Betsiboka River Delta in Madagascar •

Today’s Image of the Day from NASA Earth Observatory features the reddish-brown waters of the Betsiboka River Delta in Madagascar. It is one of the most visually striking river deltas in the world, especially when viewed from space.

The Betsiboka River is the largest river in Madagascar by discharge, and its delta is equally significant. The river flows into Bombetoka Bay, which further leads to the Mozambique Channel.

One of the most notable characteristics of the Betsiboka River Delta is its bright color when viewed from space.

“In this case, the color is caused by the transport of iron-rich sediment. The sediment can clog waterways in the delta’s estuarine environment, but it can also form new islands that become colonized by mangroves. Many other water bodies, such as the reservoir fed by the Jacui River in southern Brazil, are colored by reddish sediment,” said NASA.

“Despite their rusty color, these arteries of water are important for biodiversity. Algae and other microorganisms serve as a vital food source for vulnerable bird species, such as the Andean flamingo in the Laguna Colorada. Within the Betisboka River Delta, the estuary provides food, such as seagrasses, to the endangered green turtle and vulnerable dugong, or sea cow.”

The photo was captured by an astronaut on the space station on September 30, 2023.

Image Credit: NASA Earth Observatory 

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