It’s an extreme environment where little life exists beyond the native tiger species. ** LSU fans know that Death Valley is in Baton Rouge, LA. The stark images are meant to emphasize the dark effects of human activity on these ecosystems. * Nick Brandt’s book explores beyond Lake Natron and is a photographic safari across Eastern Africa featuring the region’s disappearing species. But because they thrive in this seemingly hostile environment, I’m filing them under Superphotosynthesizers here on this blog. By many accounts they have won the environmental lottery and live a pretty decadent lifestyle as far as basic photosynthetic requirements go (light, carbon dioxide, water***). So don’t be fooled into thinking that Lake Natron is really a Death Valley.** Also, I’m not sure if I would even call the cyanobacteria that live there superphotosynthesizers either. These conditions work together to create the algal blooms that give the lake its palette of red, orange and pink. Cyanobacteria have strategies for taking up both carbon dioxide and bicarbonate from their environment to ensure a steady supply to the Rubsico enzyme that can fix them into sugar. There’s so much carbon dioxide and carbonate around that it exceeds the amount of other ions in the water (calcium and magnesium) which react and precipitate out as insoluble carbonate salts. All of these carbonates are coming from the alkaline lava found in the general area of the Rift Valley. These caustic aka ‘soda lakes’ ensure that the waters there are saturated with carbon dioxide and bicarbonate. The solubility of the hydrated form of carbon dioxide (bicarbonate) is what increases in higher pH solutions. Well, for those of you sticklers out there, this isn’t entirely true either. the amount of it that can stay dissolved in the water) is greater at higher pH. Still confused? Here’s a quick chemistry refresher. The characteristic warm temperatures and abundance of direct sunlight in this shallow lake may make sense at first glance, but what about that awful pH? Haven’t we been taught that life prefers a pH closer to 7? Well, not necessarily if you are a cyanobacterium that feeds on carbon dioxide. ![]() These salt-loving superphotosynthesizers also transfer their color to the millions of lesser flamingoes that feed on them and use the lake as their nesting ground.Īs it turns out, the conditions in Lake Natron make it one of the most productive environments, photosynthetically speaking. The predominant strains include species of Spirulina, Cyanospira, Synechococcus and Chroococcus. ![]() ![]() At the producer trophic level, it supports several different species of cyanobacteria that give the lake its red color. ![]() While shallow Lake Natron is an extreme environment with a pH greater than 10 and water temperatures of more than 100 degrees Fahrenheit, it supports a thriving ecosystem. “Reanimated, alive again in death.Satellite imagery of Lake Natron with features labelled. “I took these creatures as I found them on the shoreline, and then placed them in ‘living’ positions, bringing them back to ‘life’, as it were,” Brandt said. It’s that same salt that mummifies the creatures and preserves them into the calcified, statue-like figures that Brandt stumbled upon on the edge of the lake. “So things that get caught in the lake do die because they just get covered in salt very quickly.” “If you imagine a bird getting water on its feathers it would very quickly be too heavy to fly,” said Harper. It is very, very hot, so water evaporates very quickly, leaving only the crust of salt on the animal. It’s so caustic that only one type of fish – Tilapia grahami – and certain bacteria can actually live in it.īut it’s the temperature of the air around the lake that seals the fate of these animals. But when they try to land, or even worse, fall in, they become coated with water that has an extremely high concentration of sodium carbonate, a salt-like mineral.
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