Information on the status of freshwater fishes in Portugal is good. A paper on freshwater fish and their conservation in Portugal was published in 1995 (Ref: 11237).
The Iberian peninsula lies in the Mediterranean Subregion of the Holarctic. It forms the Lusitanian biogeographic region. The Central (Douro, Tejo and Sado basins) and Southern (Guadalquivir, Guadiana and Mira basins) sectors of this region are shared by Spain and Portugal.
Four different vegetation zones can be recognised in Portugal (Noirfalise, 1987): 1. thermo-Mediterranean (south and southwestern coasts and the River Guadiana basin); 2. meso-Mediterranean ( southern inland areas, west coast, River Tejo basin and the inland part of the basin of the River Douro); 3. supra-Mediterranean (central and northern inland areas); 4. Ibero-Atlantic oak forests (northwestern Portugal). Summer dryness increases from northwestern Portugal eastwards and southwards. In inland southern and central areas most small and medium-sized rivers are dry for three or four months each year. An ancient chain of mountains separates the basins of the Rivers Tejo and Guadiana which marks the boundary between the Central and Southern sectors. However, recent changes (canals, river captures during winter floods etc.) have allowed some fish to move from one sector to another, though such species are rare outside their original area of distribution. Most of the Portuguese species of native Cyprinidae and one of the two species of Cobitidae are Lusitanian endemics.
Despite their high level of endemicity, Portuguese species are not given adequate protection. Pollution, particularly in the industrialised coastal areas, frequently results in mass mortalities. Other threats include sand extraction, inadequate fish passes in dams, and the introduction of exotic species (Almaca, 1983, 1988a). In some areas overfishing is a threat. Inadequate fish passes mainly affect migratory species such as sturgeon, lampreys and shads. The River Tejo is highly polluted from metallurgy works, paper mills, oil refineries and soap works. Pollution of the River Guadiana seems to have been much reduced (Almaca, 1988b). Urban pollution by domestic sewage is very great in the estuaries of these two rivers. Destruction of spawning areas and turbidity caused by sand extraction is common all over Portugal. Finally, in the past century alone 10 or 11 species have been introduced to Portuguese waters. One species, Lepomis gibbosus, has become a pest in southern basins, displacing native cyprinids in tributaries of the Tejo and Guadiana.
Contact: Carlos Almaca, Museu Bocage, Departamento de Zoologia e Antropologia, and Centro de Fauna Portugeusa, Faculdade de Ciencias, Rua da Escola Politecnica, 1200 Lisboa, PORTUGAL.
|Geography and Climate
Portugal is located in Southwestern Europe, bordering the North Atlantic Ocean, west of Spain.
Area - comparative: slightly smaller than Indiana. Total land boundary is 1,214 km, border country is Spain 1,214 km.
Climate is maritime temperate; cool and rainy in north, warmer and drier in south. Terrain consists of mountainous north of the Tagus, rolling plains in south. Elevation extreme has the
lowest point in Atlantic Ocean 0 m and highest point in Ponta do Pico in Azores 2,351 m. Natural resources are fish, forests (cork), tungsten, iron ore, uranium ore, marble. Land use: arable land: 26%, permanent crops: 9%, permanent pastures: 9%, forests and woodland: 36%,
other: 20% (1993 est.). Irrigated land: 6,300 sq km (1993 est.). Natural hazards in Azores subject to severe earthquakes.
Environmentâ€”current issues: soil erosion; air pollution caused by industrial and vehicle emissions; water pollution, especially in coastal areas.
Geographyâ€”note: Azores and Madeira Islands occupy strategic locations along western sea approaches to Strait of Gibraltar.
Ref. Anonymous, 1999