), and the soil from those former farms remain hypersaline, acid and eroded [22]. Therefore, selleck Pazopanib those soils cannot be used for agricultural purposes and are unusable for long periods. In addition, the application of lime and other chemicals used in aquaculture to treat the soil can also modify its physicochemical characteristics, which could aggravate the problem [23].(3) Pollution of Water for Human Consumption ��Although few studies have been conducted in relation with such topic, there are some signs indicating that inland aquaculture has been responsible for the deterioration of water bodies used for human consumption [21]. For instance, preliminary calculations revealed that an intensive aquaculture system farming three tons of freshwater fish can be compared, in respect to waste generation, to a community of around 240 inhabitants [24].

Although most of the aquaculture farms produce marine species, there is a growing sector of aquaculture farms producing freshwater species, which is a point of concern considering the above information.(4) Eutrophication and Nitrification of Effluent Receiving Ecosystems ��The eutrophication or organic enrichment of water column is mainly produced by nonconsumed feed (especially due to overfeeding), lixiviation of aquaculture feedstuffs [25, 26], decomposition of died organisms, and overfertilization [27�C30].

It is well documented that from the total nitrogen supplemented to the cultured organisms, only 20 to 50% is retained as biomass by the farmed organisms, while the rest is incorporated into the water column or sediment [31, 32], and eventually discharged in the effluents toward the receiving ecosystems, causing diverse impacts such as phytoplankton blooms (sometimes of toxic microalgaes, such as red tides) [33], burring, and death of benthic organisms, as well as undesirable odors and the presence of pathogens in the discharge sites [34]. The impact may be more or less severe depending on some factors such as the intensification of the system (density of organisms), which is directly related to the amount of feed supplied [26, 35]. The feed conversion ratio (FCR) is a well indicator of the effectiveness of feeding and, consequently, of the retention of nitrogen and carbon as biomass of the Dacomitinib farmed organisms. For instance, farms culturing the tiger shrimp Penaeus monodon usually report FCRs ranging from 1 to more than 2.5; such huge difference is later reflected in the amount of organic matter, nitrogen, and phosphorous discharged in the effluents, which may range from 500 to 1625kg, 26 to 117kg, and 13 to 38kg, respectively, for each ton of shrimp harvested [28]. The estimated mean FCR worldwide for shrimp aquaculture is 1.