Featured Research

from universities, journals, and other organizations

Stranded orcas hold critical clues for scientists

Date:
June 7, 2013
Source:
University of California - Davis
Summary:
The development of a standardized killer-whale necropsy system has boosted the complete data from killer-whale strandings from two percent to about 33 percent, according to a recent study.

This killer whale was stranded in California in 2005. Increased necropsies on stranded killer whales are helping scientists learn more about the species.
Credit: Jeff Jacobsen/Humboldt State University

The development of a standardized killer-whale necropsy system has boosted the collection of complete data from killer-whale strandings from 2 percent to about 33 percent, according to a recent study from a team of scientists, including a University of California, Davis wildlife veterinarian.

The study, published recently in the journal Marine Mammal Science, suggests that the data can help scientists better understand the life history of the orca species.

The killer-whale necropsy system was co-developed by Joe Gaydos, director of the SeaDoc Society -- a program of the UC Davis Wildlife Health Center within the School of Veterinary Medicine -- and Stephen Raverty, veterinary pathologist with the British Columbia Ministry of Agriculture.

"Because killer whales are apex predators and flagship conservation species, strandings are sad events," said Gaydos. "But this study confirms that if we make every effort to understand why the strandings occurred, we will ultimately improve the fate of the species."

Gaydos and Raverty developed the standardized killer-whale necropsy system in 2004. The analysis of strandings since then has shown that the protocol, along with increased funding for southern resident killer-whale recovery, has increased the collection of complete data from killer-whale strandings. Traditionally, only one in 50 stranded whale cadavers would be analyzed; now one in three get a full examination.

The increased recovery funding was provided by the U.S. National Marine Fisheries Service and Canadian Department of Fisheries and Oceans.

For the study, researchers analyzed North Pacific killer-whale strandings dating back to 1925. The report noted that while orcas are some of the most widely distributed whales on Earth, very few dead ones are ever found. Over the last two decades, an average of just 10 a year have been discovered stranded across the entire North Pacific Ocean.

"Each stranded orca should be viewed as a unique opportunity to enhance our understanding of this magnificent species," said co-author Raverty.

The study found that 88 percent of all reported killer-whale strandings are fatal, while only 12 percent of the stranded killer whales make it off the beach alive. The dead whales can provide critical clues to the species' overall life history, genetics, and health, as well as the causes of death. With such limited opportunity to do comprehensive sampling and studies, the authors noted the disturbing fact that, until recently, less than 2 percent of dead killer whales were thoroughly examined.

While the study was designed to look at stranding trends and did not evaluate the causes, necropsies on beached orcas have shown that they absorb extremely high loads of humanmade toxins, suffer from infectious diseases and, in the case of fish-eating populations, depend primarily on severely depleted salmon stocks. With the standardized protocol now in place -- providing much more complete data on strandings -- researchers are getting a clearer picture of killer-whale life and death.

"This was a herculean effort to learn more about one of the ocean's top predators," said lead author Michelle Barbieri, a former SeaDoc Society scientist and UC Davis graduate who is currently the lead veterinarian for the National Oceanic and Atmospheric Administration's Hawaiian Monk Seal Research Program.

"We could not have done this without the collaboration of dozens of killer-whale scientists from around the world, who provided stranding and population data from Washington, Oregon, California, Alaska, Hawaii, British Columbia, Mexico, Japan and Russia," she said.


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michelle M. Barbieri, Stephen Raverty, M. Bradley Hanson, Stephanie Venn-Watson, John K. B. Ford, Joseph K. Gaydos. Spatial and temporal analysis of killer whale (Orcinus orca) strandings in the North Pacific Ocean and the benefits of a coordinated stranding response protocol. Marine Mammal Science, 2013; DOI: 10.1111/mms.12044

Cite This Page:

University of California - Davis. "Stranded orcas hold critical clues for scientists." ScienceDaily. ScienceDaily, 7 June 2013. <www.sciencedaily.com/releases/2013/06/130607131012.htm>.
University of California - Davis. (2013, June 7). Stranded orcas hold critical clues for scientists. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2013/06/130607131012.htm
University of California - Davis. "Stranded orcas hold critical clues for scientists." ScienceDaily. www.sciencedaily.com/releases/2013/06/130607131012.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Adorable Video of Baby Rhino and Lamb Friend Playing

Adorable Video of Baby Rhino and Lamb Friend Playing

Buzz60 (Oct. 20, 2014) Gertjie the Rhino and Lammie the Lamb are teaching the world about animal conservation and friendship. TC Newman (@PurpleTCNewman) has the adorable video! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins