Mystic Aquarium is expecting a new addition! Pearl the harbor seal is pregnant and her pup is due any day now. 

Seven-year-old Pearl has been monitored closely during the later part of her pregnancy.

“Twice a week we’re doing ultrasounds to monitor the fetal health and where the position of the fetus is, and things like that,” said Dr. Barbara Mangold, Mystic Aquarium’s associate veterinarian. 

Staff also watches for changes in her behavior.

Pearl’s trainer, Jessi Smashey, said the seal has been acting differently. “That’s to be expected due to her condition,” she said. “She has gained about 40 kilos in the time that she’s become pregnant, so as she gets larger sometimes her motivation will decrease a little bit, but that’s to be expected so everything is normal.”

40 kilos — that means Pearl has gained about 88 pounds. Pearl, who normally weighs about 120 pounds, weighed in at a whopping 206. 

Mangold said as a harbor seal gets closer to giving birth, her body temperature will start to drop. She says Pearl’s temperature has dropped slightly in recent days. 

Part of why they’re monitoring her so much — there isn’t much published about harbor seal pregnancies, so they hope this information can be useful to other aquariums in the future.

“We’re documenting everything and taking her measurements so hopefully we can publish something down the road,” said Mangold.

From what they’ve seen, they’re expecting her to give birth sometime this week. 

“She’s a really sweet animal and she gets excellent care here with our trainers.” said Mangold, “so I think it’ll be a really exiting time for us to have a little addition.”