Killer whales love to dine on chinook salmon, which could further endanger their future

Turns out the killer whales off the San Juan Islands are picky eaters. They prefer a meal of chinook salmon to anything else — and it could further endanger them. They compete with sport and commercial fishermen, and tribes for the prized fish, whose numbers have steeply declined.....
http://www.oregonlive.com/news/index.ssf/2009/09/post_7.html

Killer Whales are not going to dictate the survival and or strength of salmon runs.

WE ARE!

Unfortunately this doesn't leave me with a good feeling about the outcome.

CNB

Where do you apply for an Orca tag?

Heard they were for sale in Neah Bay.

They don't tag them at Neah Bay they just kill them and let them sink, so I guess they are feeding the crabs.

I'm having trouble with the notion that an apex predator like Orcas would be so forage specific - chinook - as to forego other available forage to the point of becoming ill, unfit, or even starving. It isn't like they're a species of finch on the Gallapogos (sp), with a beak sized and shaped for one specific kind of seed, making them ineffecient or unable to forage on other seed types. An Orca can eat any damn thing it wants, and if chinook are in short supply, exactly what physiological or behavioral limit is preventing it from grabbing a sockeye, pink, chum, hake, or a seal? Yeah, I read about the learned behavior, but that doesn't make the animal incapable of learning an alternate behavior. Something about this hypothesis isn't adding up.

Sg

Just because one food is prefered over another doesn't mean that it's an exclusive food source.

I remember some reports from Alaska several years ago that had outlined a scenario such as this...

As Chinook populations crashed, killer whales shifted to eating other things, including otters. When the otter population went down, the sea urchin population went through the roof, and sea urchins eat kelp.

Kelp beds were shrinking...and kelp beds are the predominant spawning substrate for herring...herring populations were being affected, which further affected the food base for the Chinook...

Viewing the environment as anything but one holistic and interconnected web can have serious consequences, to say the least.

Fish on...

Todd

I had heard that these West Side Orcas NOAA is focusing on, are an elite group. They only prefer dime bright chinook. Anything less than that and they turn up their fins. Humpys......they are so laffin'

makes little sense anymore...

This appears to be a fisherman's statement of Gaia theory, something that so many discussions on PP come to.

Gaia Theory

Over 150 years ago, Suquamish Chief Sealth is supposed to have said:

“What is man without the beast. If all the beast were gone, man would die from a great loneliness of spirit, for whatever happens to the beast, also happens to man. All things are connected.”

I wonder if the Orca decline has anything to do with less delayed release hatchery Chinook designed to stay In the sound?

i thought there was a study that said the resident blackmouth were making them sick because they are so full of toxic`s from living in the sound ?, i think there is even a health advisory for us to only eat one meal a week of resident puget sound salmon.

Wouldn't that make them the Parker Pod then ?!?!

We're gradually shifting away from yearling releases but increasing the numbers of zeros that will be released. Return to creel looks to be about the same. In years past, it is my understanding that a fair number of the delayed releases were being caught in Canadian waters.

another famous indian with great wisdom:

Chief Wild Eagle, leader of a peaceful tribe of Hekawi indians who lived on the Kansas Frontier of the 1860's. As he often said "Hekawi's not fighters...invent peace pipe. Hekawi's not mad at Nobody!"

dexter's law: Dexter: It's said that everything is connected to everything. The butterfly effect. You drop a pebble into a pond and the ripples radiate outwards touching and effecting everything. Until finally a fish grows arms and legs and crawls out of the water...and picks up a rock and smashes the next two fish over the head...and we have the first serial killer.

Sg

There is a study I saw a few months ago that showed orca selected chinook, acoustically, when presented with similar sized salmon of a least a couple of species. Like you, I would find it surprising that an apex predator would be so food selective.

But, wolves apparently have preferred prey. When they put the wolves in yellowstone they chose animals that were elk-eaters rather than deer or moose. Certainly not 100%, but they do concentrate on them.

Also, we know that when grizzlies eat salmon their age at maturity is younger, females produce more cubs, the animals are more social and live at higher densities. When they don't have access to an abundant protein source they mature at an older age, produce fewer cubs, and are not at all social. In short, they need a lot more area to support fewer animals and their population productivity is lower. In short, they are more sensitive to the loss of any animal.

In the North Pacific it appears that thwe whaling in the 1950s is what triggered (eventually) the shift in killer whale diet to otters and all the associated problems with that.

Long-winded way of saying that the residents may well eat other fish but the result may be a less productive population. Which is more sensitive to disturbance and loss of young for whatever reason.

So Grizz......maybe you know......Where the Hekawi now?

Carcassman,

I'm not denying the possibility, but since it runs counter to general ecological principles, the explanation, or hypothetical explanation, ought to accompany the statements about this prey selectivity. Absent a meaningful context, it comes at me like the advocates don't think anyone else studied biology and ecology.

Ecological relationships make sense if we study them. The Yellowstone wolf example is a good one. Wolves that prefer elk made sense because the YNP elk herd was too large for its range, and a large % of the population consisted of cows beyond calving age. Hence the population had reached a level of low productivity. This doesn't mean those wolves won't, and haven't, selected other prey, deer and livestock, moose - not so much, when they expanded into areas where those prey were a better fit to optimal foraging theory.

The sea otter, urchin, kelp, herring story is another one that makes sense. But this Orca story isn't making sense to me. I can understand preferring chinook. I prefer chinook too, as a matter of fact. But it doesn't take exclusive prey selection theory to persuade me to eat sockeye, coho, New York steak, chicken, or pork chops to satiate me and keep me far, far from starvation. I can understand having learned to hunt and select for chinook. What I'm having trouble with is the associated corollary that in the absence of chinook an Orca will choose starvation over the rather slight behavioral change to eat whatever fish is abundant, absent a clear, cogent, and convincing explanation. That's all I'm asking for, and then I could be a believer.

Sg

The mink in Alaska give birth just prior to the arrival of chinook on the spawning grounds. This allows the mothers, who consume the salmon, to produce lots of good milk.

Perhaps the orcas, particulalry females, target chinook as a source of high quality fats, for lactation soon after birth. Lacking the high fat food supply at that time of year, calf survival may be reduced. The temporal and spatial issues of when they eat chinook needs tyo be looked at.

Obviously, they won't be eating them all year in Puget Sound because they probably weren't here in great numbers all year. But, their presence at particualr times and places may be critical.