Humpback Whale Fluke Injury of Unknown Cause

September 08, 2015 Posted by: Chris Gabriele and Janet Neilson

Photo caption: Dorsal side of whale #1083's left fluke blade. NPS photo taken under National Marine Fisheries Service scientificresearch permit #15844.Dorsal side of whale #1083’s left fluke blade. NPS photo taken under National Marine Fisheries Service research permit #15844


On June 19th 2015, Janet Neilson from the Glacier Bay Humpback Whale Monitoring Program documented a significant injury on the left fluke blade of adult male humpback whale (SEAK ID #1083) in Glacier Bay. During our previous encounter with #1083 on August 27th 2014, both of his flukes were intact. We speculate that the incision to this whale’s fluke is anthropogenic, possibly from an entanglement in line or a vessel collision. Based on the red and yellow color of the tissue around the wound, the injury appears to be recent.

After documenting #1083’s recent injury, we wondered if this whale might have been the “adult-sized” humpback whale reported on June 2nd to be entangled in commercial halibut longline gear near Willoughby Island in Glacier Bay.   During our surveys around this time, we had observed numerous humpback whales feeding near Willoughby Island, as well as numerous longline sets.  The entangled whale was described as thrashing at the surface with two orange buoys visible. A short time later, a National Park Service response team found a pair of orange buoys floating free near the island with the line frayed as if it had parted under great force. We concluded that the entangled whale had freed itself without human intervention. The next day we searched the area for entangled and/or injured whales but we did not observe anything unusual.   

Although we did not photograph #1083 in the area before the reported entanglement, he was documented very close to where the entanglement occurred on July 9th.  While the wound is not typical of an entanglement, according to scientists familiar with entanglement scarring (NOAA’s Ed Lyman and Janet Neilson), it seems possible that this brief entanglement might have produced a unique set of wounds.

We first documented whale #1083 as an adult in 1993, making him at least 23 years old this year. He is a “regular” in Glacier Bay and Icy Strait, with sightings every summer since 1993. Since June 19th, we have observed him on multiple occasions and he appears to be behaving normally. Although we may never know whether #1083’s injuries arose from entanglement, we will continue to monitor his behavior and the healing of healing of the wound.






Last updated: September 8, 2015

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