The rearing of the Mediterranean mussel, Mytilus galloprovincialis Lamarck, 1819, has been tested for the first time in an innovative Integrated Multitrophic Aquaculture system (IMTA) in offshore, as part of the EU-funded PATINER project. This farming system could solve several problems including the high mussels mortality observed in Bizerte lagoon especially during summer season and reducing the environmental impact of finfish mariculture cages.
The purpose of this study is to evaluate for the first time the growth performance of the Mediterranean mussel in open sea in an IMTA system in Monastir Bay.
The IMTA system is consisted of several species occupying different trophic levels in the same site of production: fed species (finfish: sea bream and sea bass) combined with filter species such as oysters, mussel and clams; deposit feeders such as sea cucumbers, sea urchin and inorganic extractive species such as algae.
Juvenile mussels aged from 4 to 6 months were used for culture in nylon bags. Every two to three months mussels were randomly sampled and then transferred to the laboratory where the biometric measurement (length, weight), Condition Index (CI) and mortality were assessed. Environmental parameters (temperature, salinity, dissolved oxygen, pH and Chlorophyll-a) were also monitored.
At the end of the rearing period (i.e. 10 months) the preliminary results of this study showed an increased growth of mussel. In fact, growth was increased from 35 ± 5,34 mm to 45 ± 6,02 mm (1,08 mm month-1) . Likewise, weight was increased from 4,8 ±1,88 to 8,69 ± 3,43g ( 0,4 gmonth-1) with a specific weight growth rate around 0.17%/day.