Fish Farming
Fish farms or fish farming is a form of aquaculture. The act of fish farming is about raising fish commercially in tanks or enclosures for human consumption. There are different types of fish farms that utilize different aquiculture methods.
Fish are an important source of animal protein for billions of people. However, the supply of fish caught in the wild–particularly from the oceans–has already receded from its peak, and future supply is under threat. As the wild fish harvest has stagnated, aquaculture has grown to meet the world’s growing demand for fish.
Fish, including finfish, crustaceans, and mollusks, contributed 16 percent of global animal-based protein for human consumption in 2009, and are the primary source of animal protein for nearly 1.3 billion people. Fish also contain important micronutrients―such as vitamin A, iron, and zinc―and omega-3 fatty acids that are essential for maternal health and early childhood development, but that are often deficient in developing country diets. People consumed 128 Mt of both wild-caught and farmed fish in 2010, an all-time high, and demand is projected to grow over the coming decades.
In many developing countries, fishing is often a livelihood of last resort in coastal communities; restrictions can lead to severe hardship and governments are reluctant to impose them.
At an average annual growth rate of 6.2 percent per year between 2005 and 2010, aquaculture is the world’s fastest growing animal food producing sector.
Aquaculture is diverse, producing more than 300 fish species through a wide variety of production systems in 2010. But just six species groups—carps, mollusks, shrimps, tilapias, catfish, and salmonids— account for 87 percent of production.
Much of the early environmental debate about aquaculture focused on whether it truly served as a net source of fish because carnivorous405 species such as salmon, shrimp, and many other marine fish consume more wild-caught fish in the form of fishmeal Creating a Sustainable Food Future: Interim Findings 99 and fish oil than they produce as food. This concern may have been overstated, as most aquaculture production consists of omnivores, herbivores, and filter feeders that consume little to no fish-based ingredients.
The area under aquaculture ponds is small compared to total cropland, but this level of expansion would be significant environmentally in absolute terms. As the indirect land demands for feed are comparable between aquaculture and poultry, such increases in direct land use would also make aquaculture in ponds less efficient as a source of animal calories and protein than poultry. At least as importantly, little new land is available for aquaculture or any agricultural expansion in Asia, where most aquaculture exists. A key challenge, therefore, will be for aquaculture to more than double production by 2050 with no or minimal land expansion—and preferably to limit any needed expansion to economically and environmentally low-value areas.
Yet an issue still remains: Can aquaculture more than double production by 2050 without exceeding the global limits of fishmeal and fish oil supply? The catch of small fish from “industrial” fisheries used for fishmeal is on the decline, dropping by half from 30 Mt in 1994 to 15 Mt in 2010.