Open AccessThe use of aquaculture effluents in spray culture for the production of high protein macroalgae for shrimp aqua-feeds
Author(s) -
B. Greg Mitchell,
Amir Neori,
Charles Yarish,
D. Allen Davis,
Tzachi M. Samocha,
Louis Guttman
Publication year - 2013
Language(s) - English
Resource type - Reports
DOI - 10.32747/2013.7597934.bard
Subject(s) - fish meal , shrimp , aquaculture , commercial fish feed , fishery , shrimp farming , fish farming , effluent , productivity , monoculture , stocking , biology , environmental science , fish <actinopterygii> , ecology , environmental engineering , macroeconomics , economics
The FAO has projected a doubling in world demand for seafood during the 21 ed from aquaculture of marine fish and shrimps fed primarily on fishmeal-based aquafeeds. However, current practices of high intensity monoculture of shrimp in coastal ponds and fish in offshore pens have been strongly criticized as being ecologically and socially unsustainable. This view derives from un- checked eutrophication of coastal marine ecosystems from fish farm effluents, and the destruction of coastal estuarine ecosystems by shrimp farm constructions, plus aquaculture’s reliance on wild-caught small fish - which are excellent food for humans, but instead are rendered into fishmeal and fish oil for formulating aquafeeds. Fishmeal-sparing and waste- reduction aquafeeds can only delay the time when fed aquaculture product are priced out of affordability for most consumers. Additionally, replacement of fishmeal protein and fish oil by terrestrial plant sources such as soybean meal and oil directly raises food costs for human communities in developing nations. New formulations incorporating sustainably-produced marine algal proteins and oils are growing in acceptance as viable and practical alternatives. This BARD collaborative research project investigated a sustainable water-sparing spray/drip culture method for producing high-protein marine macrophyte meals for incorporation into marine shrimp and fish diets. The spray culture work was conducted at laboratory-scale in the USA (UCSD-SIO) using selected Gracilariaand Ulvastrains isolated and supplied by UCONN, and outdoors at pilot-scale in Israel (IOLR-NCM) using local strains of Ulvasp., and nitrogen/phosphorus-enriched fish farm effluent to fertilize the spray cultures and produce seaweed biomass and meals containing up to 27% raw protein (dry weight content). Auburn University (USA) in consultation with TAMUS (USA) used the IOLR meals to formulate diets and conduct marine shrimp feeding trials, which resulted in mixed outcomes, indicating further work was needed to chemically identify and remove anti-nutritional elements present in the IOLR-produced seaweed meals.