“Green water” microalgae: the leading sector in world aquaculture

Abstract

Freshwater fish culture is generally considered the largest sector in world aquaculture. Several of the leading species consume "green water" plankton. This planktonmostly microalgae (phytoplankton) and also bacteria, protozoa and zooplankton-grows in man-made fertilized water impoundments. The quantity of "green water" microalgae consumed by fish and shrimp is estimated here at a quarter billion ton fresh weight a year, about three and a half times as much as the entire recognized aquaculture. This estimate is based on the quantities of the microalgae consumed and the efficiencies of their use for growth by the main species in aquaculture. The cost of producing "green water" microalgae by the aquaculturists-mostly in SE Asia-is low. The populations in "green water" are biologically managed by the cultured fish themselves. The fish with their different feeding habits help "manage" the composition of the plankton and the overall water quality as they grow. The aquaculturists further manage "green water" through simple means, including water exchange and fertilization. Cost is remunerated partially by the income from sales of the fish and partially by bio mitigation services that "green water" polyculture ponds provide the aquaculturists in treating farm and household waste. A comprehension of the scale and importance of the microalgae sector to world aquaculture should lead to more research to improve understanding of algal population dynamics, growth factors, and efficiency of food chains. The consequent improved control of the plankton's interaction with fish and shrimp production in "green water" will undoubtedly contribute much to the expansion in production of seafood.

Acute and subchronic safety assessment of Porphyridium purpureum biomass in the rat model

“…Use of whole algal biomass as animal feed has been practiced in poultry and aquaculture for many decades (Becker 1994;Neori 2011;Shields and Lupatsch 2012). Algal biomass has been reported to contain balanced amino acid profile and as an alternative to conventional protein sources like soy, corn meal, or skim milk (Fevrier and Seve 1975;Isaacs et al 2011).…”

Potential for green microalgae to produce hydrogen, pharmaceuticals and other high value products in a combined process

“…They can be valuable fresh or dried in the green water technique or as color additive. “Green water” refers to the feeding technique whereby algae are added to the organisms’ environment as a suspension (Neori, 2011). Use of algae in the first-feeding process of aquatic animals may enhance the rearing success, including survival, growth and larvae quality (Conceicão et al , 2010; Lavens and Sorgeloos,, 1996; Reitan et al , 1997).…”

Mass Cultivation of Freshwater Microalgae☆

“…For example, a scheme for sustainable aquaculture, through the integration of algaculture, has been recently worked out (Neori, 2011). The technologies that will be needed, though simple in principle, will require a thorough understanding of the biology of each organism and of the nutrient recycling processes involved.…”