IUCN – SSC Cetacean Specialist Group

The Cetacean Specialist Group promotes and facilitates
The Cetacean Specialist Group promotes and facilitates

The Cetacean Specialist Group promotes and facilitates
The Cetacean Specialist Group promotes and facilitates
The Cetacean Specialist Group promotes and facilitate

Vaquita in decline

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No species, except perhaps the baiji, has been of greater concern to the CSG over the last several decades than Mexico’s endemic Gulf of California porpoise, the vaquita (Phocoena sinus). Already by the time of its scientific discovery and formal description in 1958, the vaquita was seldom seen, difficult to observe and probably not very abundant. Its status has continued to deteriorate since then because of the unrelenting pressure from incidental mortality in fisheries.

An ongoing decline is supported by the results of a 2008 joint Mexico-US survey, recently announced by the Government of Mexico. Whilst a survey in 1997 had resulted in an estimate of 567 vaquitas (CV=51%, 95%CI 177-1073)1 the estimate of total population size in 2008, based on a combination of visual and acoustic methods, was only 245 vaquitas2 (CV=73%, 95%CI 68-884) – a discouraging result for those who have been working hard to stop the species’ decline. The 2008 estimate was 57% lower than the 1997 estimate, implying an average rate of decline of 7.6%/year, presumably due entirely to incidental mortality in gillnets and other entangling nets.

A second study3 evaluates the Mexican Government’s national vaquita conservation action plan, which includes three options for a protected area closed to gillnet fishing.  The probability of success of each of the three options was estimated with a Bayesian population model, where success was defined as an increase in vaquita abundance after 10 years. If protection remains as it is currently within the existing vaquita Refuge Area, the chance of vaquita abundance increasing over that period is estimated as only 8%. If a larger area is protected as proposed in the PACE (see Vaquita page for details), the probability of success is still low at 35%.  The only management option judged certain of success (>99% probability) is a protected area large enough to eliminate vaquita bycatch throughout the entire range of the species. This study clearly demonstrates that if the conservation actions remain at the present level, the vaquita is unlikely to survive.

Unfortunately, despite the considerable support given to vaquita conservation efforts by the Mexican Government, the vaquita’s decline towards extinction will continue unless all entangling nets are removed throughout the species’ range.

1 Jaramillo-Legorreta, A.M., Rojas-Bracho, L., & Gerrodette, T. (1999). A new abundance estimate for vaquitas: first step for recovery. Marine Mammal Science, 15, 957–973.

2 Gerrodette, T., Taylor, B.L., Swift, R., Rankin, S., Jaramillo-Legorreta, A. M., & Rojas-Bracho, L. (2010). A combined visual and acoustic estimate of 2008 abundance, and change in abundance since 1997, for the vaquita, Phocoena sinus. Marine Mammal Science.

3Gerrodette, T., & Rojas-Bracho, L. (in press). Estimating the success of protected areas for the vaquita, Phocoena sinus. Marine Mammal Science.

Western gray whale makes unexpected journey

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In October 2010, a team of scientists from Russia and the United States satellite tagged a western gray whale off Sakhalin Island, Russia. This is the first individual from the critically endangered western gray whale population to be tagged and tracked using telemetry. This whale, nicknamed Flex by researchers, has now been successfully tracked for over 4 months, revealing its long and unexpected migration route.

There are only about 130 western gray whales left. The species is listed as Critically Endangered on the IUCN Red List of Threatened Species™, with perhaps only about 33 mature and reproductively active females. Their feeding grounds in the Russian Far East are known but details of their migration routes and breeding grounds are not. It is believed that western gray whales migrate south in the winter, towards Japan, Korea or China.

Flex stayed at Northeast Sakhalin until around mid-December, but instead of moving south as expected, he moved across the Okhotsk Sea to the west coast of Kamchatka, then followed the coast around the southern tip of Kamchatka and up along the east coast to the Commander Islands, across the Bering Sea towards Alaska, through the Aleutian Island chain and across the Gulf of Alaska. At the beginning of February 2011, Flex arrived at the US west coast off Washington State. Since leaving the Kamchatka Peninsula, Flex travelled more than 8500 kilometers over 124 days with an average speed of 6.6 km per hour during his migration.

Flex was first photo-identified off Sakhalin Island as a calf in 1997 and has subsequently been observed in multiple years off Sakhalin during the summer feeding season. To better understand his movements, photo-identification images of Flex were compared with a photo catalog of over 1000 eastern gray whales, which revealed a match. Flex had been photographed in April 2008 off the west side of Vancouver Island and then during the summer of 2008 off Sakhalin Island. This photographic match, in combination with the telemetry data, provides the first evidence that links the Sakhalin feeding ground of western gray whales to locations in the eastern North Pacific.

This tagging project represents a major international collaboration between the International Whaling Commission, IUCN, the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, the Oregon State University and the University of Washington. Funding was provided by Exxon Neftegas Ltd. (ENL) and Sakhalin Energy Investment Company (Sakhalin Energy).

For more information on the Western Gray Whale Conservation Programme, click on the following link:

New oil platform off Sakhalin – whale scientists will have a say

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The oil and gas company Sakhalin Energy Investment Company (Sakhalin Energy) announced on December 4th its intention to begin planning for construction of a third offshore oil and gas platform in the Piltun-Astokh field along the coast of Sakhalin Island, eastern Russia. As this platform would be located near the primary feeding ground of the endangered western gray whale population, Sakhalin Energy requested the advice of an independent panel of scientists, convened by IUCN, to minimize risks to the whale population.

The western gray whale population is listed as critically endangered on the IUCN Red List of Threatened Species™. Only about 130 animals remain, including perhaps 30 mature females. Western gray whales feast throughout the summer and autumn in Russian waters where oil and gas development represents a significant threat to the population’s survival and recovery.

Randall Reeves, Chairman of the independent scientific panel, commented: “We are disappointed to learn that the already large footprint of industrial development on this biologically rich part of the planet may soon get even larger. If, however, the global demand for hydrocarbon energy supplies dictates that there will be more of such development, it is vital that we push the developers to proceed in a precautionary way and protect not only the gray whales but also the seals, birds, fish and other wildlife that depend on the region’s natural productivity.”

Since 2004, Sakhalin Energy has joined forces with IUCN to minimize potential risks from the company’s operations to the western gray whale population. In 2006, at the request of Sakhalin Energy, IUCN convened a long-term independent scientific panel (the Western Gray Whale Advisory Panel – WGWAP) to advise the company on a regular basis and strengthen its monitoring and mitigation efforts.

On the first day of the 9th meeting of the WGWAP (4-6 December 2010, Geneva, Switzerland) Sakhalin Energy announced its plans to construct another offshore oil and gas platform. In doing so, the company indicated that it will continue to rely on the WGWAP for advice in assessing and addressing the added risks to western gray whales.

“This request from Sakhalin Energy builds on over 6 years of collaboration between the company, scientists and IUCN,” says Finn Larsen, Programme Officer, IUCN Global Marine and Polar Programme. “However, it is the first time that the WGWAP will be providing advice at such an early stage in the planning of an offshore platform. This should ensure that best practices are maintained through the whole development process and it is a good example of how industry and the conservation community can work together to minimize the impacts on an endangered species.”

For more information, please visit: www.iucn.org/wgwap

Contacts:
Finn Larsen, Programme Officer, IUCN Marine and Polar Programme, finn.larsen@iucn.org
Beatrice Riche, Logistics and Communications Officer, IUCN Marine and Polar Programme, beatrice.riche@iucn.org