Baía dos Tigres - The dynamic of the process

Abstract

Baía dos Tigres is a well-known sandbank in Angola, referred to since the 15th century when the Portuguese navigators passed there in 1488, on the voyage that allowed them to round the Cape of Good Hope, in southern Africa. It is a phenomenon of a sedimentary nature and therefore it is linked to the availability of solid flow carried by the drift current coming from the South. However, several changes in its condition have been recorded over the centuries. It has shifted from being a sandbank (restinga) and an island, this latter occurring when the isthmus that connects it to the mainland broke, becoming a restinga again when it reestablisheb itself. In March 1962, a huge storm at sea destroyed the fragile structure connecting the land to the coast and since then, precisely 60 years ago, Baía dos Tigres became an island, being separated from the coast in a way that seemed definitive. The observation and analysis of the satellite images used in this work seem to suggest that a setback is beginning to appear, since Baía dos Tigres may be starting to reconnect to the mainland. If this occurs, there is the possibility for Angola to have again a true fish hatchery where countless varieties of fishes and molluscs find unique conditions for spawning. Those partially closed conditions, with waters sufficiently oxygenated to generate excellent biological environment for spawning, are of great importance for the future of fish industry in the country. If those conditions are restored, the zone will be protected from the direct action of storms and the speed of currents, covering an area of more than 250 km2. This article makes an up-date of the situation, based on the analysis of satellite images currently available.