the fish are fed through photosynthetic means. Through fertilizing the water, fish feed off of primarily phytoplankton, which limits the fish supply. In intensive fish farming, however, fish are fed with an outside source, which produces a much higher yield that can be altered in correspondence with demand.

    Cost

    • Intensive fish farming, generally, is a much more costly operation than extensive fish farming. Much of this has to do with the higher cost of food. Many fish are carnivorous and, therefore, with intensive fish farming, a high amount of protein is used. This contrasts to extensive farming, where much of the food (phytoplankton and algae) is provided through a natural means.

    Aeration

    • A large amount of fish means a large amount of oxygen is needed. This is attained through aeration of the water. There are several ways this is achieved. One method is through bubbling, where air pumps are forced through a porous stone in the water. The air bubbles through the stone, thus oxygenating the water. In a cascade system, a series of waterfalls keeps the flow of water constant. Oxygen can also be added via aqueous means, whereas it is pumped directly into the water. Some fish, like catfish, are far more tolerant of a lower-oxygen environment and are therefore more suitable for intensive farming.

    Disease

    • Because of the higher volumes of fish in more confined areas, the risk of spreading pathogens is high, unless extensive monitoring is carried out. It is important that water quality is kept to a maximum.

    Recent Developments

    • Until recently, attempts at intensive farming of ornamental fish have been futile. However, due in part to the high value of fish like koi, closed-system breeding has grown in various countries. In the United Kingdom, Germany and Israel, several intensive fish farming facilities for ornamental fish have developed.