Vaquitas seen in autumn 2021 survey

From October 17 through November 3, 2021, a vaquita research effort was privately funded through the Museo de la Ballena y Ciencias del Mar and a number of private donors.  The survey focused on the last stronghold of vaquitas, the Zero Tolerance Area (ZTA) declared in Mexico’s Federal Register of September 24, 2020 as an area defined as follows: Fishing activities of any kind, with any type of vessel, including sport fishing, are permanently and totally prohibited within the “Zero Tolerance Area”. No type of vessel will be allowed to transit or navigate in this area, unless the vessel is authorized to transit, in writing, by the competent authority.


Both vaquitas and large amounts of illegal gillnetting were observed during the survey. The 2021 survey report (available here) documents the study in 2021 that was designed to be as close as possible to the research last conducted in 2019.  In the intervening 2 years, net removal coverage was limited in 2020 (see news reports on this website 1, 2, 3) and after January 1, 2021 only the Mexican Navy carried out actions for the removal of nets with no participation by the Sea Shepherd Conservation Society and Museo de la Ballena because strong civil unrest had resulted in the Navy telling the net-removal ships to leave the area.  In the absence of a strong programme to support and incentivize the deployment of alternative fishing gear, fishing communities have continued using gillnets for shrimp and finfish including totoaba.


As was the case in 2019, the survey was hindered by the large number of gillnets and pangas, which was documented from the Museo de la Ballena’s ship the Narval in the 2019 Report with 87 and in the 2021 Report with 117 pangas within the ZTA.  As specified in the Memorandum of Understanding between the Sea Shepherd Conservation Society and the Government of Mexico, details on illegal gillnetting were recorded multiple times each survey day and the data were turned over to the Government of Mexico.  One apparent enforcement action was witnessed during the survey.


As a consequence of unfavorable weather conditions, no photographs of sufficient quality to identify individual vaquitas were obtained, which made estimation of the number of vaquitas within the ZTA using mark-recapture methods impossible.  Instead, a method called Expert Elicitation was used as was done in 2019.  The 2019 report concluded that the most likely number seen in the ZTA was about 11 individuals including 3 calves (2019 Report here).  The 2021 report found that the most likely number seen in the ZTA was about 7 or 8 individuals including 1 or 2 calves (2021 Final Report here).  Given the concentration of fishing within the vaquita’s last 12 x 24km stronghold and the lack of any effort to deter gillnetting within the ZTA over the two-year period, the survival of these individuals is nothing short of remarkable.


Letter sent from IUCN SSC regarding strengthening protection measures for the vaquita

On 14th August 2021, the Chair of the IUCN Species Survival Commission, Jon Paul Rodríguez sent a letter to members of the Government of Mexico, the Government of the US, Government of Canada, the Trilateral Commission for Environmental Cooperation, Government of China, European Union, CITES Secretariat, World Heritage Center and the Global Environment Facility requesting immediate actions from governments, international bodies and potential donors to help to save the vaquita.


The letter explained that the most urgent is the need for technical, financial and legal support to the Mexican government and civil society to ensure effective implementation of conservation actions: scientific vaquita monitoring, equipping and training local fisherfolk to use legally mandated gear, continual removal of illegal gillnets from vaquita habitat, and training and increased resources for law enforcement.  It also urged the Grupo Intergubernamental sobre la Sustentabilidad en el Alto Golfo de California to modify the so‐called “Trigger Factors” agreement published 9 July 2021, which is a complex fisheries management program that will be almost impossible to implement and enforce and which undermines the legal commitment to Zero Tolerance in the very small (280 km2) area where the last few vaquitas remain.


The letter can be read in full here.

New estimate of vaquita status improved through elicitation of expert knowledge

A vaquita being tracked within the Zero Tolerance Area and a panga with a buoy for a set gillnet in the background on 17th October 2019. Credit. Todd Pusser. 


The results of a virtual workshop to use expert elicitation to better estimate the number of vaquitas seen in the Zero Tolerance Area are now available here (Final Vaquita Expert Elicitation Report).  Since 2019 acoustic monitoring to assess trends in abundance of the vaquita has not been possible because so much equipment has been stolen.  With so few vaquitas remaining, a two-ship effort in October 2019 was launched in the hope of obtaining sufficient photographically identified vaquita individuals to use mark-recapture methods to estimate vaquita numbers.  Although there were 7 encounters with vaquita groups, surviving vaquitas are so wary and hard to approach that insufficient numbers of high-quality photographs were obtained for the analysis. Therefore, a new approach was adopted, utilizing expert elicitation to obtain the best available estimate of the number of vaquitas seen.  A workshop was held in August, 2020 and included all observers who participated in the vessel-based field survey in October 2019, and was led by researchers at St. Andrews University.  The results of the expert elicitation exercise found the mean estimate for the number of vaquita calves seen was 3 with a 63% belief that there were at least 3 calves.  The mean estimate for the number of unique vaquitas seen in all 7 sightings was 9.4 with a 40% belief that there were at least 10.  Also of note was that tracking vaquitas was difficult because the ships and pangas had to maneuver around illegal fishers with gillnets set.

A female vaquita and her calf next to a panga with a gillnet being set within the Zero Tolerance Area on 17th October 2019. Credit: Museo de la Ballena