WWW.WAS.ORG • WORLD AQUACULTURE • JUNE 2018 55 Portugal has a coastline of 2,830 km, including 942 km of the mainland, 667 km in the Azores Islands and 250 km in Madeira Island, which also includes the Desertas, Selvagens and the Porto Santo islands. Portugal has the eleventh largest Exclusive Economic Zone in the world and the largest in the European Union, with an area of about 1,656,000 km2. The continental shelf of Portugal is about 20,141 km2 and is located in an ecological transition zone with high marine biodiversity. Shellfish Farming in the Algarve The Algarve is a region of the Portuguese mainland bordered to the west and south by the Atlantic Ocean. The coastline north of Cape St. Vincent, open to the dominant maritime agitation (NW quadrant) of the Atlantic Ocean, is windy and affected by high-energy waves. The southern coast of the Algarve is sheltered from the prevailing conditions from the North Atlantic with significant wave heights generally less than 1 m. Winter storms and a southeast facing shore may cause strong sea disturbances but wave heights exceeding 3 m rarely occur (Dias 1988, Costa 1994). The Algarve’s economy has always been closely linked to the sea and fishing has been an important activity since ancient times. Portugal has a long tradition of mollusk farming and freshwater and marine fish production. Among the main species produced in aquaculture in Portugal, bivalves produced in Algarve represents around 53 percent of the total national aquaculture production. The most important species produced in this region are the clam Ruditapes decussatus (2,300 t), common cockle Cerastoderma edule (264 t), Mediterranean mussel Mytilus galloprovincialis (1,200 t), and the Offshore Production of Mediterranean Mussels in Southern Portugal João Araújo, Florbela Soares and Pedro Pousão-Ferreira oysters Crassostrea gigas and Ostrea edulis (650 t, all in 2015). A great part of this production originates from the Algarve region (INE 2015). Production of bivalves is the livelihood of many families and takes an important role in the traditional culture and economy of this region. Bivalve production is mainly carried out in lagoons, namely in the Ria Formosa and Ria de Alvor, and some offshore structures located mainly on Lagos and Armona Island in an Aquaculture Pilot Production Area (APPA). The Aquaculture Pilot Production Area The APPA is a production area created by the Portuguese government, with technical and scientific collaboration of IPMA, located approximately 3 km from the coast of Armona Island. This project has an estimated total production of 9,665 t/yr, of which 5,675 t corresponds to fish production in cages and the remaining 3,990 t to bivalves produced on longlines. This site is characterized by highly oxygenated water throughout the water column and an average salinity of 36 ppt throughout the year. The average temperature of the sea oscillates between 15 C in winter and 22 C in summer, with no significant differences with depth. The maximum depth in this area is around 22 m. The dominant sea currents come from the west (Atlantic) and are associated with calm sea conditions concerning current velocity and wave height. Nevertheless, some episodes of maritime agitation may occur, when wave heights may reach (CONTINUED ON PAGE 56) FIGURE 1. Longline system in the Aquaculture Pilot Production Area (APPA). FIGURE 2. Mussel longline in the Aquaculture Pilot Production Area. Photo: Pedro Pousão-Ferreira. The Algarve’s economy has always been closely linked to the sea and fishing has been an important activity since ancient times. Portugal has a long tradition of mollusk farming and freshwater and marine fish production.
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