orca

Climate Spotlight: Orca

Featured image from: https://www.afsc.noaa.gov/Quarterly/amj2005/divrptsNMML3.htm, by Robert Pitman (NOAA)

The Orca, commonly known as the Killer Whale, is not actually a whale, but the largest species of dolphin.  Weighing up to 6 tons, Killer Whales are one of the world’s most powerful predators and can be identified by their distinctive black and white coloration.

Killer whales are known to hunt in pods of up to 40 individuals. Each pod has a distinct call and hunting technique. Individuals can recognize the specific calls made by other members of their pod and pass it down from generation to generation, creating a unique dialect only known to the members of that pod. Killer whales primarily rely on echolocation to communicate when hunting and navigating in dark waters but unfortunately, noise pollution from human activity is negatively interfering with their ability to communicate.

Although Killer Whales are known to feed on a wide variety of prey, including fish, seals, and other marine mammals, not all Killer Whales rely on the same resources. Killer Whales can therefore be divided into subspecies based on what they eat. One subspecies feeds primarily on fish living under the Antarctic ice sheets and has been known to remain in Antarctic waters because of a reliable food supply. Rising water temperatures are melting Antarctic ice, destroying the Killer Whales’ habitat as well as their food supply. It is not known if Antarctic killer whales will be able to adapt to these rapid changes or if climate change will lead to the extinction of this subspecies. In comparison, populations of Killer Whales in the Pacific Northwest feed primarily on salmon. This subspecies is on the endangered species list because salmon populations are declining due to overfishing, disease and warmer ocean temperatures.

This image shows the range in which Killer Whales live, however, orcas are divided into subspecies based on both the location where they are found and their preferred food source.
The above image shows the range in which orcas live; orcas are divided into subspecies based on both the location where they are found and their preferred food source. Image from: http://www.nmfs.noaa.gov/pr/species/mammals/whales/killer-whale.html

This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

To learn more about orcas visit these links:

http://www.nmfs.noaa.gov/pr/species/mammals/whales/killer-whale.html#description  

http://www.takepart.com/article/2016/02/02/ship-noise-may-harm-worlds-most-endangered-orcas/

https://www.nationalgeographic.com/animals/mammals/o/orca/

Script Authors: Marie Defretin and Mariana Gonzalez

Contributing professor: Dr. Lisa Campbell

Editor: James M. Fiorendino