The Biological Reserve, which covers 17,104 hectares (42,260 acres), was established on 12 March 1990.
[1]
It lies in the municipalities of
Bombinhas
,
Florianópolis
and
Governador Celso Ramos
of the state of Santa Catarina.
[2]
The reserve is a transition region for seaweed flora, including organisms typical of both temperate and tropical regions.
[3]
The reserve is close to the Subtropical Convergence where the
Brazil Current
from the north converges with the
Falkland Current
from the south. The surface waters are dominated by the Tropical Shelf Water while below 20 metres (66 ft) in depth the water is from the South Atlantic Central Water.
[4]
The Arvoredo archipelago (27°17' S; 48°28' W) is formed by three islands (Arvoredo, Galés and Deserta) and a rocky outcrop (São Pedro). The archipelago lies over the continental platform and is characterized by the presence of
Precambrian
crystalline rock shorelines. The depth throughout the archipelago varies from 5 to 25 metres (16 to 82 ft), rarely deeper than 30 metres (98 ft).
Arvoredo is the largest island 318.6 hectares (787 acres), with highly accident relief and steep coastlines providing sites sheltered from the dominant northern quadrant winds and from the strong southern winds. Along its southern rocky-shore SCUBA diving is permitted, as the shoreline in this area lies outside of the reserve limits.
Galés Island 39.7 hectares (98 acres), the closest to the continent, has the same rocky formation as Arvoredo island, with few scarps and two small islets divided by a 27 metres (89 ft) deep channel from the main island.
Deserta Island 13.2 hectares (33 acres) has a well scarped shoreline which is influenced by strong waves due to its southwest-northeast orientation; its relief is elevated in the northern area, with a strong decline southwards.
A few outcrops can be found in the region, such as Pedra Noceti, Parcel do Boi and Parcel da Deserta. The rocky habitat is characterized by many cavities formed by large boulders and medium-small sized pebbles covered with
seaweed
.
