Saturday, October 18, 2008

Salt and Slaves

Prior to refrigeration, salt was a hot commodity and often hard to come by. Bonaire was an important supplier of salt for centuries while its neighbor, Curacao, was a major slave trade center. Salt from Bonaire had a lot of ties to slavery. Slave labor was used to produce huge salt ponds for solar-salt production and to harvest the salt. It's also quite likely that many slaves from Africa that ended up on the island were purchased using salt (African tribes were often involved in capturing other Africans to sell into slavery, sometimes they were sold for salt. Apparently, the word salary comes from payment in salt.). Slave huts from this time still exist on Bonaire and two dive sites, White Slave (pictured here as I entered the water) and Red Slave, are named for the obelisks on the shore that signaled where boats could pick up their salt load.
With the abolishment of slavery in 1863, the salt mining here ended for about a century. When solar salt production returned to the island, heavy machinery, conveyer belts and large piers were employed to produce the salt.

The salt pier that was constructed provides an eerie dive site; its pillars provide vertical substrate for encrusting organisms, like these sponges (do you see the fish hiding in this picture?).

Many fish, like these schoolmaster snappers, also hang out under the pier and near the pillars (these guys are waiting for evening to hunt). Just the other side of the road from the pier are huge mountains of salt. Just looking at these mountains makes my blood pressure skyrocket. The salt is loaded on a conveyor belt near these mountains and it is carried above the road, down the peir and dumped onto cargo ships. Much of the salt is never consumed, but it ends up in water softeners and on our roads in the winter.
The salt ponds used to produce these huge mountains typically have a pink or brown color. In the picture below from and my picture above, you can see the color of the ponds. Why are the ponds pink? Sea water isn't pink. Think about your microbiology. Not many things can live in such hypersaline environments.....ya know, they'd have to be really halophilic (latin: halo=salt or "the sea" and philic = love). Really, they'd have to be extreme halophiles. Yeah. They are. Prokaryotes in the group archaea (organisms formerly known as types of bacteria) live in these ponds and their pigments used in photosynthesis color the water. You can go archaea watching closer to home. They're often seen in hotsprings (extreme thermophiles) and salt lakes. Other species live in your intestines.

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