Mangrove

Mangroves are “shrubs and trees that grow in dense thickets or forests along tidal estuaries, in salt marshes, and on muddy coasts; and that characteristically have prop roots – exposed supporting roots” [1]. As NOAA states, “there are about 80 different species of mangrove trees” (though only 54 true species) which all “grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate,” and “cannot withstand freezing temperatures,” and thus grow in “tropic or subtropic latitudes” [4], [6].

They “project above the mud” with “small openings through which air enters,” and “serve as a buffer between marine and terrestrial communities and protect shorelines from damaging winds, waves and floods,” maintaining coastal integrity and safety while also “filtering pollutants and trapping sediment from the land” [1].

The Editors of Encyclopaedia Britannica mention that mangroves can be split into different types, with Gulf Coast mangroves being the “common mangrove” and the “black mangrove,” and the only other United States mangrove is the white mangrove, where the common mangrove has “long, opposite, oval or elliptic” leaves that are “thick and leathery,” and “pale yellow flowers.” The black mangrove differs, with “long, opposite, oblong, or spear-shaped” leaves with a “green and glossy” upper surface and “whitish or grayish” lower surface and “small white flowers” [1]. The white mangrove differs from both as it “often grows farther inland with no outstanding root structures” [7].

Mangroves live in wetlands that “are normally classified into six types on the basis of the geophysical, geomorphological and biological factors,” being either “(a) river dominated, (b) tide dominated, (c) wave dominated, (d) composite river and wave dominated, (e) drowned bedrock valley mangroves and (f) mangroves in carbonate settings." Other varieties of mangroves not mentioned before have a range of bark colors, form “whitish to greyish or yellow-green” to “dark grey or pale pink” to “pale grey and brown” and “reddish,” with mangroves varying between these colors and more extreme, darker grays and browns [2].

In a broader sense, mangroves fall under estuaries, or partially enclosed water bodies that are always near the coastline, except for “freshwater estuaries created when a river flows into a freshwater lake” [3]. Freshwater from rivers and streams mix with salt water from the ocean, combining to “become brackish, or slightly salty but not as salty as the ocean” [3]. Estuaries are referred to as the transition from land to sea, with shifting tides, and are distinguishable with the “rich array of habitats usually determined by the local geology and climate” such as “salt marshes, mangrove forests, mud flats, tidal streams, rocky intertidal shores, reefs, and barrier beaches” [5]. These habitats oftentimes keep them protected from the full force of severe weather or turbulent waters during storms, and estuaries will also act as a last line of defense and coastal stabilization for humans as well.

As these habitats can be classified separately through the labels 'marsh,' 'mangrove,' 'wetland' (for the combination of mud flats and tidal streams), 'shoreline,' and 'sea,' the label of 'estuary' was not considered for the Atlantis dataset. The term is too broad and individual labels capturing specific details of estuaries are more effective for training artificial intelligence.

References

[1] Britannica, T. Editors of Encyclopaedia. (2019, April 24). mangrove. Encyclopedia Britannica. Retrieved (2021, July 14), from https://www.britannica.com/plant/mangrove

[2] Durst, P. B. (2007). Trees and shrubs of the Maldives. Retrieved (2021, July 14), from http://www.fao.org/3/ai387e/AI387E06.htm

[3] National Geographic Society. (2012, August 23). Estuary. Retrieved (2021, July 21), from https://www.nationalgeographic.org/encyclopedia/estuary/

[4] National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce. (n.d.). What is a Mangrove Forest? Retrieved (2021, July 14), from https://oceanservice.noaa.gov/facts/mangroves.html

[5] National Oceanic and Atmospheric Administration (NOAA). (2021, February 26). Estuarine Habitats. Retrieved (2021, July 21), from https://oceanservice.noaa.gov/education/tutorial_estuaries/est06_habitats.html

[6] The Ocean Portal Team & Feller, C. (2018, April). MANGROVES. Smithsonian Ocean Portal: Find Your Blue. Retrieved (2021, July 13), from https://ocean.si.edu/ocean-life/plants-algae/mangroves

[7] United States Environmental Protection Agency (US EPA). (n.d.). Mangrove Swamps. Retrieved (2021, July 13), from https://www.epa.gov/wetlands/mangrove-swamps