Formigas Islets ( ; literally, ''Islets of the Ants''), sometimes referred to as the Formigas Bank, are a group of uninhabited rocky outcroppings in the eastern group of the
Azores
The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...
archipelago
An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...
, an autonomous region of
Portugal
Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...
. The bank is located northeast of
Santa Maria and southeast of
São Miguel, covering a surface area of approximately . The submerged
Dollabarat Reef is in the same area. The only structure on the islets is a
lighthouse
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways.
Ligh ...
located on Formigão (''Big Ant''), the largest
islet
An islet ( ) is generally a small island. Definitions vary, and are not precise, but some suggest that an islet is a very small, often unnamed, island with little or no vegetation to support human habitation. It may be made of rock, sand and/ ...
.
History

The Formigas were discovered by Portuguese explorers
Diogo de Silves and
Gonçalo Velho Cabral in 1431 during their journey to
Madeira
Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...
. The islets were neglected due to the contemporaneous discovery of the neighboring inhabitable islands of Santa Maria and São Miguel. In the 16th century, Portuguese chronicler
Gaspar Frutuoso reported on the Formigas' rich marine life.
The Formigas served as both an aid and hindrance to navigation from their discovery well into the 20th century. On 8 April 1832, the British ship ''
Zyllah'' wrecked on a subsurface rock at the Formigas and its crew had to be rescued the next day by the British merchantman ''
Morley''.
Nearly ninety years later on 16 June 1921, the
Greek cargo ship ''
Olympia'' ran aground and wrecked at Formigas; the crew survived.
The islets have long garnered scientific and commercial interest. In 1886, the
Italian ship ''Corsaro'' visited the Formigas Islets, dredging the area for the first time for scientific research purposes.
Prince Albert I of Monaco's ''Princess Alice'' expedition also visited the islets in 1895 to investigate the marine life, for both scientific and commercial fishery purposes.
Since 4 April 1988, the Formigas Bank has the status of Nature Reserve and is protected by a decree of the
Legislative Assembly of the Azores (Regional Legislative Decree Nº11/88/A). It is also considered a European Site of Community Importance (Rede Natura 2000). The habitats protected by the Azorean decree include the area from the emerged islets to depths of more than , yet this has not stopped incidents of commercial fishing. Consequently, the area is regularly patrolled by a Portuguese naval vessel based in
Ponta Delgada
Ponta Delgada (; ) is the largest municipality (''concelho'') and executive capital of the Autonomous Region of the Azores in Portugal. It is located on São Miguel Island, the largest and most populous in the archipelago. As of 2021, it has 67,2 ...
.
Since 16 June 2008, the Formigas Islets and neighboring Dollabarat Reef have been recognized as a
Ramsar Convention
The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar site, Ramsar sites (wetlands). It is also known as the Convention on We ...
wetland
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
under the name ''Ilhéus das Formigas e Recife Dollabarat''.
Formigas Lighthouse
The Formigas Lighthouse () is located on Formigão, the largest islet of the Formigas. The current beacon is a stone tower painted white. As the base of the tower is at an elevation of about above sea level, the beacon is at above sea level. The lighthouse's signal is visible from away on clear days, although there have been reports of seeing it from the southeastern part of São Miguel and the northeastern part of Santa Maria. In rough seas, waves completely immerse the tower.
As early as 1883 the Portuguese government formally recognized the dangers posed by the Formigas to navigation and proposed building a lighthouse on the islets, but nothing was constructed at the time. On 2 March 1895, at the General Meeting of the
Autonomous District of Ponta Delgada, the District initiated construction of lighthouses on São Miguel and Santa Maria. Because of this, and also due to the technical difficulties of building a lighthouse in that era in a place so inhospitable as the Formigas, construction of a lighthouse on the islets themselves was further delayed.
Finally, in the summer of 1948 the Portuguese government began a complex operation to build a lighthouse on Formigão. In order to land personnel and equipment on the islet, the workers first had to break away subsurface rocks and build a
wharf
A wharf ( or wharfs), quay ( , also ), staith, or staithe is a structure on the shore of a harbour or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more Berth (mo ...
. Despite various interruptions to the work due to rough seas and inclement weather, in 36 days the workers managed to build a small beacon. In 1962, the
Portuguese Navy's
lightship ''
NRP Almirante Schultz'' anchored at the Formigas and was used as a work base for renovating and modernizing the lighthouse. In the succeeding years the lighthouse was further modernized; the beacon now runs on
solar power
Solar power, also known as solar electricity, is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Solar panels use the photovoltaic effect to c ...
and its old
acetylene
Acetylene (Chemical nomenclature, systematic name: ethyne) is a chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is u ...
lamp has been replaced with a newer model.
Geography

The islets are composed of
basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
flows that occurred approximately 4 million years ago, although calcareous fossiliferous sediments dating to 4-6 million years ago have been discovered. The bank extends for from northwest to southeast and is wide. Due to strong currents and frequent large swells, the linear rock outcroppings lack any terrestrial flora or fauna. Along the archipelago's perimeter, the seabed drops steeply to a depth of on either side, and gently at the northern and southern tips. The area of the bank referred to as the
Dollabarat Reef is an area of shallower gradient, situated along the southwest of the Formigas Islets.
''Formigas'' is Portuguese for ants, as the small and dispersed rocks resemble scattered ants. The largest islet Formigão has a maximum altitude of above sea level. Generally the islets are useful for navigation and visible up to away on clear days, but during inclement weather a ship can run aground on the rocks without even seeing the lighthouse.
Biome
The Formigas Bank is essentially a
submarine volcano inhabited by deep-dwelling marine species such as coral and sponges.
[SIARAM (September 2010)] The volcanic cone is delimited approximately by the Formigas islets of the northwest and Dollabarat Reef to the southeast.
[ In the ancient crater there is a rich community of species common to the Azores. Among the species typical of the area are wrasse ( Mediterranean rainbow wrasse and ornate wrasse]), damselfish, sergeant fish (yellow and black), grouper, Mediterranean parrotfish, and the emblematic Atlantic goliath grouper, serranidae
Serranidae is a large family (biology), family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, ...
and barred hogfish.[ Alongside these are African threadfish and longbill spearfish, pelagic predators that also reside in the bank, and migratory species like manta ray and ]whale shark
The whale shark (''Rhincodon typus'') is a slow-moving, filter feeder, filter-feeding carpet shark and the largest known Extant taxon, extant fish species. The largest confirmed individual had a length of . The whale shark holds many records for ...
.[
The base and surface of the volcano is covered in various types of black coral, soft corals, sponges, and other invertebrates, as well as various ]algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
, forming a mosaic of micro-habitats.[ The geological differences of the Formigas Islets and Dollabarat Reef relative to the rest of the Azores are accentuated by the types of flora present there. The Formigas and Dollabarat both have an elevated biomass of ]brown algae
Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate ...
considered unique to the Azores; the fields of kelp are situated between and below the crater at the Formigas, while at Dollabarat the brown algae
Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate ...
is located along the reef's flanks.[
]
References
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{{Azores Islands
Islets of the Azores
Ramsar sites in Portugal
Uninhabited islands of Portugal
Archipelagoes of Portugal