Are we loving our whales to death?
Motorized Whale-Watch Boats May Play A Primary Role In Orca Population Decline
posted 06/10/02
Three separate scientific studies released June 1, 2002 show that motorized whale-watching boats may play a primary role in the decline of the southern resident Orca population.
Since 1995, the southern resident population of Orcas (which spend between six and eight months of the year in the San Juan Islands) has declined by almost 20 percent. During that same period, the number of motorized whale-watching boats in the area has increased dramatically - to more than 80 commercial whale-watch boats nowadays.
All three studies released today were commissioned by Orca Relief Citizens' Alliance. They represent the first scientific studies specifically commissioned to answer the question: What is killing local Orca whales?
The first study, conducted by University of Washington researchers Dr. Glenn VanBlaricom and Carlos Alvarez-Flores, shows a strong statistical correlation between whale population decline and boat activity.
The second study, written by Dr. David Bain, University of Washington, suggests that t noise from motorized boats may decrease the orcas' efficiency in obtaining prey by 95-99 percent.
A final study was conducted by Dr. Birgit Kriete, who has since been hired to be Executive Director of Orca Relief. The Kriete study shows that the whales' energy requirements have increased by almost 20 percent for adult killer whales compared to the years when no or very few commercial whale watch boats were in operation. The paper suggests this is likely caused by stress resulting from constant boat traffic near the whales, causing higher metabolic rates and therefore higher energy requirements.
"The combination of these three research studies gives us the first clear story of what appears to be killing the whales," says Mark Anderson, President of Orca Relief. "For the first time, we can put all of these various causes into a sentence, based upon scientific research:
"In an environment of declining salmon, the presence of the whale watch fleet may decrease the whales' acoustic ability to find prey by 95-99 percent, while increasing their food requirements by up to 20%; the resulting starvation forces the whales to consume their toxin-laden blubber, and they die."
The three studies were released just prior to the weekend Orca Recovery Conference held at the University of Washington, attended by more than 100 scientists and non-government organization members interested in saving Orca whales.
About Orca Relief
Orca Relief Citizens' Alliance was founded in 1997 as a non-profit 501(c)(3) organization. Orca Relief was formed to focus specifically on discovering the causes of increased Orca mortality, and in eliminating these causes.
Study Summaries
Dr. Glenn VanBlaricom and Carlos Alvarez-Flores
University of Washington
Survival rates in the southern resident orca (SRO) population were found to vary over time, with different age and gender classes showing different patterns of temporal variation. Survival rates declined most strongly for males and especially old males over the time course of the analysis (1974 through 1999). Survival rate also declined for old females. Calf survival was more variable than any other age or gender category. Despite the suggestion of declining calf survival in the data, however, variance over time was sufficiently high that the apparent temporal trend was not significant.
Of covariates evaluated, boat activity was most strongly correlated with the trends in survival described above, followed by salmon abundance, except that the apparent trend in calf survival was sensitive to the specific model used. Sea surface temperature, a proxy for a number of important environmental processes, did not correlate well with survival trend. Contaminant effects could not be evaluated as a covariate because of the absence of a time series of data. Finally, a simulation analysis indicated that demographic stochasticity alone could explain observed trends in the SRO population at least through 2000. Our analysis suggests the possibility of a combination of anthropogenic factors and random demographic variation are contributors to declines in the SRO population.
Quote from Paper: "Of covariates evaluated, boat activity was most strongly correlated with the trends in survival described above [a declining population]."
Dr. David Bain
University of Washington
The southern resident killer whale (Orcinus orca) population declined from 98 to 79 animals from 1995 through 2001. While reduced prey availability and exposure to toxic chemicals are widely accepted as potential contributing factors in the decline, the suggestion that whale watching traffic may also play a role is more controversial. We combined three analytical models with changes in behavior measured in northern residents and approximate levels of whale watching traffic experienced by southern residents to estimate population-scale effects. These effects would result from increased energy expenditure due to avoidance responses and reduced energy acquisition due to acoustic impairment of foraging efficiency. Our models indicate that population-level effects are negligible for killer whale populations well below carrying capacity (K). Thus population growth in the presence of disturbance cannot be used to conclude that disturbance will not affect the population at higher densities.
We demonstrate that missed prey due to noise is potentially a more important mechanism than excess energy expenditure. The high value of the shape parameter (z) of the killer whale population growth model suggests that the maximum net productivity level is over 80% of K, rather than the NMFS default of 50-60%. Similarly, the Potential Biological Removal level calculated with z=1.0 is too high. Southern residents are currently below their maximum net productivity level and should be considered a depleted stock. Any human-induced mortality or serious injury at levels exceeding one individual every 2-10 years needs to be reduced. The best estimate of the effect on carrying capacity of whale watching at current levels is about 3% due to excess energy expenditure, but insufficient data are available to reliably estimate the impact of noise.
Clearly, more data are needed to determine whether the actual impact of whale watching that our models predict exceeds "insignificant levels approaching zero." However, the precautionary principle supports mitigating potential impacts until data become available to indicate that regulations or guidelines are unnecessary.
Quote from Paper: "In the absence of knowledge about prey distribution, this would result in a reduction of available prey by over 95%. --- With outboard powered whale watching, even under present guidelines, there would be losses of similar magnitude relative to the already reduced level from other sources of ambient noise (i.e., total reductions in excess of 99%)."
Dr. Birgit Kriete
Orca Relief Citizens' Alliance
This study provides a comparison of the physiological changes of the southern resident killer whale population from a period of very little boat traffic to an era of increased marine vessel commerce, and it clearly indicates that increased boat traffic has a negative effect on the whales. The regular physical activity of the southern whales has increased in recent years. Swimming velocities and respiration rates of the southern whales have shown statistically significant increases over that of the mid-1980's,
The increase in swimming velocity is metabolically very costly and carries high energetic costs. It was determined that adult killer whales expended close to 20% more energy due to increased swimming velocity in 2001 compared to the 1980's. Any increase in swimming velocity and respiration rate needs to be balanced by an increase in food consumption in order to pay metabolic debts. With the decrease in salmon stocks, this poses an additional threat to the orcas. If energetic demands cannot be met, females might not be able to satisfy high feeding demands of calves, adipose tissue is reduced, which concentrates the level of toxins remaining in the blubber, immune systems are weakened and reproductive success is reduced. Decreased fecundity and survivorship will all lead to a reduction in population size.
Quote from Paper: "It appears, therefore, that the significant environmental change that may contribute to the change in energy expended is the increase in whale watch traffic."
Fact Sheet
- Researchers have identified four populations of killer whales in the waters of Washington State and British Columbia that are socially and ecologically isolated from each other. The population we are most concerned about is the Southern Resident Community, the population most affected by humans and whale watching. This group of orcas resides in Haro Strait, between the southern end of Vancouver Island and Washington State for much of the spring, summer and fall.
- The number of killer whales in the Southern Resident population in May 1995 was 98. This number had decreased to 83 whales by October of 1999. In 2001, there were 79 killer whales left in the southern resident population. This is an almost 20% decline in the population in just 6 years, from 1995 to 2001.
- What is causing the decline in killer whales? There are three components: decrease in the amount of prey available, toxins (especially PCB's in the marine environment), and the increase in the number of whale watching boats.
- Starting in 1994, the number of killer whale deaths increased at the same rate as the number of commercial whale watch boats increased. There were no whale watching boats in 1976. In 1985, there were 10. By 1994, there were 42. In 2001, the number of whale watching boats had increased to 82. That is a 50% increase in boats from 1994 to 2001.
- In 1990, pods of killer whales in southern BC were accompanied by an average of 4 vessels at any one time during summer daylight hours. By 1997, the number had grown to 25 vessels at one time. Often, more than 40 whale watch vessels are seen on the west side of San Juan Island accompanying the whales during the summer months. Many scientists believe that the numbers of vessels pursuing killer whales will likely continue to grow parallel with the public fascination for whales.
- Killer whales are accompanied by boats more than 25% of the time during the year - 50% of the time during the 8-10 months whale watching season and 100% of the day light hours.
- Problems with boats around killer whales:
1) Underwater noise from the boats can inflict pain;
2) Whales inhale the diesel fumes that boats let off;
3) Whales can ingest toxic oil that is discharged into the water in regular engine use;
4) Killer whales swim faster and farther when followed by boats. This means that they have to eat more to be able to compensate for the extra energy needed to swim. If they cannot find enough food they will use up their blubber layer, concentrating toxins. This can cause the animals' immune systems to weaken and lead to an increase in chronic illnesses, reduced reproductive success and higher mortality.
5) Engine noise makes it very difficult for the whales to locate food and communicate with each other.
Biographies
Mark Anderson,
Founder and President, Orca Relief Citizens' Alliance
Mark Anderson is the founder and president of Orca Relief Citizens' Alliance, a non-profit organization aimed at reducing the death rates of killer whales. He is also a director of The Hybrid Vigor Institute, a new effort to improve the quality and quantity of scientific discoveries by providing new platforms and tools for enhancing interdisciplinary research.
Mr. Anderson is also a leading international analyst and forecaster on trends in information technology.
He is the founder of Strategic News Service (SNS), the first subscription-based newsletter on the Internet, which is read by industry leaders and investors worldwide.
Mr. Anderson is also president of Technology Alliance Partners, which provides trends and marketing alliance assistance to countries and companies interested in the convergence of telecommunications and computing.
He is the founder of the Washington Software Alliance Investors' Forum, Washington's premier software investment conference, and he has participated in the launch of many software startups.
Mr Anderson is a member of the Merrill Lynch TechBrains Advisory Board and is involved as an investor or advisor in Authora, ONTAIN, Ignition Partners, Voyager Capital and Mohr Davidow Ventures. He is also a principal in the investment advisory firm Resonance Capital Management, which manages the accounts of institutions and high-net-worth investors focused on technology markets.
Mr Anderson has lectured at the universities of Stanford, Harvard, and Washington.
Birgit Kriete , Executive Director, Orca Citizens' Alliance
Birgit Kriete, Ph.D. brings nearly 20 years of whale research experience in Europe and North America to her position as Executive Director at the Orca Relief Citizens' Alliance (ORCA). ORCA is a non-profit effort to study and reduce Orca mortality rates.
Dr. Kriete obtained her Ph.D. as a whale researcher through the University of British Columbia in Vancouver, B.C. in 1995. Her dissertation on "Bioenergetics in the killer whale, Orcinus orca" focused on the physiology of killer whales. She has been an independent research ever since.
Her many years of studying whales includes serving as research and education director at The Whale Museum in Friday Harbor, Washington, as well as a research intern and assistant at the Center for Coastal Studies in Provincetown, MA, where her work included research on right, humpback and fin whales, focusing on prey items of the endangered North Atlantic Right Whale. Dr. Kriete also conducted research on the "Killer Whale Population Assessment in Sweden and Norway" through Memorial University in St. John's, Newfoundland.
Birgit Kriete currently resides in Friday Harbor, Washington.
Glenn VanBlaricom
Glenn R. VanBlaricom is an Associate Professor at the School of Aquatic and Fishery Sciences, University of Washington (UW), and is the Assistant Unit Leader (Wildlife) of the Washington Cooperative Fish and Wildlife Research Unit. He has a research group of nine currently enrolled graduate students (7 PhD, 2 MS). Five doctoral and five MS students have graduated from the UW Program since it was established in 1993. VanBlaricom has 41 publications in the technical literature and has made 122 formal research presentations, including 49 invited presentations, at professional conferences and university seminars. He has published two books (one technical, one non-technical) on sea otters. He has served two stints (8 years total) on the Board of Governors of the Society for Marine Mammalogy (SMM), is currently a candidate for the office of SMM President-elect, and is a former member of the Board of Editorial Advisors and Referees of the international research journal Marine Ecology Progress Series. He received Bachelor of Science degrees in Zoology and Oceanography in 1972 from the University of Washington, and a PhD in Oceanography from the Scripps Institution of Oceanography, University of California, San Diego, in 1978.
The VanBlaricom research group is interested in the conservation biology and trophic and community ecology of marine mammal populations, with particular emphasis on coastal species of the North Pacific Rim and the Arctic region. Among current activities are: studies of predation by harbor seals on depleted salmon populations in Puget Sound and southern coastal British Columbia; studies of beluga whale population dynamics and habitat utilization in Cook Inlet; studies of habitat utilization by belugas and narwhals along the Arctic coast of Canada; population dynamics of killer whales in the Bering Sea, northern Gulf of Alaska, southern British Columbia, and Puget Sound; population dynamics of gray whales in the Russian Far East; interactions of the tuna purse-seine fishery with pelagic dolphin populations in the eastern tropical Pacific; population estimation for minke whales in wintering grounds off Brazil; migratory corridors of humpback whales in the southwest Atlantic; and the community ecology of sea otter populations in Washington. The VanBlaricom group is also involved in coastal benthic ecological studies, including the population biology and conservation genetics of black abalones in California, the effects of disturbance by geoduck fisheries on benthic ecosystems in Puget Sound, and habitat and ecosystem associations of deepwater benthic rockfish populations off the Washington coast.
VanBlaricom has two daughters, both graduates of the University of Washington (Betsy in Business Administration, Christy in Psychology). With his wife Kristina he enjoys birding, reading, and scuba diving (the latter in warm places) when time permits.
Carlos Alvarez-Flores,
Doctoral candidate at the School of Aquatic and Fishery Sciences, University of Washington
Carlos Alvarez-Flores is a Doctoral Candidate at the School of Aquatic and Fisheries Sciences of the University of Washington. He works under the supervision of Glenn VanBlaricom, Assistant Unit Leader (Wildlife) of the Washington Cooperative Fish and Wildlife Research Unit. He is also under the supervision of Douglas DeMaster currently Science and Research Director of the Alaska Fisheries Science Center of the National Marine Fisheries Service. Carlos is a citizen of Mexico where he got his MS degree in Science (Biology). His research interests are directed towards applications for the management of activities that affect marine mammal populations and wildlife in general. He initiated in Mexico many of the now successful cetacean photoidentification efforts. He has also worked as a private consultant for the governments of Mexico, the USA and Greenland. He has also conducted private consulting research for the private sector and for international organizations of different nature such as Greenpeace and the North Atlantic Marine Mammal Commission. Carlos is expecting to defend in July his dissertation on the incorporation of uncertainty in the management of activities that affect marine mammals utilizing as a case study the problem of dolphin mortality in the tuna fishery of the eastern tropical Pacific Ocean.
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