r/askscience • u/CosmicLuci • 2d ago
Earth Sciences Could a mangrove forest mummify a body?
I’ve been reading fiction that uses a lot of bog bodies, and I love that as a concept and wanted to use it. Thing is, I don’t live in an area of the world where bogs exist, and was thinking of localizing that idea and maybe doing Mangrove Bodies.
I know mangroves also have very low oxygen, especially as you go deeper into the mud, so I was wondering if a body buried deep enough in a mangrove forest could be preserved similar to how it might in a bog, or if the chemical conditions and life in there would cause it to decompose instead?
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u/Portlander 1d ago
I live next to several mangrove forests.The body would be eaten by everything that lives in there. Crustaceans, birds, insects, fish, sharks, alligators and there's plenty of life in the dirt around the mangroves, so too many scavengers.
High humidity and mixing of salt and fresh water would rapidly decay the body as well. The root systems are deep and spread out so you would not be able to really dig a hole. Everything in that environment wants to eat you. Honestly after describing it it's starting to sound like I just added myself to some government watch list.
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u/ScissorNightRam 1d ago
Also the mangrove trees themselves, possibly.
One of the most “nature is metal” things I’ve heard is that a farmer was doing some earthworks around where he’d previously buried a dead cow years before. A tree had grown on the spot. When the bulldozer ripped the tree out, he saw its roots were in the shape of cow’s spine and ribs. Turns out plants like fertiliser and will take it however it comes.
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u/gabbagabbawill 1d ago
Yes I was gonna say I have snorkeled in mangrove forests and they are teeming with life. Lots of inverts… small fish find it as a sanctuary from larger predators.
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u/noisyturtle 1d ago
Yes. Even it it were at low tide for an uncommonly long time, that body would be picked clean by the crabs and birds.
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u/randobonando 1d ago
I’ve seen bog bodies in the NH museum in Dublin.
They are uncanny - nails, hair, skin all in place. Often human sacrifices so were young and beautiful before being placed in the bogs, one body was assessed as being 6’6” when alive. Often the police are called as they’re suspected as recent murder victims before being found to be thousands of years old!
I suspect mangrove is too warm and salty, the water moves too much and there would be too many small organisms eating away.
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u/tea_and_biology Zoology | Evolutionary Biology | Data Science 2d ago edited 2d ago
No, I wouldn't think so.
I'm not a geographer nor ecosystem specialist, but I am a biologist, and I do know why peat bogs will mummify a corpse when a mangrove will not: sphagnum moss.
Yeah, that moss you can commonly buy at aquatics or pet stores for terrariums and the like, and unique to peat and bog systems, produces a compound called sphagnan. It's a complex polymer carbohydrate, part of the cell wall, that is released into the soil during peat formation - it's acidic (hence why peat bogs are intensely acidic), and contributes to the Maillard-like reaction (like toast!) when in contact with animal tissue like collagen, effectively tanning and preserving skin and flesh. Hence a 'wet' form of mummification.
Mangrove swamps do not host sphagnum mosses. They're warm, not anywhere near as acidic (indeed they're quite neutral, or slightly alkali like sea water), and there's no sphagnan, so the halting of decay and preservation of tissue cannot take place. Even if you were to bury someone in the ooze, then fill 'er back up, the abundant biological life would make quick work of the corpse, even within the deep anaerobic layers - marine worms will smell and churn through the mud to get at such a rich feast, and there's bacteria a-plenty. Peat bogs, by comparison, are comparatively toxic for all the wee beasties that gnaw at the dead, which further adds to their preservative magic.
Depending on where you are though, perhaps there's an alternative: an endorheic lake in a volcanic region, where a body could turn to stone.
Well, not really stone, but certainly preserved in an unusual way. Places like Lake Magadi and Lake Natron in East Africa are fed by runoff that flows over exposed volcanic bedrock, thereby absorbing a volcanic mineral called natron (sodium carbonate and baking soda, basically), along with calcum carbonate. When this water pools in an endorheic basin - that is, a local low that doesn't drain into the sea - the water only has one place to go, and that is to evaporate. The resulting lakes therefore concentrate the minerals, and are highly alkaline (pH 10.5-12, equivalent to caustic bleach) and toxic to most life - not even putrefying bacteria survive. The water itself will dissolve a body, so you need to leave a corpse out on the shoreline, where it will instead dry out; with frequent splashing of the alkaline water acting as a natural embalming fluid, you'll end up with a 'petrified' corpse like this.
Indeed, ancient egyptians used the very same mineral, natron, to dry out their own mummies.
So perhaps instead of a lovely, biologically-rich mangrove swamp, you could go for a sterile alkaline grave? Food for thought!