First vaquita found dead in 2018 – March 2018 Update

On March 27 the Mexican Navy recovered a decomposed vaquita. A necropsy was conducted on April 4 and it was confirmed that the animal died from entanglement (see Necropsy Report).

The net removal effort continues

Bags of net and anchors being taken from the net removal program

With fewer than 30 vaquitas remaining and the idea of rescuing some by capturing them and placing them in a managed enclosure not considered viable, conservation action is now focused on enforcement and net removal.

The current enhanced net removal effort during the totoaba spawning season will last until May 2018. Because the net removal effort is critical to saving the vaquita, progress is updated on this website monthly (see previous updates for Feb and Jan here).

The map (Source: Siegenthaler, N. 2018. Sea Shepherd Conservation Society Internal Reports) shows active nets removed from December 2017-March 2018 by all net removal operations. The yellow dots are active totoaba nets removed prior to March and the black dots those removed during March only. The black line denotes the Vaquita Refuge and the orange line the enhanced enforcement area.

The table below shows the number of totoaba nets removed, by ship, during the totoaba spawning season. JPD stands for the ship Jean Paul Dejoria, which was replaced by the Sharpie in March. The Narval belongs to the Museo de Ballena of La Paz and the other ships to the Sea Shepherd Conservation Society. “na” stands for ‘not applicable’ since the ships did not operate in that month.

December January February March Total
Narval na 2 36 20 58
Farley Mowat 2 0 9 44 55
JPD 16 28 51 5 100
Sharpie na na na 35 35
Total 18 30 96 104 248

Patricia Gandolfo campaign leader of Sea Shepherd’s Operation Milagro standing next to 24 dead totoabas pulled from a single net

Despite focusing the enhanced net removal efforts and enforcement in areas of overlap between vaquita distribution and illegal fishing activity, the removal of active totoaba nets is apparently following the pattern of the last two years, which has resulted in the continuing dramatic decline in vaquita numbers.  Direct comparisons of the number of nets removed by Sea Shepherd efforts in different years are not valid because the nature of the effort has been evolving (details in this Report by visiting CIRVA members). The searching efficiency of the net retrieval vessels has increased due to the use of sonar, while the illegal fishermen have become better at avoiding net retrieval by spotting search activities and setting their nets at times and in places where they are less likely to be discovered.  However, the data in the table and figure clearly indicate that illegal fishing persists.  So far, there is no indication that enhanced enforcement is being effective.

Posted in Critically Endangered, entanglements, Vaquita | 1 Comment

Vaquita peril persists with on-going illegal totoaba fishing – February 2018 Update

The net removal effort, started by Sea Shepherd’s Operation Milagro in collaboration with the Mexican Navy in 2015, is building to become the biggest yet in the totoaba season currently under way. The initial Sea Shepherd/Navy effort focused on observing pangas illegally setting nets at night and on removing those nets. The effort was expanded in 2016 to systematically remove both active and inactive nets throughout the vaquita’s primary distribution.  This expansion in effort has been led by the Department of the Environment (SEMARNAT) together with Sea Shepherd, the Mexican Navy and Army, PEMEX, WWF-Mexico, Museo de la Ballena, Parley, World Animal Protection, and the fishermen’s organizations PESCA ABC and Cooperativa Islas del Golfo. The Mexican Fisheries Department CONAPESCA recently started supporting the program as well.

From December, 2016, through February, 2018, SSCS has retrieved 394 nets, over 270 of which have been active totoaba nets. A total of 61 totoaba nets were retrieved in February 2018. This takes the total number of active nets removed by Sea Shepherd thus far in 2018 to 96. Over 50 tons of net were donated to Parley for recycling (further details can be found in the CIRVA 10 Report).With fewer than 30 vaquitas remaining and the idea of rescuing some by capturing them and placing them in human care not considered viable, conservation action is now focussed on enforcement and net removal. The current net removal effort during the totoaba spawning season will last until May. Because this effort is critical to saving the vaquita, progress will be updated on this website monthly.

Despite the enhanced net removal efforts and enforcement focus on areas of overlap between vaquita distribution and illegal fishing, the removal of active totoaba nets is apparently following the pattern of the last two years, which has resulted in the dramatic decline in vaquitas. To give the best idea of the relative risk of entanglement for vaquitas, only efforts by Sea Shepherd in the past 2 years are shown. Even then direct comparison of the numbers of nets removed by Sea Shepherd efforts in February 2017 and 2018 is not a perfect indicator of the risk presented to vaquitas because net removal has become more efficient both due to experience and increased efficiency resulting from the addition of using side-scan sonar to locate nets. However, the data in the table and figure below clearly indicate that illegal fishing persists and follows the earlier pattern of increasing as the totoaba spawning season progresses. So far, there is no indication that enhanced enforcement is being effective.

The map shows active nets removed from December 2017-February 2018. The yellow dots are active totoaba nets removed prior to February and the black dots those removed during February only. The black line denotes the vaquita refuge and the orange line the enhanced enforcement area.

The bar graph shows the number of totoaba nets removed by Sea Shepherd during totoaba spawning season for the Milagro III operation (blue) and through February for Milagro IV (orange).

Source: Siegenthaler, N. 2018. Sea Shepherd Conservation Society Internal Reports

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Insights into Critically Endangered Mekong Dolphin Genetics and What This Means for Conservation

New research has shed light on the genetics of critically endangered Irrawaddy dolphins in the Mekong River. The results are interesting, concerning, hopeful, and a call to action. The study brought together samples collected between 2000 and 2009 and the work of a group of researchers, to look at the genetic diversity, phylogeny, and demographic history of the Mekong dolphin population, and consider what this means for conservation.

The genetic diversity of the population is low, though the results weren’t clear whether this was due to (i) recent genetic collapse from the currently small population size or (ii) the low diversity inherited from the Irrawaddy dolphins that first moved into the Mekong River long ago (with such a long life-span, dolphins evolve slowly). However the results were clear that Mekong dolphins are very distinct from other Irrawaddy dolphins, even those in nearby coastal areas in Cambodia. It’s possible that the population represents a sub-species, though more evidence is needed to clarify this.

Fig 1 – Phylogenetic relationships of the genus Orcaella based on 384bp of the hyper-variable region I of mitochondrial DNA. Numbers indicate Bayesian posterior probability values for each clade.

So what does this mean for conservation of dolphins in the Mekong? Preserving the existing genetic diversity is a high priority, and the best way to do this is by protection of the existing wild population. Ongoing work in the field to protect them through management of gillnet fishing in dolphin habitats and parallel awareness raising and livelihood diversification work with local communities is the cornerstone. These efforts need to be combined with continuing policy support to protect remaining dolphin habitat from developments like proposed mainstream hydropower dams.

See our Special Projects page for more information on the Critically Endangered population of Irrawaddy dolphins in the Mekong River.

The full article:

Krützen, M, Beasley I, Ackermann, CY, Lieckfeldt, D, Ludwig, A, Ryan GE, Bejder, L, Parra, GJ, Wolfensberger, R, & Spencer, PBS (2018). Demographic collapse and low genetic diversity of the Irrawaddy dolphin population inhabiting the Mekong River. PLoS ONE 13(1): e0189200

Posted in Critically Endangered, entanglements, Freshwater Dolphins, Mekong dolphins | Leave a comment