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

Red List Status and Extinction Risk of the World’s Whales, Dolphins and Porpoises – New Infographic

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From 2017 to 2021, the CSG reassessed nearly all currently recognized species of cetaceans (90 of 92 at that time) for the IUCN Red List.  Regular updates regarding progress on this task, which involved many CSG members, have been provided on this website (see 2022, 2021, and 2020 updates on red listing progress).  With the task close to completion, the information contained in the newly updated Red Rist assessments was collated to provide an overview of the global Red Rist status, which was published in Conservation Biology earlier this year in a paper with the title Red List Status and Extinction Risk of the World’s Whales, Dolphins and Porpoises.

 

The key findings of the paper are shown in the bullet points below.  To aid in communication of the findings and to highlight important issues to decision makers and the public the infographic below was also developed.  This infographic is available for download and we encourage everyone to use it.

 


Key Findings

    • One in 4 cetacean species (26% of 92) were assessed as being threatened with extinction (i.e., Critically Endangered (CR), Endangered (EN), or Vulnerable (VU)) and 11% as Near Threatened (NT).
    • Ten percent of cetacean species were assessed as Data Deficient, and it was predicted that 2–3 of these species may prove to be threatened.
    • The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008 and 26% in 2021.
    • The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat.
    • Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges.
    • Cetacean that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat.
    • Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia and Papua New Guinea and into the coastal waters of China.

 

Vaquitas continue to surprise the world with their tenacity

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Article by Barbara Taylor and Lorenzo Rojas-Bracho

 

Given the 45% annual decline estimated in 2018, most people expected Mexico’s vaquita porpoise to already be extinct.  Scientists have just seen (May 2023) about the same number of vaquitas they saw in 2019 and 2021 in a small area in the far northern Gulf of California near San Felipe, Mexico (read the full report here in English and here in Spanish plus the Appendices in English only).  The visual research, including both ships and contracted professional observers, was funded by Sea Shepherd Conservation Society.  Around ten individuals, including at least one calf, were seen. All the animals looked healthy and they were feeding.  Given the precision of estimates between 2019 and 2023 no conclusion can be drawn as to whether vaquitas are increasing or decreasing.  One reason the team was able to obtain photographs and drone footage is that there was very little fishing activity in the area at the time of the survey. Intense fishing activity had interfered with survey efforts in previous years, which had always been in the autumn shrimping season.

 

In August 2022 the Mexican Navy deployed 193 concrete blocks with 3m high metal hooks designed to entangle gillnets.  Blocks were set within the vaquitas’ last stronghold: a 12 x 24 km area called the Zero Tolerance Area (ZTA).  The Navy and Sea Shepherd Conservation Society (SSCS) have collaborated to monitor fishing activity over the past 9 months.  The apparent 90%+ decrease in gillnetting within the last stronghold of vaquitas is probably the most significant step taken to date toward saving the species.  When gillnetting within the ZTA is observed, SSCS reports to the Navy and the Navy is expected to ensure that the gillnets are removed and the fishermen relocate to fish outside the ZTA. Sometimes nets are confiscated, despite the fact that all gillnets should be banned in the vaquita’s area of distribution.

 

May is a low fishing season, so the two survey ships were able to work outside the ZTA for the first time in recent years.  Acoustic research, funded by the Government of Mexico and the Cetacean Action Treasury, had already made many acoustic detections of vaquitas along the northwestern border of the ZTA (Figure 1).

Figure 1. Summary of vaquita acoustic detections during the May survey period with the days of recording depicted by the size of the dots and the color indicating the number of acoustic encounters. The small yellow dots are locations where vaquitas were seen. Clusters of yellow dots represent multiple locations of the same individuals tracked over time. The ZTA is outlined in green and the San Felipe harbor is the small square at the bottom of the figure.

This year’s survey recorded visual sightings of both vaquitas (Figure 2) and gillnetting (Figure 3) in the area.

Figure 2. Tracklines followed by Seahorse (blue lines) and Sirena de la Noche (red lines) during Vaquita Survey May 2023. The small dots are locations where vaquitas were seen: green for confirmed cow/calf locations and black for all other vaquita locations. Clusters of dots represent multiple locations of the same individuals tracked over time. The ZTA is outlined in green and San Felipe harbor is the small square at the bottom of the figure.

 

The concrete blocks together with enforcement within the ZTA seem to constitute an effective way to prevent gillnetting.  The SSCS ship has advanced side-scan sonar and has found only one net entangled on the blocks and hooks (Figure 4).  Based on this year’s results, expansion of the concrete block-and-hook approach to other areas where vaquitas are known to be feeding is an urgent priority.

 

Figure 3. Gillnetters with panga tied up to the ZTA border buoy at the northern-most corner. Their gillnets were set just outside the ZTA in the area where vaquitas were observed. Photo by Barbara Taylor.

Figure 4. Red lines show where side-scan sonar was used. The area of the ZTA is completely covered because of the focus to search for ghost nets entangled on the concrete block hooks. The yellow rectangle depicts a buffer zone used to quantify fishing effort near the ZTA. The blue line shows the boundary of the Vaquita Refuge.

 

 

 

 

Vaquitas get action from CITES as totoaba poaching resumes

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By Barbara Taylor, Lorenzo Rojas-Bracho and Kristin Nowell

On 27 March 2023 the Secretariat of the Convention on the International Trade of Endangered Species (CITES) notified signatory countries to stop all commercial trade in CITES-listed (in Appendix I or II) species from Mexico.  This decision stems from the inadequacy of actions taken by Mexico to prevent totoaba from being poached and vaquitas from being ‘collateral damage’ in the illegal gillnet fishery.  The sanctions will remain in place until Mexico submits an adequate compliance action plan.  Once approved, Mexico’s implementation of its action plan will be evaluated at the next meeting of the CITES Standing Committee in early November in Geneva to determine whether sufficient progress has been made by then. Further details are given in several news reports:

 

While gillnet fishing effort remains much lower than in the past within the Zero Tolerance Area (ZTA) (see previous CSG news posting), outside this small area there is no evidence that gillnetting has been reduced. Further, fishing with alternative vaquita-safe methods is very rare in waters near the ZTA.  Totoaba are just arriving on their annual spring migration to spawn, and recent reports indicate that they are being subjected, immediately upon arrival, to intensive poaching pressure (https://www.excelsior.com.mx/nacional/desatada-pesca-ilegal-de-totoaba-con-todo-y-sanciones-comerciales/1578081 or a machine translated English version here).

 

The Mexican Navy’s deployment of concrete blocks with entangling hooks within the ZTA, where vaquitas have spent most of their time in recent years, appears to have had a positive effect so far. The number of gillnetting pangas (small fishing boats) observed inside the ZTA has been reduced. This reduction may be due not only to the deterrence effect of the anti-gillnet devices but also to the Navy’s enforcement efforts with support from the Sea Shepherd Conservation Society (SSCS). Since vaquitas cannot survive for long in waters where gillnets are used, the species’ recovery depends on both rigorous adherence to the ZTA’s no-entry rule and ensuring that all fishing in vaquitas’ historical range in the Upper Gulf outside the ZTA is vaquita-safe.