Therefore … isn’t it obvious that the shortage of Puget Sound
chinook has had a major impact on the whales?
Once you begin to challenge the assumptions — as a seven-member
scientific panel has done — a more complex picture emerges. It is
not easy to sort out predator-prey interactions, especially
considering that the prey may include hundreds of individual salmon
stocks, some of which are doing quite well.
The
independent panel (PDF 144 kb), made up of U.S. and Canadian
scientists, tackled the question of whether cutbacks or elimination
of salmon fishing could help rebuild the killer whale population at
a faster rate. The panel’s preliminary conclusion is that reducing
fisheries could have a slight benefit, but only if certain
assumptions hold true.
An axiom among orca observers goes something like this: When you
believe you have figured out what killer whales will do, they’ll do
something else.
I’ve become accustomed to writing an annual story that lets
people know when chinook salmon runs are dwindling in the northern
waters of Puget Sound and the Strait of Georgia and when chum
salmon runs are beginning to build up in South Puget Sound.
It happens in the fall, and it generally means that our Southern
Resident orcas will begin checking out the buffet table in areas
from Whidbey Island to Tacoma and occasionally as far south as
Olympia. During this time, ferryboat riders aboard the Kingston,
Bainbridge Island, Bremerton and Vashon Island ferries begin seeing
the whales more frequently.
It appears that the table is now set and waiting for the whales,
but that doesn’t mean they’ll show up for dinner on time, as I
describe in a story I wrote for
yesterday’s Kitsap Sun.
Lots of people reported seeing the orcas last week, when they
were spotted from all the usual ferries, including some rare
sightings on the Mukilteo run. The video on this page was taken at
Point Robinson on Vashon Island and shows how exciting it can be to
watch whales from the shore.
Although the Southern Residents showed up in South Sound only
twice in October, historical records reveal that as long as chum
are around, the whales — most notably J Pod — can be expected to
return through December. One analysis of whale movements was
conducted as part of a tidal energy project for the Snohomish
County Public Utility District.
See Marine Mammal Pre-Installation Study (PDF 12.9 mb). (Note
the large file.)
While the Southern Residents are known to eat chum in the fall,
there is no doubt that their preferred prey is chinook salmon,
which are listed as threatened under the Endangered Species Act.
How to make sure the orcas are getting enough chinook to eat is
part of a major study effort now under way, including a series of
workshops about the effects of salmon fishing on the killer
whales.
The annual North of Falcon process is about to get under way
again, beginning with a public meeting in Olympia on Tuesday.
During Tuesday’s meeting, state, federal and tribal managers are
expected to outline their preseason forecasts of abundance for each
salmon species. See meeting announcement in the
Kitsap Sun and on the North of Falcon
website.
Chinook salmon are the
primary prey for Puget Sound's killer whales. Here, J-40 grabs a
fish off False Bay, San Juan Island
Photo by Astrid Van Ginneken, Center for Whale
Research.
This year, there will be a new elephant in the room … actually,
something as large as an elephant — a killer whale. But more about
that in a moment.
The process of determining how many salmon of each species are
available for harvest and how to divide up the catch has become a
complex project involving commuter simulations, policy discussions
and demands from fishing constituents. The goal is to make abundant
stocks of salmon available for harvest while protecting “weak runs”
— particularly those listed under the Endangered Species Act.
Sure, the process has its flaws, but I have not heard of any
better ideas for protecting weak runs outside of stopping all
fishing for a period of time. So far this year, I haven’t had time
to get a head start on what salmon managers are thinking, but I’ll
be following the discussions as they move along.
I’ve been thinking about the comments people sometimes post on
this blog, blaming all the salmon problems on commercial fishing,
tribal fishing or the locations of fishing nets. Because such
comments are often based on a lack of knowledge, I was wondering if
such folks ever consider attending these meetings to find out how
fishing decisions are made. The meetings, which are open to the
public, begin with general discussions and get more technically
oriented right up to the point when final decisions are made in
mid-April.
While the fishing issues are complex by themselves, it is
becoming clear that anglers and tribal fishermen may soon need to
share their chinook salmon — a highly prized sport and table fish —
with another species, the Southern Resident killer whale, an
endangered species.
In a
letter to salmon managers (PDF 1.5 mb), Will Stelle, regional
administrator for the National Marine Fisheries Service, announced
that he would convene a series of workshops to study the
relationship between chinook fishing and the survival of the Puget
Sound orcas:
“The basic question NMFS must answer is whether Chinook salmon
fisheries that affect the abundance of prey available to the killer
whales are significantly and negatively affecting the well-being of
the Southern Resident population and, if so, how those negative
effects might be reduced.
“At the conclusion of the scientific workshop process, NMFS and
others will be better able to determine what recovery actions are
appropriate and, more specifically, whether and under what
conditions additional constraints on salmon fishing may be
necessary.”
As recently as 2008, the federal agency concluded that fishing
at the levels allowed through the North of Falcon process had no
serious effects on the whales. But, according to Stelle, more
recent analyses may show otherwise:
“Our conclusions, which are preliminary at this point, strongly
suggest that the amount of Chinook available to the whales in
comparison to their metabolic requirements is less than what we
estimated in the 2008 consultation, particularly during those
summer months when the whales spend considerable time foraging in
the Salish Sea.
“This change results from several factors, including but not
limited to revised estimates of the metabolic requirements of the
whales, their selective preference for larger Chinook salmon, and
inclusion of a broader range of years to represent expected
variations in the abundance of Chinook salmon available to the
whales.”
While allocations for killer whales may not be explicit this
year, the workshops could result in reduced harvest under the next
Puget Sound Chinook Management Plan. For a more detailed discussion
of the early analysis, download “Effects
of Fisheries on Killer Whales” (PDF 345 kb).
