Mussel culture in Galicia (N.W. Spain)

Abstract

This paper describes mussel culture in Galicia (N.W. Spain) based on our previous studies and data obtained from a survey carried out in 1984 on 337 rafts (10% of the total) in the Rias of Arousa, Pontevedra and Vigo. Data are also included on the biology of the cultured mussel, raft characteristics and culture techniques. The raft culture process is divided into four stages: obtaining the seed, growing the seed, thinning out the ropes and transferring the seed onto new ropes and final harvest and sale. These operations differ among the different rias and the zone of the ria. Therefore seed can be obtained directly from the coastal rocks or from collectors over the rafts, or both. Seed is attached to ropes that will be thinned out twice or three times before commercial size is reached. Collectors are placed in spring and the mussel seed ropes are placed in the sea throughout the whole year, but specially from November to March. The thinning out process is usually carried out between June and October. The mean surface area of the rafts is 261 m 2 in the Ria de Vigo, 352 m 2 in the Ria de Pontevedra and 369 m 2 in the Ria de Arousa, with an increase in the last of almost 25% since 1974. The declared production per ha and year reaches 48.0 t/raft in the Ria de Arousa, 46.9 t/raft in the Ria de Pontevedra and 33.2 t/raft in the Ria de Vigo, while production per m 2 of raft is 130 kg, 133 kg and 127 kg, respectively.