This Alkaline African Lake Turns Animals into Stone

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In 2011, when he was traveling to shoot photos for a new book on the disappearing wildlife of East Africa, Across the Ravaged Land, photographer Nick Brandt came across a truly astounding place: A natural lake that seemingly turns all sorts of animals into stone.

The ghastly Lake Natron, in northern Tanzania, is a salt lake—meaning that water flows in, but doesn’t flow out, so it can only escape by evaporation. Over time, as water evaporates, it leaves behind high concentrations of salt and other minerals, like at the Dead Sea and Utah’s Great Salt Lake.

Unlike those other lakes, though, Lake Natron is extremely alkaline, due to high amounts of the chemical natron (a mix of sodium carbonate and baking soda) in the water. The water’s pH has been measured as high as 10.5—nearly as high as ammonia. “It’s so high that it would strip the ink off my Kodak film boxes within a few seconds,” Brandt says.

Written By: Joseph Stromberg
continue to source article at blogs.smithsonianmag.com

11 COMMENTS

  1. Lake Natron is a prime flamingo habitat.

    http://en.wikipedia.org/wiki/Lake-Natron

    The high temperature (up to 60°C) and the high and very variable salt content of the lake does not support wildlife. However it is an important habitat for flamingos and is home to endemic algae, invertebrates and round the margins even fish that can survive in the slightly less salty water.

    The lake is the only regular breeding area in East Africa for the 2.5 million Lesser Flamingoes, whose status of “near threatened” is a consequence of their dependence on the single breeding location. As salinity increases, so do the number of cyanobacteria, and the lake can support more nests. These flamingoes, the single large flock in East Africa, gather along saline lakes in the region, where they feed on Spirulina (a blue-green algae with red pigments). Lake Natron is a safe breeding location because its caustic environment is a barrier against predators trying to reach their nests on seasonally-forming evaporite islands. Greater Flamingo also breed on the mud flats.

    The color of the lake is characteristic of those where very high evaporation rates occur. As water evaporates during the dry season, salinity levels increase to the point that salt-loving microorganisms begin to thrive. Such halophile organisms include some cyanobacteria that make their own food with photosynthesis as plants do. The red accessory photosynthesizing pigment in the cyanobacteria produces the deep reds of the open water of the lake, and orange colors of the shallow parts of the lake. The alkali salt crust on the surface of the lake is also often colored red or pink by the salt-loving microorganisms that live there.

    The colours from the micro-organisms also colours the flamingo feathers.

    crookedshoes @1 – And, one species of fish lives there? Let’s revisit in 1000 years and see if there are two.

    The fish beat you to it!

    Even more amazing than the ability of the flamingoes to live in these conditions is the fact that two endemic fish species, the alkaline tilapias (Alcolapia latilabris and A. ndalalani; A. alcalica is also present in the lake, but not endemic), thrive in the waters at the edges of the hot spring inlets.

    • In reply to #7 by Dublin-atheist:

      The creationists will probably use this phenomenon to explain how dinosaur fossils can less than 6000 years old.

      Ken Ham is out there right now, dredging the lake for Lot’s wife.

  2. Another report from the trenches….. this article will be on my students’ iPads tomorrow morning (yes, every student in my school has been issued an iPad). We will be using it as an opener to class. The lesson tomorrow is the dissociation of water. You guessed it…..pH (and since it is biology, the actions of buffers)…. I am very very excited to see the kids faces as they process these pictures and I am even more excited to field the torrent of questions that will result….

    This is awesome!

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