Amazonia marine ecoregion
Amazonia marine ecoregion | |
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![]() The Amazon Reef, discovered only in 2012, extends across the ecoregion. | |
![]() Marine ecoregion boundaries (red line) | |
Location | Brazil |
Coordinates | 0°12′N 48°00′W / 0.2°N 48°W |
Type | marine ecoregion |
Part of | Tropical Atlantic realm, North Brazil Shelf province |
Surface area | 384,566 square kilometres (148,482 sq mi)[1] |
The Amazonia
Physical setting
The ecoregion is bounded on the west at the Brazil-French Guiana border, where the North Brazil Current splits splits - part continuing northwest as the Guiana Current, part turning north. 850 miles to the southeast, the ecoregion transitions to the
The continental shelf is relatively smooth and shallow, with a drop on the shelf about half-way to the north. The deepest point is −2,047 metres (−6,716 ft), and the average is −49 metres (−161 ft).[4] 38% of the ecoregion is less than 200 meters in depth, and 54% is greater than 1,000 meters. Underneath the freshwater outflow of the Amazon is a carbonate reef structure, the Amazon Reef. This deep reef is colonized by sponges and other filter feeders, under conditions of low light and dense particulates.[6]
Currents and climate
Flowing northwest through the ecoregion is the warm
A large outflow of fresh and brackish water from the Amazon mouth - the Amazon river plume - extends through the middle of the Amazonia ecoregion, being pulled north by the NBC. Combined with rainfall this lowers the salinity of the ecoregion's waters, to levels that average 35-36.75 ppm. Surface temperatures range from 22–29 °C (72–84 °F).[10]
Animals / Fish
The coast is dominated by the Amazon delta and extensive mangrove forests. The inlets, swamps and lagoons provide shelter, food, and breeding habitat for birds, invertebrates and fish.[1] Offshore, the continental shelf supports soft mud-bottom communities.[1] Aside from the Amazon Reef structure, the bottom is mostly sand, mud and gravel in the deeper water.[11]
Near shore, the most important commercial fisheries are for shrimp, primarily Southern brown shrimp (Farfantepenaeus subtilis) and Red spotted shrimp (Farfantepenaeus brasiliensis).[12]
Conservation status
Many of the terrestrial protected areas on the coast have marine components, such that about 12% of the ecoregion is protected, including:[4]
- Cabo Orange National Park. Marine zone extends 10 miles out from extensive wetlands (a RAMSAR site).[13]
- Algodoal-Maiandeua Environmental Protection Area. Two islands at the mouth of the Amazon, with mangroves important for their role as nurseries for fish, mussels, shrimps, oysters, turtles, crabs and other marine life.
References
- ^ a b c d "Setting Geographic Priorities for Marine Conservation in Latin America and the Caribbean" (PDF). The Nature Conservancy. Retrieved June 30, 2022.
- ^ "North Brazil Shelf". One Shared Ocean. Retrieved June 30, 2022.
- ^ Spalding, MD; Fox, Helen; Allen, Gerald; Davidson, Nick. "Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas". Bioscience. Retrieved June 30, 2022.
{{cite web}}
: CS1 maint: multiple names: authors list (link) - ^ a b c "Amazonia". Digital Observatory for Protected Areas (DOPA). Retrieved June 30, 2022.
- ^ "Amazonia". MarineRegions.org. Retrieved July 8, 2022.
- PMID 27152336.
- ^ "North Brazil Current". University of Miami. Retrieved June 30, 2022.
- S2CID 257058194.
- ^ "The Guiana Current". University of Miami. Retrieved June 30, 2022.
- ^ "Guianan Current". Encyclopedia Britannica. Retrieved July 1, 2022.
- . Retrieved July 1, 2022.
- ^ "Estuary & Amazon Coast". Amazon Waters. Retrieved July 14, 2022.
- ^ "Cabo Orange National Park - Brazil" (PDF). RAMSAR. Retrieved July 2, 2022.