Monday, May 17, 2010

Boiling the Hooded Seal Bones

Eliza and her seal
Wow, what an exhausting weekend.  I spent two full days helping Eliza Brandy cut, boil, and threaten the meat off the hooded seal skeleton.  It was a lot of fun and I learned all kinds of weird and wonderful things about seal anatomy, but it was a very big job.  Despite the cool temperatures and drizzly weather, we had a small army of volunteers help out on Saturday and Lori came by for the full day on Sunday.

A bloody good time!
At the start of Saturday morning, the seal carcass was stored in sections in four big rubbermaid tubs.  The skin was off everything (except the skull and flippers) and the organs were removed, but all the meat and bones were still there.

Soaking the bones
By Sunday evening all the meat was boiled off the bones, with the exception of one or two of the flippers, and the boiled bones were sitting in the lab in detergent solutions for the next stage in the cleaning and degreasing. Ultimately the bones will be clean and white and part of the faunal collection in the Archaeology Department at Memorial University, with the exception of the skull which is going to the Biology Department and a few of the teeth which are going back to the Department of Fisheries and Ocean's to help age the animal.

A boiled femur - they're tiny!
Saturday was a pretty bloody day.  The meat had a very odd consistency.  It didn't really hold together the way beef or chicken does, you could pull it apart with your fingers.  It was like short fibres packed together, maybe a little like an artificial fire log, but wet.  One of the students, Andrew, said it reminded him of fibreglass putty.  After the meat was boiled, it turned a rich brown colour and acted a lot like clay.  You could smoosh it and smear it around with your fingers like greasy mud.  Maybe that's why Amy, who studies ceramics, was so good at cleaning around all the nooks and crannies on the vertebrae.

Hooded seal eyeball - they're huge!
Sorry the pictures are so graphic, but there were some really interesting anatomical details that I think are worth sharing.  The seal's eyes for example, were huge.  Each one was the size of a jelly-filled billiard ball.  Beneath the webbed skin, the front flipper was a lot like a human limb, with short 'arm' bones and very long, flat finger bones.
Hind flipper - a foot evolved into a paddle
But the hind flippers were pretty extraordinary, with tiny short femurs, the size of a bow-tie, and long spidery toes. The most interesting thing about the hind flipper was that the outside toes were about twice the length of the middle toe, making two powerful V-shaped paddles.  In the photo on the left, you can see the five sharp little toe-nails at the end of each digit.

Distal phalange and nail
Cleaned up, those toe bones were pretty weird looking too.  Compared to other animals, all of the limb bones were flattened and the last phalange of each finger and toe have complex little cones to hold the long sharp claws.  With enough boiling the claws came loose and slid off the bone. 
By Saturday evening we had the bulk of the meat removed and all of the bones had at least started to boil.   Sunday was a much cleaner day because we were dealing with cooked meat and gristle, not blood and skin and tendons.  We started the pots boiling in the morning and spent a couple hours working on the sealskin, which I'll talk about in more detail next time.

It looks so tidy in a picture


The goal on Sunday was to get every bone this clean
Ultimately, the skeleton will end up here.
This was a huge job, and its still not really over yet.  Eliza has a bit more boiling to do on one or two flippers and there will still be a few weeks of soaking to get rid of the final bits of tissue and grease still on the bones.  Maybe I can get her to describe the process when its all done. I'll try and get some more photos when everything is finally finished and stored with the rest of MUN's Archaeology bone collection.

Cheeky gull with something from the seal
Postscript:
We were greeted almost immediately by a gull on Sunday morning.  He had one bad leg and a pretty brazen attitude.  He wound up grabbing something out of one of the bags and took off with it.  We didn't see which bag he raided - so it could have been a rib or a piece of cartilage.  If it was a rib, Eliza wanted it back, so we took off after him.  He was accosted by a group of 4 crows along the way and we hoped that the piece would be lost in the skirmish, but he held onto it.  We decided to try rushing him the next time he set it down, but that didn't work, he just picked it up again before he flew away.  He flew straight into the middle of the pond and dropped it in the water, before coming back throughout the day to see what else he could steal.

Is Eliza dejected or plotting revenge in the last photo?
 Photo Credits:
1, 3, 7-10: Tim Rast
 2: Corey Hutchings
4,6: Elaine Anton
5: Amy St John
11,12: Lori White

6 comments:

  1. It was fun snapping shots of two mainlanders in hot pursuit of a seagull hoping to retreive a stolen bone. Our gulls aren't known for their generosity, despite what NTV may try and tell you. teehee!

    ReplyDelete
  2. Aw, jerkass seagulls are no fun.

    ReplyDelete
  3. I'm really enjoying reading about the seal processing!!!

    ReplyDelete
  4. very useful info here, I am a human bone osteologist but I've been coming across strange bones on the beaches of Highlands Scotland and believe them to be seals. Just found a flipper today and have been boiling the meat off so I can identify whether I have front or rear flippers. The smell is appalling!

    ReplyDelete
  5. The hooded seal is nearly extinct

    ReplyDelete