PORTSMOUTH, Va. (USA TODAY) -- A 40-foot whale that's been swimming around in the Elizabeth River since last week has died.
Joan Barns of the Virginia Aquarium & Marine Science Center says the whale died on Thursday morning. A necropsy is planned, and tissue and blood samples have been taken for further study.
Virginia Marine Police were out with the Virginia Aquarium's Stranding Response Team Thursday to monitor the status of the whale at the St. Julien's Creek Annex in Portsmouth.
The Stranding Team was trying to tow the nearly 40,000-pound mammal to a facility at Craney Island where a necropsy will be performed Friday morning.
The 35- to 45-foot sei whale was first spotted Monday in the river's Southern Branch near the Jordan Bridge and Paradise Creek.
The National Oceanic and Atmospheric Administration says sei whales are usually seen in deeper waters of oceanic areas far from the coastline.
On Wednesday,the whale was stuck on the bottom of the creek near the bridge; officials were hoping it would free itself at high tide and be able to swim to deeper water.
The whale was first spotted Aug. 14 in the James River between the Hampton Roads Bridge-Tunnel and the Monitor-Merrimac Memorial Bridge-Tunnel and didn't seem to be in any distress, officials said.
Contributing: The Associated Press
PHOTOS: Majestic whale pictures