Here is a nice example of an attempt to put some quantitiative 
figures on extinction risk, and for one of the most beautiful 
species on the planet.
 

Details of the populaitn viability analysis can be found at:
 

http://www.biologicaldiversity.org/swcbd/species/orca/index.html

Best wishes

David Duthie
 

********************************************************************* 
Seattle Post-Intelligencer   Friday, February 23, 2001 
 

Risk of orca extinction underscored in analysis 
 

By ROBERT McCLURE 
 

Imagine the sheltered waters of Puget Sound unbroken by the 
playful leaps and splashes of the killer whale. 
 

Hard to believe? 
 

Not according to a statistical analysis released yesterday saying 
that, after thousands of years in the waters of Western 
Washington, orcas here could disappear in a matter of a century or 
two. There is a 4-out-of-5 chance that the whales -- searching 
harder for food as fish stocks plummet, threatened by pollution 
and perhaps other causes -- will go extinct by 2300, the study 
says. 
 

And the orcas that call Puget Sound, the San Juan Islands and 
other western Washington waters home, now numbering 84, could 
vanish even earlier in the case of a massive oil spill or similar 
catastrophe. That's according to a study by the Center for 
Biological Diversity, an advocacy group that often sues the 
government to protect animals under the Endangered Species Act. 
 

An oil spill or similar disaster that wipes out one-tenth of the orcas 
could push the risk of extinction low enough to extinguish the 
whales in just over a century, the analysis shows. 
 

"There's reason to be very concerned about these whales," said 
Kieran Suckling of the Center for Biological Diversity, which is 
based in Tucson, Ariz., but maintains a part-time office in the San 
Juan Islands. "We need to take action now, while there's still time." 
 

The analysis by center scientists used a standard computer model 
that considers eight factors including the animals' ability to 
reproduce, their death rates and their population fluctuations since 
researchers began following them a quarter-century ago. 
 

Because the center's scientists used a computer model, their work 
is full of assumptions. But they are assumptions based on what 
whale biologists have observed in the past, Suckling said. The 
scientists working for the environmental group asked government 
researchers and others to review the report before its release to
make sure they were on target. 
 

"We don't want to give a false sense of precision to (the 
predictions), but (center scientists) are not just sitting around 
throwing coins," Suckling said. 
 

Their information on the whales' past population variations came 
from the Center for Whale Research in Friday Harbor, where 
biologist Ken Balcomb has been following the whales since 1976. 
Balcomb agrees with the thrust of the report. 
 

"We see the same basic trends, and it's nice to see a pretty 
professional job of going through the statistics of it," Balcomb said. 
"There's something going on. It's something we're trying to bring to 
the attention of National Marine Fisheries (Service) and the public 
so that whatever can be done about it is done." 
 

What's going on? No one knows for sure, but some factors are 
obvious: 
 

In the 1950s, the Canadian and U.S. air forces were known to use 
the orcas for target practice. They also were shot by fishermen 
who feared their competition for fish. 
 

>>From the 1930s to the 1970s, chemicals known as polychorinated 
biphenyls were used to cool and lubricate electrical components. 
Because of their high toxicity, they were banned. But by then 
PCBs had been unleashed through dumping worldwide, including the 
waters of Western Washington. Tests in recent years have shown 
that Western Washington's orcas have the highest levels of PCBs 
known in any mammals -- four to five times higher even than 
beluga whales in Canada's St. Lawrence estuary, whose 
contamination is known to lower the birth rate, sap their immune 
system and cause subtle physiological disturbances. 
 

More than 30 juvenile orcas were captured and taken away in the 
1960s and '70s to be shown at marine theme parks. But this does 
not explain all of the decline; separate group of killer whales in 
British Columbia, where juvenile orcas also were captured, has 
rebounded nicely while those concentrated in the San Juan Islands 
and points south have not. 
 

Some stocks of salmon, herring and other fish eaten by killer 
whales are in steep decline. Because of this, the whales may be 
turning to halibut, rockfish and other species that inhabit the floor 
of the sound -- which is where PCBs accumulate in the sediments. 
 

In addition, some scientists wonder whether at least some slight 
damage might be inflicted by the fleet of whale-watching boats that 
has sprung up in recent years as the orcas went from reviled to 
revered. But there is little evidence of any impact. 
 

The center's report will be part of its planned attempt to persuade 
the National Marine Fisheries Service to protect the whales under 
the Endangered Species Act. 
 

A group of government scientists concluded last year that the 
orcas' plight is worthy of "considerable concern," but stopped short 
of saying they should be declared endangered under the law. 
 

Paul Wade, a marine biologist with NMFS' National Marine Mammal 
Laboratory in Seattle, said that in the quarter-century the whales 
have been followed, they have showed alternating patterns of 
increasing and decreasing population, each lasting roughly six 
years. 
 

"It's not really that certain what's been going on," Wade said. 
"Another six years should tell us a lot. If the population continues 
to go down in six years, we're going to be pretty worried about 
them." The study released yesterday, though, says that the last
six years are different from the earlier decline. While elderly and 
young whales died off before, now the deaths include whales of 
reproductive age. 
 

Suckling, of the Center for Biological Diversity, said the solutions 
lie in learning the origin of the PCBs that are getting into the orcas 
and taking strong steps to help salmon and herring populations 
rebound. To him, that means breaching fish-killing dams, curtailing 
logging in watersheds where salmon spawn, and refusing to allow 
continued industrial development at Cherry Point, a major herring 
spawning ground where the herring are mysteriously disappearing. 
 

A major factor not considered in the report, but which is bound to 
have some effect on the whales and their prey, is what many 
scientists now characterize as the seemingly unstoppable shift of 
the world's climate in a warmer direction. 
 

Said Balcomb of the Whale Research Center: "We're just going to 
have to cross our fingers and watch carefully and not make the 

mistakes we've made in the past."

Dr David Duthie (Programme Co-ordinator)
UNEP/GEF Biodiversity Planning Support Programme
T-133
PO Box 30552
Gigiri
Nairobi
KENYA

Tel: +254-2-623717
Fax: +254-2-624268/623162
E-mail: david.duthie@unep.org
BIOPLAN is an electronic list server established by the UNDP-UNEP implemented
 Biodiversity Planning Support Programmme and maintained by UNDP-GEF to serve the
 global community involved in planning for national implementation of the Convention on
 Biological Diversity. To unsubscribe (remove yourself) from this list send a message to:
 majordomo@undp.org with the subject line BLANK and the following text in the body of
 the message: UNSUBSCRIBE  BIOPLAN followed by your e-mail address,
or go to http://stone/undpweb/bpsp/bioplan.cfm

BACK TO LISTINGS   HOME