Photography

Biologists use hand-held digital cameras to obtain photos while working from research vessels

Photography is used to document the geographic variation in the morphology of dolphins in the eastern tropical Pacific. It is one of the tools used to differentiate among stocks of spotted and spinner dolphins, and between closely related species of common dolphins. Photographs substantiate the field identification of dolphin species made during shipboard abundance surveys.

Biologists use hand-held digital and 35mm cameras to obtain photographs while working from research vessels or from small inflatable boats. Photographs are often collected in conjunction with skin biopsies to distinguish differences among stocks within a species.

Dolphins

Spotted Dolphin Spotted dolphin - offshore form
Spotted dolphin - coastal form (more heavily spotted).
Long-beaked common dolphin.
Short-beaked common dolphin.

Whales and Photo-ID

Most large whales can be identified individually by variation in natural markings. For example, the black and white pattern on the underside of a humpback whale fluke is unique to each whale. Photographs of individual whales collected over time and distance can be used to determine migration patterns, population and group structure, reproductive rates, and population abundance estimates.

Photo-ID work at the SWFSC focuses on four species: Killer whales, blue whales, humpback whales, and sperm whales. Photographs collected during our surveys in the eastern tropical are particularly valuable since few other research platforms travel as far offshore. Topics being investigated include the long-range movements of killer whales and the use of the eastern tropical Pacific as a wintering ground by blue and humpback whales from separate populations of both northern and southern hemispheres. We work collaboratively with other researchers studying blue and humpback whales in the eastern Pacific, notably Cascadia Research Collective.

Whales

Blue whales are identified indvidually by the mottled pigment on the whale's side.
The black and white pattern on a humpback whale fluke is unique to each whale.
The irregularities in the trailing edge of sperm whale flukes are used as an individual identifier.
Killer whales are indentified individually by the shape of the dorsal fin and the light gray saddle patch.

Related Publications

Black, N.A., Schulman-Janiger, A., Ternullo, R.L., and M.

Guerrero-Ruiz. 1997. Killer whales of CA and western Mexico: A catalog of photo-identified individuals. NOAA Tech Memo 247.

Farley, T. 1995. Geographic variation in dorsal fin color of short-beaked common dolphins, Delphinus delphis, in the eastern Pacific Ocean. SWFSC Admin. Rep., La Jolla, LJ-95-06.

Florez-Gonzalez, L., Capelia A., J., Haase, B., Bravo, G.B, Felix, F., and T. Gerrodette. 1998. Changes in winter destinations and the northernmost record of southeastern Pacific humpback whales. Mar Mam Sci 14:189-196.

Guerrero-Ruiz, M., Gendron, D., and J. Urban R. 1998. Distribution, movements, and communities of killer whales in Gulf of CA, Mexico. Rep. Int. Whal. Commn. SC/49/SM44.

Olson, P.A., and T. Gerrodette. 2001. Photo-identification of killer whales (Orcinus orca) in the eastern tropical Pacific. 14th Biennial Conference on the Biology of Marine Mammals, Vancouver, BC, Canada, November 28 – December 3, 2001. Abstracts. The Society for Marine Mammalogy.

Last modified: 12/24/2014