Abstract

An adult humpback whale swam into shallow water and was stranded one October evening, when the tide went out of the San Francisco Bay. His body was entirely exposed twice, as it took almost 24 hours and two tide cycles to organize the equipment to pull him to freedom.

Discussion

An adult male humpback whale was stranded on a mud flat amongst numerous rocks, and was kept moist using portable pumps and a fire hose until the tide came back in. To determine if his health was a reason for stranding, blood was taken from a small vein just inside his mouth. CBC and blood chemistries were performed at a local hospital. The blood parameters were within the normal range of other species of whales with known normal blood parameters.

The whale was stranded with his head facing into a shallow semi-circle of rocks. The only way to move him to deeper water was to push him or pull him straight backwards. An unsuccessful attempt was made to leverage the whale out with the first high tide at 4 AM. Twelve foot long pieces of lumber were placed under the lower jaw of the whale in an effort to push him to deeper water, but the animal was too large to move in this manner. The whale was kept wet again using the pumps and fire hose when the low tide left him exposed a second time. With the next high tide, the whale was moved successfully. His tail was dangerous and inaccessible, as it was resting in a deeper pool of water, and was submerged most of the time. Therefore the only method to pull him backwards was to place a net around the front of his head and pull him straight back. A 15 x 15 foot cargo net made of 1.5 inch nylon webbing was placed around the head of the whale. The net had been rigged with a 1 inch diameter soft nylon rope attached to steel eyes on each corner of the cargo net. The net was laid flat in the water, and one half was bunched under the lower jaw of the whale. The other half was brought up over the upper jaw of the whale, and the nylon lines were pulled back on each side of the whale and attached to a 41 foot Coast Guard cutter. The slack was taken up, and the cutter pulled the whale backwards off the mud and rock area where he was stranded. As the whale was pulled into deeper water, his body began to swing to one side, causing the cargo net and tow ropes to fall free of his head. The whale swam free, and traveled 100 yards only to strand again on a sand bar. The cargo net method was used again to move the whale out to deeper water. This time he began to swim, and was escorted out into the middle of the San Francisco Bay by a small flotilla of pipe-banging inflatable craft. He returned uneventfully to the ocean the next day.