Tag Archives: Sam Wasser

Orca hormones linking pregnancies to prey will go into medical files

Hormones found in the feces of killer whales are providing unique insights about the health of Southern Resident orcas — including pregnancy status and stress levels. Fortunately, such information can be gathered with little disturbance to the animals.

Tucker, a Labrador retriever mix, has a keen ability to track down killer whale feces, which contains trace levels of hormones and toxic chemicals. // Photo: Kelley Balcomb-Bartok

The latest information about hormones will soon be incorporated into a new health-status database with individual medical reports being compiled for each whale in the Southern Resident population.

A recently published study confirms hormonally what researchers have observed for years, that when the whales’ primary food supply — chinook salmon — is plentiful, the number of newborn calves goes up. Conversely, when the food supply is low, population growth seems to stall out or go down.

Now, thanks to the new hormonal report, we are learning that nearly two-thirds of the pregnancies among Southern Resident killer whales end in miscarriages. And, of those miscarriages, about one-third take place during the last stage of pregnancy — something highly unusual for mammals.

We are also learning that nutritional stress — caused by low food supplies — can be linked to the success or failure of the pregnancies, thanks to ongoing studies by a research team led by Sam Wasser, a University of Washington professor and director of the Center for Conservation Biology. Information about nutritional stress comes from fecal samples collected with the help of Tucker, a poop-sniffing dog who follows the whales in a boat.

I reported on Sam’s findings nearly a year ago for the Encyclopedia of Puget Sound after he presented the results during the Salish Sea Ecosystem Conference in Vancouver, B.C. His findings were published 10 days ago in the online journal PLOS One.

The hormonal information has been collected along with DNA samples from a growing number of Southern Residents, providing key information about the health of individuals as well as the overall status of the population.

Sam’s data will be included in a database being compiled to provide as much medical information as possible about each of the killer whales. I first reported details about the database in Water Ways on March 29, 2016. As mentioned in the blog, the medical files could be valuable in helping the whales throughout their range or even intervening when an animal goes into a health emergency.

General observations could be put into the database along with:

  • Fecal samples, including levels of various hormones;
  • Breath samples, including the types of bacteria harbored by individual killer whales;
  • Observations of skin conditions;
  • Photos taken from boats and from the air to show body conditions, including evidence of malnutrition or possible pregnancy; and
  • Blubber samples for some whales, including DNA fingerprints and other health conditions.

Joe Gaydos of SeaDoc Society, who is helping coordinate the database, told me that the project is finally getting off the ground this summer with formulation of the database structure. Commitments are coming together from those who can contribute information, including observations as soon as they are collected by researchers — including those with the Center for Whale Research and NOAA’s Northwest Fisheries Science Center.

A memorandum of understanding has been drafted to allow various researchers who submit information to have access to the data but limit access only to specified groups, Joe said. A governing body will oversee creation and use of the database. So far, information is being submitted on a “good-faith handshake.”

At least two research reports are being planned to prove the value of the database and build support for funding. One could be a paper that puts together information about skin diseases observed in the Southern Residents, mainly compiled by the Center for Whale Research.

Another report could look at the relationship between contaminants and pregnancy, including information collected by Sam Wasser.

“We are where we wanted to be a year ago, actively updating data,” Joe admitted to me, adding that things are now coming together more rapidly.

More information:

The latest report on orca pregnancy and nutritional stress is described in UW Today.

News stories were published by the Seattle Times as well as The Associated Press.

Previous work by Sam Wasser’s associate Katherine Ayres focuses on stresses caused by lack of food and boating activities. See PLOS One, June 6, 2012, or review the summary in UW Today.

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Hormonal studies link orca miscarriages to low chinook salmon runs

An orca mother named Calypso (L-94) nurses her young calf in this high-resolution photo
An orca mother named Calypso (L-94) nurses her young calf in this high-resolution photo taken from a drone. Lactation takes an energetic toll on orca moms. Future images may reveal whether Calypso is getting enough food to support herself and her calf.
Photo: NOAA Fisheries, Vancouver Aquarium, under NMFS permit and FAA flight authorization.

It is fairly well known that the three pods of killer whales that frequent Puget Sound are listed as endangered under the Endangered Species Act. It is also well known that their primary prey — chinook salmon — are listed as threatened.

It can’t be good that the whales are struggling to find enough to eat, but we are just beginning to learn that the situation could be dire for orca females who become pregnant and need to support a growing fetus during times of a food shortage.

Sam Wasser, a researcher known for figuring out an animal’s condition from fecal samples, recently reported that about two-thirds of all orca pregnancies end in miscarriage. And of those miscarriages, nearly one-third take place during the last stage of pregnancy — a dangerous situation for the pregnant female.

In a story published today in the Encyclopedia of Puget Sound, I report on Sam’s latest studies, along with other work by a team of biologists who are using unmanned aircraft (drones) to keep track of the physical condition of the Southern Resident orcas, including pregnant moms.

Sam’s latest study involves measuring hormones in killer whales, which can tell us a lot about a whale’s condition. The story of how hormones change under varying conditions is a little complicated, but I hope I was able to explain in my article how this works. When adding the effects of toxic chemicals that mimic hormones, we begin to understand the conditions that may be critical to the whales’ long-term survival or their ultimate extinction.

One longtime assumption, which may be shot down by the hormone studies, is that the whales’ most difficult time for food comes in winter, when salmon are generally scarce. These new studies by Sam and his colleagues suggest that the greatest problem comes in the spring, when the whales return to Puget Sound to discover that spring runs of chinook salmon can no longer be found — at least not in significant numbers.

The work with a drone carrying a high-resolution camera is providing precise measurements about the length and width of each killer whale. Pregnant females are especially interesting, and it will be important to document whether physical changes observed in the drone study can be correlated with hormonal changes seen in the other study.

“We’ve moved toward some great sophisticated technology,” Lynne Barre told me. “These great technologies combined can tell us more than any one method can … such as when and where food limitations might be affecting their health and reproduction.”

Lynne heads NOAA’s Protected Resources Division in Seattle and oversees recovery efforts for the endangered Southern Residents.

By the end of this year, NOAA is expected to release its five-year status report on the Southern Resident orcas. In addition to reporting on many new findings, the document will re-examine the risk of extinction for these killer whales and consider whether actions proposed to help them have been carried out.

Last year, the Southern Residents were listed among eight endangered species across the country that are headed for extinction unless recovery actions can be successful. The eight, selected in part because of their high profiles, are known as “Species in the Spotlight.” In February, five-year action plans were released for all eight species.

The plan called “Priority Actions for Southern Resident Killer Whales” (PDF 2 mb) focuses on three primary factors affecting the whales’ survival: a shortage of food, high levels of toxic chemicals and effects of vessels and noise. The concise 15-page document describes some of the work being carried out on behalf of the whales, although new ideas are coming forth all the time.

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Study shows ‘nutrional stress’ in Puget Sound orcas

If you can stand another scientific report about Puget Sound’s killer whales, I’d like to point you to interviews I conducted with Sam Wasser and his research associate Katherine Ayres for a story in Sunday’s Kitsap Sun.

It turns out that hormones taken from the whales’ feces tend to confirm that the animals were under “nutritional stress” this year, when seven whales died, compared to last year, when the mortality was minimal.

The unpublished information needs to undergo peer review, but the implications are many for Puget Sound restoration and what is needed for the whale population to survive.

Wasser and Ayres also hope to be able to tell whether the whales are under stress when pursued by a greater number of whale-watching boats. Stay tuned; I’ll be tracking this research as it goes along.

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