Amazon Reef

It is one of the largest known reef systems in the world, with scientists estimating its length at over 1,000 kilometres (600 miles), and its area as over 9,300 km2 (3,600 sq mi).

[8] The reef's area extends as far as 120 km (75 mi) offshore,[9] and is estimated to lie in waters ranging from 30 to 120 metres (100 to 400 feet) deep.

Southern sections of the reef, which are covered by the Amazon's plume only three months a year on average, are more populated with diverse coral-centric life, where photosynthesis can occur.

[5] It is believed that single-celled organisms are central to the reef's ecosystem, providing the main source of nutrients to sponges, corals and other inhabitants.

[18] Further evidence also appeared in 1977, when reef fish were first sighted in the area,[11][19] and in 1999, when Caribbean-native coral species were found in isolated regions near the Amazon Delta.

[9] However, no major study into the existence of a reef system occurred until 2012, when an international research team of over 30 oceanographers,[13] led by Rodrigo Moura of the Federal University of Rio de Janeiro, and including patrons from the University of Georgia,[11] conducted a survey of the area aboard the RV Atlantis.

The survey was mostly based on findings from the 1970s, including a crude map of the area marked with potential locations of reefs along the Amazonian coast.

[citation needed] Their discoveries and findings were detailed and presented in a research article published in the scientific journal Science Advances in April 2016.

[23] In the past decade, the Brazilian government had sold 80 license blocks to oil energy companies in the region, with an environmental baseline based on "sparse museum specimens".

Map of the Amazon Reef, relative to Brazil , French Guiana and Suriname , with main reef structures highlighted in orange
Satellite image of the mouth of the Amazon River , whose discharge into the Atlantic represents a fifth of the outflow into the Earth's oceans .
Major structures along the inner and outer shelves; laser scale = 20 cm: [ 6 ]
A: sand dunes in the shallowest portion of the reef (60–70 m or 200–230 ft)
B: reef covered by sediments between 70 and 80 m (230 and 260 ft) depth
C: diverse reef community with schools of Paranthias furcifer and bottom dominated by live crustose coralline algae and black corals at 130 m (430 ft) depth
D: deepest portion (220 m or 720 ft) with nearly 100% of live benthic coverage (mostly sponges, octocorals and black corals)
E: a cleaning station of Lysmata grabhami at 110 m (360 ft) depth
F: rhodolith mound built by Malacanthus plumieri at 130 m (430 ft) depth
G: a large snowy grouper (>60 cm total length) at 190 m (620 ft) depth
H: an urchin barren at 130 m (430 ft) depth
The RV Atlantis , upon which the discovery team conducted research