Another bottlenose dolphin has been identified from the group that first appeared in the Puget Sound in September, 2017. A single dolphin was observed on March 9, 2018 in Central Puget Sound off Tacoma, where several people sent in sighting reports and pictures to Orca Network, who forwarded them to Cascadia Research. As with the previous sighting, Cascadia Research sent the images to our collaborators in California Golden Gate Cetacean Research and Okeanis, where they were able to match the images to a well known mature female known as “Stump” (Catalog IDs: GGCR SFB T 03, MB 79, and CDOC 33020). Just as with the first dolphin we identified, known as Miss, Stump was first photographed by researchers in the early-1980s and was also an early explorer as the stock expanded northward. Stump and Miss were known to hang out together at times down in California, so it is not too surprising that they should end up in the Puget Sound together.
We would specifically like to thank Wayne Lattuca for providing pictures that we were able to use for this photo-ID effort.
If you look at the shape and position of the nicks and notches on the trailing edge of the dorsal fin in the two photos below, you can see how they line up, even though the images are from opposite sides.
Fin shapes can change as dolphins age, new injuries add nicks over time. You might have noticed that the leading edge at the top of the fin appears to have a different curve to it in the California and Washington pictures. One of the pictures that Wayne Lattuca sent shows that Stump’s dorsal fin has a bend towards her right side. This bend may be new, or it may have increased over the last two years, changing the curve of the leading edge as seen from the side. Dorsal fins with varying degrees of bend are known to occur in this population.
With the knowledge that Stump is one of the other dolphins in the Puget Sound, we went back and reviewed previous images. While they were not good enough to use for photo-ID, sometimes they have enough detail to match to an animal that is known to be in the area. One of the photographs from the Island Adventures encounter that led to the identification of Miss, had a second dolphin in it. It has just enough detail that we can be fairly certain that the second dolphin is stump.
See the earlier post for more information on the California coastal bottlenose stock, and their northward range expansion.
We are still looking for sighting reports and photographs
If you see bottlenose or other species of dolphins anywhere in Washington State, we would like to hear about it. Call in your reports to Cascadia Research at (360) 943-7325, or email danderson@cascadiaresearch.org.