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• Population & surveys

Results

• 2025REPORT

  Vaquita Research Campaign 2025: Report of the September Vaquita Survey

  Cárdenas-Hinojosa and co-authors · CONANP · Vaquita survey 2025

  In September 2025, scientists aboard two Sea Shepherd ships searched the northern Gulf of California for vaquitas, using underwater microphones at 66 sites to decide where to look. They most likely saw between 7 and 10 different animals, including at least one or two calves. This counts the vaquitas seen in the area they searched. It is not an estimate of how many are left in total.

  Population & surveys Acoustic monitoring

• 2024REPORT

  Reporte del crucero de observación de la vaquita 2024

  Cárdenas-Hinojosa and co-authors · CONANP (Comisión Nacional de Áreas Naturales Protegidas) · CONANP 2024

  This Spanish-language report covers the May 2024 vaquita survey, which searched the Zero Tolerance Area and a new Extension Area next to it from two ships. The team made 9 sightings and recorded 70 acoustic encounters. Expert elicitation gave a 75% probability that 6 to 8 different vaquitas were seen, and most likely no calf, though one animal of about a year old was seen.

  Population & surveys Acoustic monitoring Habitat & ecosystem In Spanish

• 2023REPORT

  Survey report for vaquita research 2023

  Jaramillo-Legorreta and co-authors · CONANP, NOAA Southwest Fisheries Science Center and Sea Shepherd Conservation Society · Vaquita survey 2023

  This report describes the vaquita survey of 10 to 26 May 2023, with 17 days of visual search from two ships in and around the Zero Tolerance Area. The team made 16 sightings and 61 acoustic encounters. Expert elicitation gave a 76% probability that between 8 and 13 vaquitas were seen, including 1 to 2 calves.

  Population & surveys Gillnets & bycatch Policy & enforcement

• 2022RESEARCH

  More vaquita porpoises survive than expected

  Rojas-Bracho and co-authors · Endangered Species Research 48: 225-234 · Peer reviewed · Rojas-Bracho et al. 2022

  The authors report visual surveys in the Zero Tolerance Area in 2019 and 2021 and used expert elicitation to judge how many different vaquitas had been seen. They concluded that between 7 and 15 unique individuals were seen in 2019 and between 5 and 13 in 2021, which is more than a projection from the 2018 estimate would predict. These are counts of animals seen in one small area, and they are not population estimates.

  Population & surveys Gillnets & bycatch Habitat & ecosystem

• 2022REPORT

  Phocoena sinus, Vaquita. The IUCN Red List of Threatened Species 2022: e.T17028A214541137

  Rojas-Bracho and co-authors · The IUCN Red List of Threatened Species 2022-1, IUCN Global Species Programme (assessment e.T17028A214541137) · IUCN Red List 2022

  This is the 2022 Red List assessment of the vaquita, which places the species in the Critically Endangered category under criteria A2a, C1+2a(ii), D and E. The assessors give a best estimate of about 10 animals in 2018, down from 567 in 1997, and name entanglement in gillnets as the threat that has not stopped. The page also records the status history, from Vulnerable in 1986 and 1988 through Endangered in 1990 and 1994 to Critically Endangered since 1996.

  Population & surveys Gillnets & bycatch Conservation efforts

• 2022RESEARCH

  The critically endangered vaquita is not doomed to extinction by inbreeding depression

  Robinson and co-authors · Science 376(6593):635-639 · Peer reviewed · Robinson et al. 2022

  The authors sequenced whole genomes from 20 vaquitas and used them to build simulations of recovery. They found that the species' long history of being rare left few harmful gene variants that inbreeding could expose, so low genetic diversity should not by itself prevent recovery. In the simulations, the outcome depends on how much gillnet mortality is cut, with 6% of runs going extinct within 50 years if bycatch stops, 27% with a 90% cut and 62% with an 80% cut.

  Population & surveys Gillnets & bycatch Conservation efforts

• 2019RESEARCH

  Decline towards extinction of Mexico's vaquita porpoise (Phocoena sinus)

  Jaramillo-Legorreta and co-authors · Royal Society Open Science 6(7): 190598 · Peer reviewed · Jaramillo-Legorreta et al. 2019

  This paper gives the last estimate of the whole vaquita population, for 2018, about 9 animals (95% credible interval 6 to 19). It combines eight years of acoustic monitoring (2011 to 2018) with the 2015 survey estimate and with minimum counts of animals seen in 2017 and 2018. The authors also revise the 2015 estimate upward, from a posterior mean of about 60 to 100.

  Population & surveys Acoustic monitoring Gillnets & bycatch

• 2017RESEARCH

  Last call: Passive acoustic monitoring shows continued rapid decline of critically endangered vaquita

  Thomas and co-authors · The Journal of the Acoustical Society of America 142(5):EL512-EL517 (JASA Express Letters) · Peer reviewed · Thomas et al. 2017

  A grid of underwater click recorders has been run in the vaquita refuge for about three months each year since 2011, and this paper reports the 2016 results. Acoustic detections fell by 49% between 2015 and 2016 (95% credible interval, 82% decline to 8% increase), and by more than 90% overall between 2011 and 2016. Assuming detections track population size, about 30 vaquitas (95% credible interval 8 to 96) remained in November 2016.

  Population & surveys Acoustic monitoring

• 2016RESEARCH

  Extinction is Imminent for Mexico's Endemic Porpoise Unless Fishery Bycatch is Eliminated

  Taylor and co-authors · Conservation Letters 10(5):588-595 · Peer reviewed · Taylor et al. 2016

  The authors combined a ship-based visual line-transect survey with an array of underwater click detectors (C-PODs), run at the same time in autumn 2015, to estimate how many vaquitas were left across the species' whole range. They estimated 59 vaquitas (median of the posterior distribution, 95% Bayesian credible interval 22 to 145), a decrease of 92% since 1997 (95% credible interval 80 to 97%). They also projected the population forward under two scenarios, one with the gillnet ban kept and enforced and one with a return to the 2011-2015 rate of decline.

  Population & surveys Acoustic monitoring Gillnets & bycatch

• 2011RESEARCH

  A combined visual and acoustic estimate of 2008 abundance, and change in abundance since 1997, for the vaquita, Phocoena sinus

  Gerrodette and co-authors · Marine Mammal Science 27(2):E79-E100 · Peer reviewed · Gerrodette et al. 2011

  A line-transect survey in October and November 2008 combined visual searching from a large research vessel with an acoustic array towed by a sailboat in the shallowest areas. It estimated 245 vaquitas (95% CI 68 to 884), which is 57% lower than the 1997 estimate of 567. The authors found an 89% probability that the total population declined between the two surveys.

  Population & surveys Acoustic monitoring

• 2011RESEARCH

  Estimating the success of protected areas for the vaquita, Phocoena sinus

  Gerrodette and Rojas-Bracho · Marine Mammal Science 27(2):E101-E125 · Peer reviewed · Gerrodette & Rojas-Bracho 2011

  The paper fits a Bayesian population model to data on abundance, bycatch and fishing effort to estimate the chance that each of three proposed gillnet closures, set out in Mexico's 2008 conservation plan, would let the vaquita population grow over ten years. The existing Refuge Area had a probability of success of 0.08, a larger second option 0.35, and a third option covering the whole range more than 0.99. The model estimates the population fell from 664 in 1993 to 209 in 2009.

  Population & surveys Gillnets & bycatch Conservation efforts

• 1999RESEARCH

  A new abundance estimate for vaquitas: first step for recovery

  Jaramillo-Legorreta and co-authors · Marine Mammal Science 15(4):957-973 · Peer reviewed · Jaramillo-Legorreta et al. 1999

  A three-boat line-transect survey in summer 1997 was the first designed to estimate vaquita abundance over the whole range. It recorded 125 sightings of vaquita groups and estimated a total population of 567 animals (95% CI 177 to 1,073). The authors say this is better than earlier estimates, but that it should not be compared directly with the 1993 figure.

  Population & surveys

• 1997RESEARCH

  First estimates of vaquita abundance

  Barlow and co-authors · Marine Mammal Science 13(1):44-55 · Peer reviewed · Barlow et al. 1997

  This paper gives the first abundance estimates for the vaquita, drawn from four boat, aerial and ship surveys carried out in Mexico between 1986 and 1993. The four estimates range from 224 to 885 animals and are all very imprecise, because the surveys had few sightings and borrowed some inputs from the harbour porpoise. The authors concluded that every estimate put the species at a critically low level.

  Population & surveys