Crawfish Shells as Compost

[bavila]

Hey y'all,

Getting ready for our annual boil in the midst of lots of spring gardening, which has me wondering, wouldn't those leftover shells make excellent compost? Anyone do this? Any tips? My dad seems to think I'd need to rinse them out, but that doesn't seem necessary to me.

Thanks!

[Kouign Aman]

They'll rot, but they will stink to high heaven for a couple/few weeks first.

How badly do you hate your neighbors?

Maybe someone knows if covering them with soil will control the smell?

Rinse - if they are covered in salt (like old bay seasoning or something), you would want to rinse that off, but otherwise, I cant see why you'd rinse.

[HungryC]

I wouldn't recommend it, for reasons aside from the obvious smell. Crawfish shells (really, any arthropod exoskeletons) are mostly chitin, a polysaccharide that doesn't break down as easily as the cellulose compounds in plants (which are also polysaccharides, but not nearly as strongly bonded or as long-chain as chitin). Chitin is decomposed by the action of certain bacteria, which aren't the usual suspects found in your ordinary compost heap. Think about those creepy cicada husks lurking in your garden: those things persist for months and months after they're discarded. They're made of chitin, too.

I remember reading about a few research attempts in the late 80s-early 90s to use crawfish & shrimp trash as a source of chitin used in industrial applications, but the cleaning of residual bio-debris from the shells proved to be tricky.

If you do try it, make sure you pH test the resulting compost before you spread it. It may end up too high in nitrogen (basic) to use "straight" without burning/killing your plants.

[tim]

Hi,

I'd suggest crayfish butter.

Tim

[bavila]

Well, I found this interview from NPR/Living on Earth regarding a seafood company in Maine that had started a compost business of sorts. Seems the chitin was actually desirable as a bug repellant (not sure what bugs yet), and it was mixed with sawdust for a carbon source to balance the nitrogen. Maybe I'll just need a good carbon source to mix in -- good thing I've got at least a dozen mature trees on my property and a pile of leaves still hanging around from the fall.

To avoid the stink, I think my friend's mom has just buried the shells so they weren't exposed to open air. Not sure how that worked out for her. I'd definitely need to keep them away from the kids.

Will keep you all abreast of my findings...

[HungryC]

So if you bury the shells, how do you turn/aerate the compost? Or do you just let it sit for a long, long time? I'm a hardcore composter, but I don't think my neighbors would stand for crawfish composting! I'd be run out of my 'hood for sure. Shredded newspaper might be a good substitute for sawdust or leaves, too.

[hummingbirdkiss]

two words where I live for not putting any shellfish in my compost

rats and raccoons!!! they will get into there and feast away!!!

[budrichard]

Raccoons. big time! We had a small farm at one time and every time i put Maine lobster shells in the trash, the 'coons would just destroy the trash to get to the shells. We put the trash in garage and kept the door closed but we always found the trash destroyed. We initially thought that it was due to an oversight by one of us until I came home late one night and observed a 'coon lifting the door open with a paw to crawl under and get to the trash! -Dick

[Magictofu]

Why not just make a bisque instead?