The extraction of organic matter from intensive aquaculture systems is one of the main concerns to minimize the environmental impact of this activity. In the specific case of IMTA systems, various types of organisms are used to successfully perform this task. However, knowing the percentages of organic matter removal of the different extraction species is essential for the dimensioning and evaluation of IMTA systems. For this purpose, researches in the St. Andrews Biological Station in St. Andrews, Canada, carried out laboratory and field experiments to determine the absorption efficiency of the blue mussels and its potential as organic matter extractive species in IMTA. In the laboratory the diets tested were: two algal diets (a commercial spat and a diatom formula), two salmon farm diets and salmon feces, meanwhile in the field test the total particulate matter from the salmon cages was tested.
The absorption efficiency obtained for the different kind of diets were 87, 81, 90, 86 and 54%, for commercial spat formula, commercial diatom diet, salmon feed, salmon feces and total particulate matter from salmon cages. These results recommend that the blue mussels have the capacity of absorbing those waste produced from the salmon cages and represent optimal candidates as organic matter extractive species in IMTA systems with salmon.
For more details, see Reid et al. (2010) Absorption efficiency of blue mussels (Mytilus edulis and M. trossulus) feeding on Atlantic salmon (Salmo salar) feed and fecal particulates: Implications for integrated multi-trophic aquaculture. Aquaculture 299, 165-169.