Marine research, resources and conservation in the Azores

Abstract

ABSTRACT1. A history of marine research on the Azores is outlined. Until two decades ago most oceanic and littoral marine studies had been carried out by foreign scientists. Studies by Azorean scientists started to increase in the early 1980s when the University of the Azores was created.2. Ocean circulation in this part of the Atlantic is described as a background for biogeography and diversity. The picture emerges that Azores is a 'meeting point' for shallow water marine fauna and flora of different origins.3. The species composition of one of the best studied groups of organisms, the fish, is compared between locations in the northeastern Atlantic. The work on fish is also compared with other well studied groups (algae and hydroids) to highlight the interest of the Azores as a natural biogeographical experiment.4. Studies of marine resources began less than two decades ago. The development of demersal fisheries is described focusing on the switch from small-scale artisanal fishing to more commercial fisheries.5. Conservation of species and legislation in force for molluscs, crustaceans, fishes, marine turtles, seabirds and marine mammals are summarized.6. Protected marine areas already designated are defined, as well as new areas recommended. 7. The paper concludes with a discussion of current threats and future management strategies.

Historical population dynamics and demography of the eastern Atlantic pomacentrid Chromis limbata (Valenciennes, 1833)

“…Although dominant average ocean current circulation reaches the Northeastern Atlantic islands from the west, the marine littoral fauna and Xora of the temperate Macaronesia (Azores, Madeira, and Canaries) share aYnities with the eastern coasts of the Atlantic and the Mediterranean (Boury-Esnault and Lopes, 1985;Brito et al, 2001;Brito and Ocaña, 2004;Gofas, 1990;Lloris et al, 1991;Prud'homme van Reine, 1988;Weerdt, 1989;Wirtz and Martins, 1993). This is probably the result of episodic anomalies of the water movements described above (Santos et al, 1995), and of the temperate conditions that the northwest African upwelling confers to these islands.…”

“…In contrast, little is known about genetic relationships between populations of the Macaronesian islands (Azores, Madeira, Canaries, and Cape Verde; Almada et al, 2005;Guillemaud et al, 2000). These isolated oceanic islands constitute interesting model systems for the study of colonization processes, as several climatic and oceanographic phenomena have played a major role in the history of the ichthyofauna of these islands (Almada et al, 2001;Miller, 1984;Santos et al, 1995;Zander, 1980). During the Pliocene, the eastern Atlantic experienced a progressive cooling that reached its extreme with the Pleistocene glaciations (Adams et al, 1999;Briggs, 1996).…”

“…The sea surface temperatures in the Azores region experienced a small cooling (2-3°C) (Crowley, 1981). Several authors (Briggs, 1974;Miller, 1984;Santos et al, 1995) suggested that this drop in sea surface temperatures has probably resulted in mass extinctions of littoral Wsh at the Azores, and that most of the organisms now present would have recolonized the islands after this glaciating event from some southern regions such as Madeira.…”

“…The Northeastern Atlantic current system is dominated by the Gulf Stream, which splits into two main branches, the North Atlantic Current (Xowing north) and the Azores Current (Xowing east). Close to the Azores islands, each of these currents divides into two branches, one of which Xows south, feeding the Madeira and Canaries currents (Santos et al, 1995;Stramma, 1984). This multibranch system is even more complex due to seasonal variations of the mean current directions, and as it is a source of meanders and eddies (Santos et al, 1995;Stramma, 1984).…”

“…Close to the Azores islands, each of these currents divides into two branches, one of which Xows south, feeding the Madeira and Canaries currents (Santos et al, 1995;Stramma, 1984). This multibranch system is even more complex due to seasonal variations of the mean current directions, and as it is a source of meanders and eddies (Santos et al, 1995;Stramma, 1984). Although dominant average ocean current circulation reaches the Northeastern Atlantic islands from the west, the marine littoral fauna and Xora of the temperate Macaronesia (Azores, Madeira, and Canaries) share aYnities with the eastern coasts of the Atlantic and the Mediterranean (Boury-Esnault and Lopes, 1985;Brito et al, 2001;Brito and Ocaña, 2004;Gofas, 1990;Lloris et al, 1991;Prud'homme van Reine, 1988;Weerdt, 1989;Wirtz and Martins, 1993).…”