1.8m (5.9 foot) juvenile female long-beaked common dolphin, a species not
usually seen north of central California, was found dead in Little Skookum Inlet
near Shelton, WA on the afternoon of 28 March. The animal was picked up by
Cascadia Research (CRC) personnel and transported to Washington Department of
Fish and Wildlife (WDFW) in Lakewood where a detailed examination was performed
by biologists from CRC and WDFW the same day.
animal was in good body and good post mortem condition, allowing for a very
thorough external and internal examination. The skin appeared to be abnormal in
texture over roughly 50% of the body; with some places of algal or diatom growth
on the surface of the skin, and numerous small parasites that had penetrated
into the blubber and to the surface of the muscle layer. There were a number of
healed teeth marks from other small cetaceans (species unknown). There were no
signs of recent trauma or entanglement.
examination revealed abnormalities in the thoracic cavity, including dark
congested lungs with portions that appeared unable to function. We suspect these
abnormalities played a significant role in cause of mortality, but the specific
cause of death will not be determined until samples have been processed. A
number of other samples were collected for genetics, biotoxin, food habit, and
contaminant analyses and will be processed during the coming weeks and months.
The skeleton has been retained for preservation and educational/scientific use.
Dolphins are not typically found in the Puget Sound; however, at least two
different individual long-beaked common dolphins were sighted and photographed
in June 2011 off Burfoot Park in Olympia (see http://www.cascadiaresearch.org/commondolphin2011.htm
for info and photographs). Additional sightings were frequent in south Sound
during the summer months and occasional throughout the fall and winter, with the
most recent sighting on 25 March in Eld Inlet. Photographs from the Eld Inlet
sighting are distant so we cannot be certain, but the animal appears to have
similar pigmentation to the stranded dolphin. Photographs of the stranded
dolphin were compared to the two identified individuals from 2011; it has been
determined that the stranded dolphin is a different individual.
stranding of this dolphin represents the third unusual species of whale and
dolphin to be sighted and subsequently found dead in southern Puget Sound in
recent years. Since 2010, two Bryde's whales and two bottlenose dolphins were
sighted in southern Puget Sound prior to stranding; all are warm water species
not generally known to occur this far north. While these sightings and
strandings suggest a troubling pattern and appear to be related, they thus far
have only involved small numbers of animals and it is unclear how these
strandings relate to changing ocean conditions.
The presence of other common dolphins in the region at this time is unknown—any sightings, photographs, or video of these or other cetaceans are greatly appreciated. Please report any porpoise, dolphin, or whale sightings to Cascadia Research at 360-943-7325.