A rotting whale carcass is sitting at Heeia Kea Boat Harbor.  Part of the harbor is closed as the more than 20-ton dead sperm whale poses a health risk.  The Department of Land and Natural Resources hired a contractor to cut up the whale and dispose of it at the Waimanalo Gulch landfill.  That should be happening this morning. The whale was first spotted Wednesday about 12 miles from Kaneohe.  Officials say the whale appears to have been dead for several weeks.  Shark warning signs are up at Kualoa Beach Park, as well, as three 6-to-8-foot sharks were spotted in the water feeding on the whale carcass.