Workshop Report Released: Determining and quantifying threats to coastal cetaceans

Determining and quantifying threats to coastal cetaceans:  A regional collaborative workshop: 21-24 February 2011, Kuching, Sarawak, Malaysia, Edited by G. Minton and B.D. Smith.

In February 2011, 27 cetacean researchers from the South Asian region came together at the Permai Rainforest Resort in Kuching, Sarawak to discuss means to better incorporate threat assessment into conservation-based research on coastal cetaceans.The core participants were from Peninsular and East Malaysia, Bangladesh, Brunei, Hong Kong, India, Indonesia, Myanmar, the Philippines, Sri Lanka and Thailand, with international representation from the USA, Australia and Britain. The opening ceremony included presentations and participation by local stakeholders, academics, and NGOs.The emphasis was on small cetaceans with near- and inshore distributions that do not extend beyond the continental shelf: the Irrawaddy dolphin Orcaella brevirostris, finless porpoise Neophocaena phocaenoides, Indo-Pacific humpback dolphin Sousa chinensis, and Indo-Pacific bottlenose dolphin Tursiops aduncus. Participants also recognized that nearshore waters in Southeast Asia provide vital habitat for populations of some pelagic species (e.g., spinner dolphins Stenella longirostris and dwarf spinner dolphins, S. longirostris roseiventris) and support at least two large baleen whales: small-form of Bryde’s whales Balaenoptera edeni and Omurai’s whales B. omurai.

The report begins with a powerful foreword by Randy Reeves, IUCN Cetacean Specialist Group Chair, and includes abstracts from the core presentations of the workshop, summaries of panel discussions and working group sessions, and detailed appendices including summaries of active research projects led by the workshop participants throughout the region.  It includes identification of key knowledge gaps in the region, and practical recommendations for future research and follow-up networking between participants and a wider forum of colleagues dealing with similar challenges.

To view or download the workshop report click here:

Vaquita in decline

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

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:

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