Multitrophic farming contributes to the reduction of organic waste from fish farms. (Photo: Salud Deudero/IEO)
Multitrophic aquaculture reduces organic waste
Tuesday, March 13, 2012, 16:40 (GMT + 9)
A team of researchers from the Balearic Oceanography Centre of the Spanish Institute of Oceanography (IEO) states that multitrophic aquaculture -- simultaneous production of different species of various trophic levels -- is an effective method to reduce and minimize the organic waste from the activity.
The investigation that led to this conclusion was conducted in collaboration with the Laboratory for Marine and Aquaculture Research (Limia) of the Government of the Balearic Islands and was published in the book called Aquaculture and the Environment.
According to the IEO, the study involved the incorporation of a system made up of filtered Mediterranean mussel (Mytilus galloprovincialis) and variegated scallop (Chlamys varia) into the meagre (Argyrosomus regius) farming cages, at the facilities of Limia in d'Andratx Port.
The researchers assessed the changes in the food web by analyzing the isotopic signal of carbon and nitrogen from different organisms -- mussels, variegated scallop, sea cucumber (Holothuria forskalii), phytoplankton and zooplankton -- and the deposited organic and particulate matter.
In addition, they compared the cage area with other reference stations in d'Andratx Port and in the marine reserve of the bay of Palma.
After studying the temporal, annual and seasonal variability of these parameters, the investigation team failed to demonstrate the efficiency of the filtered organisms in reducing the waste from the fish cages, which increases water quality.
The studies were conducted between 2008 and 2012 under the project 'Integrated aquaculture through multitrophic farming: evaluation of reducing the organic load with the application of stable isotopes."
This initiative was funded by the Advisory Board for Mariculture (Jacumar) of the Ministry of Environment and Rural and Marine Affairs (MARM).
Photo Courtesy of FIS Member IEO - Instituto Español de Oceanografía (Oficina central)
By Analia Murias