Grampus Dolphin Washes Ashore as Rare British Columbia Visitor

Summary: A dead female Grampus dolphin washes ashore Saturday, Feb. 20, on the Haida Gwaii archipelago's Graham Island as a rare British Columbia visitor.

Vancouver Aquarium researcher Caitlin Birdsall (left) heads necropsy of a rare Risso's dolphin that washed onto the shore of Haida Gwaii Saturday, Feb.20, 2016: Vancouver Aquarium @vanaqua via Twitter Feb. 25, 2016

Two local residents of northern coastal British Columbia’s Haida Gwaii archipelago discovered a dead female Grampus dolphin, about 11 feet (3.3 meters) long, Saturday, Feb. 20, 2016, on a beach near the hamlet of Tlell on Graham Island’s east central coast.

Researchers from the Vancouver Aquarium, the aquarium’s B.C. Cetacean Sightings Network and Canada’s Department of Fisheries and Oceans conducted a necropsy, or autopsy of an animal, two days later, Monday, Feb. 22. A cause of death was not determined.

“So today we did some sampling from a female Risso’s dolphin that had washed ashore near Tlell, Haida Gwaii. So we took some samples from a variety of organs. We tried to collect some fluid. And these types of samples can tell us a lot of information. We didn’t find anything conclusive right away, but luckily we can send this to pathologists and they’ll be able to take a closer look at the tissue samples and hopefully figure out how this Risso’s dolphin came to be here today,” Tessa Danelesko, coordinator for the Vancouver Aquarium’s B.C. Cetacean Sightings Network, says in a video produced Monday, Feb. 22, by the Vancouver Aquarium Marine Science Centre.

The wide range North American range for Grampus dolphins reaches as far north as the Atlantic Ocean’s Gulf of Alaska and the Pacific Ocean’s Labrador Straits. Grampus dolphins, however, are rarely seen along Canada’s oceanic coasts.

Grampus dolphins (Grampus griseus) inhabit temperate and tropical oceans worldwide. They favor offshore habitats along seamounts and submarine canyons and near the edge of steep slopes.

Grampus dolphins tend to feed at night and travel during the day. They engage in surface acrobatics, such as breaching, skyhopping, surfing and swimming in ship wakes.

Grampus dolphin young feature a white belly amidst otherwise uniform greyness. Juveniles display chocolate brown- or olive-colored backs. Greyness returns with adulthood.

Cases of mistaken identity occur in their associations with other cetacean species, especially bottlenose dolphins and pilot whales. A Grampus dolphin’s beakless, bluntly shaped head, with a bulbous forehead, encourages confusion with pilot whales. Also, a Grampus dolphin’s tall dorsal fin leads to confusion with bottlenose dolphins or female and juvenile killer whales.

Scars from biting by other Risso’s dolphins and from squid as their major prey give each Grampus dolphin an intricately unique patterning of white scars that often hides the body’s basic grey coloring. A Grampus dolphin also is the only species of cetaceans with a distinctive vertical crease that runs from forehead to smiling mouth.

Major challenges include accidental entanglement in fishing equipment, climate change and noise pollution. Grampus dolphin hunts occurs around the Faroe Islands in the Atlantic Ocean. Pacific Ocean hunts are undertaken near Japan, the Philippines, Sri Lanka and Taiwan.

A global population estimate does not exist for Grampus dolphins. The Red List of Threatened Species maintained by the International Union for Conservation of Nature and Natural Resources (IUCN) assigns the species to the least concern (LC) status.

Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has included the Grampus dolphin in the CMS species list since 1988. In effect since 1983, the Convention, known also as the Bonn Convention, aims for conservation of avian, marine and terrestrial migratory species throughout their ranges. Appendix I lists threatened migratory species.

Appendix II identifies migratory species needing or significantly benefiting from international cooperation and encourages the framing of global and regional conservation agreements. Agreements formed under the Convention’s auspices that list the Grampus dolphin include the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS), in effect since 2001, and the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS), in effect since 1994.

As an all-inclusive statute, the Marine Mammal Protection Act of 1972 (MMPA) offers protection to all marine mammals within United States’ waters.

closeup of unique scarring pattern on Grampus dolphin offshore of Avila Beach, San Luis Obispo County, Central California: “Mike” Michael L. Baird, CC BY 2.0, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Vancouver Aquarium researcher Caitlin Birdsall (left) heads necropsy of a rare Risso's dolphin that washed onto the shore of Haida Gwaii Saturday, Feb.20, 2016: Vancouver Aquarium‏ @vanaqua via Twitter Feb. 25, 2016, @ https://twitter.com/vanaqua/status/702952518574276608

Grampus dolphin offshore of Avila Beach, San Luis Obispo County, Central California: "Mike" Michael L. Baird, CC BY 2.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Risso%27s_dolphin.jpg

For further information:

The Canadian Press. "Another rare animal washes up on a cold B.C. beach (with video)." Vancouver Sun. Feb. 23, 2016.
Available @ http://www.vancouversun.com/technology/Another+rare+animal+washes+cold+beach/11741660/story.html

CMS COP12 Newsroom. "Appendix I & II of CMS." CMS Convention on the Conservation of Migratory Species of Wild Animals > Species.
Available @ http://www.cms.int/en/page/appendix-i-ii-cms

Nuno D.S.G. Pereira, José. "Field Notes on Risso's Dolphin (Grampus griseus) Distribution, Social Ecology, Behaviour, and Occurrence in the Azores."Aquatic Mammals, vol. 34, issue 4 (2008): 426-435. DOI: 10.1578/AM.34.4.2008.426
Available @ https://www.researchgate.net/publication/228620754_Field_notes_on_Risso%27s_dolphin_Grampus_griseus_distribution_social_ecology_behaviour_and_occurrence_in_the_Azores

"Rare dolphin washes up in Haida Gwaii." CBC News > Canada > British Columbia. Feb. 24, 2016.
Available @ http://www.cbc.ca/news/canada/british-columbia/rare-dolphin-washes-up-in-haida-gwaii-1.3462720?

Vancouver Aquarium‏ @vanaqua. "Researchers find third animal rarely seen in waters off BC on an island beach." Twitter. Feb. 25, 2016.
Available @ https://twitter.com/vanaqua/status/702952518574276608