Growth, mortality and parasitization of mussels cultivated in the Ria de Arousa (NW Spain) from two sources of seed: intertidal rocky shore vs. collector ropes

The cultivation of the mussel, Mytilus galloprovincialis, in the Galician Rias (NW Spain) requires approximately 4600 tonnes of mussel seed every year. Traditionally, this seed is obtained from two different sources: intertidal rocky shore and collector ropes, In this study, the biological performance (growth rate, mortality and parasitization) of mussels from both sources of seed was compared in a cultivation area of the Ria de Arousa, The results from this experiment indicate there is no difference in biological performance between the two types of mussels seed under standard cultivation conditions. Nevertheless, the use of mussel seed from collector ropes is recommended due to their significantly larger size at harvest time. The main deficiency of this type of seed, its high mortality from seeding to thinning out, could be offset by improving the procedure of tying the mussels to culture ropes, (C) 1998 Elsevier Science B.V. All rights reserved.