Trindade and Martim Vaz: Archipelago and Ecoregion (Brazil)

Trindade and Martim Vaz: Archipelago and Ecoregion (Brazil)

Tue, 05/23/2023 - 19:47

Trindade and Martim Vaz is an archipelago situated east of the coast of Espírito Santo, Brazil. The archipelago consists of two main volcanic islands and several islets, mainly barren with rugged terrain. The islands occupy the Trindade and Martim Vaz Islands tropical forest ecoregion.

Trindade and Martim Vaz

Trindade and Martim Vaz is an archipelago at the easternmost point of Brazilian territory, situated approximately 1,140 km (700 mi) eastward from the coast of Espírito Santo, of which it forms a part.

The archipelago consists of two main islands, several islets, and rocks from volcanic activity deep below the Atlantic Ocean seabed. They are mainly barren with rugged terrain.

The Trindade and Martim Vaz islands were discovered in 1502 by Portuguese navigators led by Estêvão da Gama, and along with Brazil, became part of the Portuguese Empire.

From 1895 to 1896, Trindade was occupied by the United Kingdom until an agreement with Brazil was reached. During the period of British occupation, Trindade was known as South Trinidad.

Trindade and Martim Vaz archipelago has historical significance as a strategic outpost and has been the subject of scientific expeditions due to its unique biodiversity and geological features.

The islands are remote and uninhabited, except for a small rotating military garrison stationed on Trindade Island. Access to the archipelago is restricted, and permission is required to visit the islands.

In 2002, the Brazilian government declared the archipelago a Natural Monument, which means that it is protected from development and exploitation.

Trindade Island

Trindade is the largest island, with an area of about 10 sq km (4 sq mi). It is an extinct volcanic island known for its unique and diverse ecosystem, including rare plant species and various seabirds.

The island lies about 1,000 km (620 mi) from the continental shelf off the Brazilian coast, more than halfway between Brazil and the Mid-Atlantic Ridge, near the eastern end of the submarine Vitória-Trindade Ridge.

Trindade is a mountainous, desiccated volcanic island with numerous phonolite lava domes and steep-sided volcanic plugs. The highest point is Pico Desejado, reaching an elevation of 620 m (2,030 ft).

Nearby to the northwest is Pico da Trindade at 590 m (1,940 ft) and Pico Bonifácio at 570 m (1,870 ft). Pico Monumento, a remarkable peak in the form of a slightly inclined cylinder, rises from the west coast to 270 m (890 ft).

The island also has several scenic beaches and cliffs. In addition, it hosts a small navy-supported research station.

Martim Vaz Islands

Ilha Martim Vaz is a smaller island about 38 km (24 mi) northeast of Trindade. It covers an area of approximately 0.3 sq km (0.12 sq mi). The island is known for its rocky terrain and sheer cliffs. It is an important seabird breeding site and is home to various species.

The Martim Vaz Islets, though often visible from Trindade, are located approximately 38 - 42 km (24 - 26 mi) to the east. Of volcanic origin, they are considerably smaller than Trindade and include:

  • Ilha da Racha ("Crack Island") or Ilha Martim Vaz, the largest, 175 m (574 feet) high

  • Ilha do Norte ("North Island"), north-northwest of Ilha da Racha, 75 m (246 ft) high

  • Rochedo da Agulha ("Needle Rock"), a flat circular rock northwest of Ilha da Racha, 60 m (200 ft) high

  • Ilha do Sul ("South Island"), south of Ilha da Racha, is a rocky pinnacle

Environment

Trindade and Martim Vaz archipelago experiences a tropical oceanic climate, with an annual mean temperature of 25 °C (77 °F). Daily rain showers, locally called pirajá, generally last about five minutes.

Until around 1850, between 75 - 85% of the island was covered by a forest of Colubrina glandulosa trees, 15 m (49 ft) in height. The introduction of non-native animals and the indiscriminate cutting of trees led to the destruction of the forest, causing heavy erosion on the island, with a loss of about 1 - 2 m (3 - 6 ft) of fertile soil. The effect of this devastation impaired the flow of water with the depletion of several springs.

The island's biodiversity has heavily deteriorated since the second half of the 20th century, with many indigenous species becoming endangered.

The archipelago is Brazil's leading nesting site for the green sea turtle. There are also large numbers of breeding seabirds, including the endemic subspecies of the Great frigatebird (Fregata minor nicolli) and Lesser frigatebird (F. ariel trinitatis), and it is the only Atlantic breeding site for the Trindade petrel. In addition, Humpback whales have been confirmed to use Trindade Island as a nursery.

Trindade and Martim Vaz archipelago is a popular destination for scientists and researchers who study its unique flora and fauna. It is also a popular destination for ecotourism, with visitors drawn to its stunning scenery and abundant marine life.

Trindade and Martim Vaz Islands Tropical Forest Ecoregion

The Trindade and Martim Vaz Islands tropical forest ecoregion comprise the Neotropic ecozone and the Tropical and subtropical moist broadleaf forests biome.

A forest dominated by glandular nakedwood covered 85% of Trindade until the mid-1700s when Portuguese colonists arrived. However, the island's trees were almost eliminated during this period or after. Possible explanations for this die-off involve volcanic gas, overgrazing by the introduced goats, decreased rainfall, or, most likely, fires set by humans.

Small areas today still retain this tree on Trindade. However, characteristic vegetation now consists of the endemic tree fern Cyathea coelandii, which averages 6 m (20 ft) in height, the introduced Peperomia beckeri, grasses, shrubs, and herbs.

Likely the most impressive fauna of the archipelago is the islands' large populations of seabirds. This archipelago is the only place where the great frigatebird—a seabird common in the Indo-Pacific ocean—can be found in the Atlantic.

Although the frigatebird spends most of its life at sea, it is rarely seen swimming since its feathers are not waterproof. Instead of catching their fish, frigatebirds often steal a catch from other seabirds. These other seabirds include the Trindade petrel, red-footed booby, white tern, brown noddy, phoenix petrel, and sooty tern.

Trindade is Brazil's most important nesting ground for green sea turtles, supporting some 1,800 nests yearly on 3 km (1.8 mi) of sandy beach. Peak nesting occurs from January through March.

The native crab, Geocarcinus lagostoma, can be observed throughout the island, from the beaches to the island's highest point, Pico do Desejado.

Avifauna includes Anous minutus (Black Noddy), Anous stolidus (Brown Noddy), Columba livia (Rock Pigeon), Estrilda astrild (Common Waxbill), Fregata ariel (Lesser Frigatebird), Fregata minor (Great Frigatebird), Gygis alba (White Tern), Numida meleagris (Helmeted Guineafowl), Sicalis flaveola (Saffron Finch), Sterna fuscata (Sooty Tern), Sula dactylatra (Masked Booby), and Sula sula (Red-footed Booby).

Protection Status

Trindade and Martim Vaz archipelago has no permanent settlement, though Trindade is visited by researchers and periodically occupied by teams from the Brazilian Navy.

In 1957, the Brazilian Navy established the Oceanographic Station of the Trindade Island (POIT). Since then, there have been frequent expeditions for meteorological observations and attempts to reforest the island.

Brazil's national Marine Turtle Protection and Research Program (TAMAR-IBAMA Project) has also conducted work on the island since 1982 with support from the Navy.

Due to its remoteness from the mainland, rugged terrain, and lack of tourist facilities, the archipelago is practically, if not officially, free of any tourism activities. However, past human interference has led to dramatic biodiversity losses on Trindade Island.

Without any suppression by natural predators, introduced goats, sheep, pigs, feral cats, and mice have flourished in number, causing severe destruction to the island's vegetation and soils.

Many endemic plant and animal species are presently considered extinct. Despite extensive searches, at least 21 plant and 15 animal species previously registered on Trindade have not been found again since 1965.