Update on Conservation Efforts for the Vaquita

In 1997, the Government of México convened a committee of international experts (CIRVA) to advise it on methods to save its endemic porpoise, the vaquita, from extinction. CIRVA met for the fourth time, in February 2012, in Ensenada, México.

CIRVA recognized that since 2008 México established a Vaquita Refuge in the core of the vaquita’s distribution and initiated a scheme of monetary compensation to eliminate gillnetting and industrial trawling within this Refuge.  That scheme reduced, but did not eliminate, un-permitted fishing. The Government of Mexico, with significant support and funding from US government agencies and other groups, conducted a new survey of vaquita abundance, established an acoustics program to monitor population trends, and developed an alternative, “vaquita-safe” method for catching shrimp.  Never before has so much serious effort and funding been invested to protect the vaquita.  Without these efforts, vaquitas might already have reached a state where recovery would not be possible.

However, information presented at the February 2012 meeting showed that the vaquita population is still declining and now likely consists of fewer than 200 individuals.  The Vaquita Refuge protects only about half of the population and illegal gillnet fishing is still common inside the Refuge. Also, gillnets are still commonly used to catch shrimp and finfish outside the Refuge. CIRVA concluded that if the continuing decline in vaquita abundance is not halted within the next five years (by 2017), the species may be too depleted to ever recover.

Based on information presented at this meeting, CIRVA made a number of recommendations, the most important being:

  • All gillnets and other entangling nets need to be removed from the vaquita’s entire range.
  • Artisanal shrimp fishing vessels should be converted immediately from using gillnets to using small trawls.
  • Additional research is needed to develop vaquita-safe methods to fish for finfish with artisanal vessels. Spatial management measures are needed that provide access incentives for shrimp fishermen who use small trawls rather than gillnets.
  • A legal limit on the length of gillnets and the number of nets per vessel needs to be enforced for fisheries with such limits, like the shrimp fishery.
  • A legal limit on the length of gillnets and the number of nets per vessel needs to be established and enforced for all other fisheries (besides the shrimp fishery).
  • More effective enforcement of no-fishing regulations within the Vaquita Refuge is needed.
  • The boundaries of the Vaquita Refuge should be changed as described in the report.
  • The current acoustic monitoring scheme should continue for at least the first planned 5-year period so that vaquita population trends can be tracked and recovery strategies adapted accordingly.

The full report of the workshop is available here:

Mediterranean common dolphin sightings in Israel

The Mediterranean subpopulation of common dolphins Delphinus delphis, is listed as Endangered on the IUCN Redlist.  As recently as 50 years ago, in the Mediterranean waters of Israel, short-beaked common dolphins were thought to be more common than bottlenose dolphins, Tursiops truncatus[1]; a conclusion that was based mainly on stranding records.  Today, common dolphin strandings are very rare in Israel reflecting their regional decline.  However, encouraging news is that over the last few years, there have been repeated sightings of large groups (for the region i.e. 10-80 individuals) of short-beaked common dolphins in Israeli waters.  The recent sightings occurred in the southern part of the region, and some were within the waters of the Gaza strip[2]. Purse-seining in Gaza waters has declined substantially since Israel imposed a naval blockade and common dolphins may have responded to a resultant increase in prey abundance. It is hoped that cooperative research and conservation efforts will one day lead to the recognition of this region as one deserving of special conservation measures for common dolphins (and other cetaceans).

[1] Bodenheimer, F.S. 1960. Animal and man in bible lands. Collection de Travaux de l’Académie Internationale d’Histoire des Sciences, No 10. E.J. Brill, Leiden

[2] see http://seamap.env.duke.edu/dataset/819

Three new wildlife sanctuaries for Ganges River and Irrawaddy dolphins declared by the Government of Bangladesh

The Government of Bangladesh recently declared three new wildlife sanctuaries for endangered freshwater dolphins in the world’s largest mangrove ecosystem – the Sundarbans. The sanctuaries, which were officially declared on January 29, will protect two species of freshwater dolphins: the Ganges River dolphin and the Irrawaddy dolphin. Although there is no global population estimate for either species, both have disappeared from major portions of their range. However, both species occur in the Sundarbans in sufficient numbers that it may serve as a global safety net for preventing their extinction.  The three wildlife sanctuaries safeguard 19.4 mi (31.4 km) of channels with a total area of 4.1 sq mi (10.7 sq km).  The locations and sizes of the sanctuaries in the Sundarbans were determined according to a study conducted by WCS and the Bangladesh Forest Department and published in the journal Oryx in 2010. The study found that the habitat of Ganges River and Irrawaddy dolphins were clumped in waterways where human activities are most intense.

The dolphins are threatened by fatal entanglements in fishing gear, depletion of their prey from the enormous by-catch of fish and crustaceans in fine-mesh “mosquito” nets used to catch fry for shrimp farming, and increasing salinity and sedimentation caused by sea-level rise and changes in the availability of freshwater river flow.  It is hoped that the new wildlife sanctuaries in the Sundarbans will also provide protection for other threatened aquatic wildlife including the river terrapin, masked finfoot, and small-clawed otter.

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