AQUACULTURE IN MOROCCO: GROWTH PERFORMANCE OF CRASSOSTREA GIGAS IN TWO LAGOONS ON THE ATLANTIC SHORE

Marine aquaculture was introduced in Morocco in the 1950s and has since known little development. Oyster farming was initiated in the lagoon of Oualidia and currently constitutes 72% of Moroccan aquaculture production. For this study the pacific oyster Crassostrea gigas was grown using rack-and-bag culture at two sites; Oualidia lagoon and Sidi Moussa lagoon, a potential new aquaculture site, both situated on the Atlantic Moroccan shore. The aim of this study was to examine the growth performance, condition and survival rates of the pacific oyster grown in the two lagoons. Samples were taken at a monthly frequency. Growth rates, condition and mortality were investigated in both sites from August 2014 to July 2015. Temperature, Salinity, Total Suspended Solids in the water, Nitrates and Phosphates were monitored at both sites at the same time. Results show that at the end of the experiment, significantly greater length was observed for oysters reared at SM reaching an average of (123.2 mm). Dry weight of oysters at OA were significantly lower compared to oysters reared at SM from February to July 2015, the maximum dry weight observed at the end of the experiment was (4.73g) at OA and (5.95g) at SM. The Condition index ranged from 3.19 to 8.97 and from 4.04 to 7.62 at OA and SM respectively. Cumulative mortality recorded in SM was significantly lower than in OA. The good growth performance and the high survival of the Pacific oyster lead to the conclusion that the lagoon of Sidi Moussa can be a new potential site for aquaculture production