Marine Biologist Brad Hanson detailed Killer Whale research
Marine Biologist Brad Hanson of the Northwest Fisheries Science Center spoke at the Duwamish Longhouse about the state of research on the Southern Resident Killer Whale population.
Thu, 11/11/2010
In the second orca related event of the last five days in West Seattle (the first was Orcafest on Nov. 7) Marine Biologist Brad Hanson, from Northwest Fisheries Science Center provided a "Research Update" with an unusual but honest title "In search of spew, poo and goo - Learning about Orcas from what they eat" at the Duwamish Longhouse Wednesday, Nov. 10.
Hanson first became enamored of orcas with one of the first ones ever captured, Namu, in 1965, and at the age of 10 spent hours near the whale and others that followed. "The trainers would give me a ball and I'd play with the whale all day," he said, "things were a lot looser back then."
He took that early fascination and built it into a career as a marine biologist. The knowledge gained since then is, "like a quantum leap," Hanson explained, and that the Pacific Northwest "really was in fact the epicenter for this whole change (…) in terms of cetacean research."
Hanson's research update outlined, in sometimes dizzying detail how researchers go about learning where orcas go, what they eat, and what we can learn about them from materials collected from and around them.
Hanson explained that "Senator Cantwell, back in 2003 got a line item of funding started and that has continued (…) It's now a permanent part of the NOAA budget. There is about $750,000 every year that's allocated to Southern Resident Killer Whale (SRKW) research.
He described some of the history of research on killer whales beginning with the early captures ( which ended in 1977) and the subsequent growth of sophistication including a "Photo ID" effort that documents whales by tracking their dorsal fins and other markings. While a lot can be learned from animals in captivity the health of those in the wild, how they live, and what they depend on is the focus of his research.
The report dealt with the SRKW population (J, K and L pods comprising 85 animals) that occupy the waters from the Queen Charlotte Island area to as far south as Monterey, CA.
Researchers use observations of whales from the shore or marine craft to then approach them in order to collect samples of fecal matter, or mucus left by the orcas for later DNA and other chemical analysis. They scoop the material up with nets and also collect bits of the prey, most commonly Chinook Salmon the SRKW's preference. From the feces they can learn what the overall diet of the orca consists of and detect any other chemicals that might be present in their prey.
"Orca's are messy eaters" said Hanson, who also described their prey sharing behavior in which they break the fish down into bite size chunks and share with others in the pod. From collected samples of the fish it can be learned which river or hatchery the fish came from. The update pointed to the Fraser River in Canada as being of primary importance for orcas as a source for their primary diet.
They consume approximately 30,000 pounds of fish a month or very roughly 100 pounds each on average per day.
The SRKW population saw a decline in the 90's of some 20% which led to a petition to list them under the Endangered Species Act. A primary concern was the low number of reproductive age animals, especially adult males. One aspect that makes accurate research more problematic is that Killer Whales are so much like us. They can live into their 80's.
The lessons learned from this research have implications for the larger marine environment. "They are at the top of the food chain, "said Hanson," and if they are not doing well then something lower in the food chain is likely in trouble."
What does the future look like for orcas? "It could be challenging," he said, "It depends on the time frame you are talking about (…) One of the things we had to grapple with in the biological review board is 'What does extinction look like?' because they could be functionally extinct where the population isn't gone, they might live fifty years but there's not enough reproductive age animals to keep the population going.
We ran population viability scenarios and extinction was one of the scenarios that came out."
The event was sponsored by theWhaleTrail.org.