Inter-Research > ESR > v48 > p225-234  
Endangered Species Research

via Mailchimp

ESR 48:225-234 (2022)  -  DOI:

More vaquita porpoises survive than expected

Lorenzo Rojas-Bracho1, Barbara Taylor2,*, Cormac Booth3, Len Thomas4, Armando Jaramillo-Legorreta5, Edwyna Nieto-García5, Gustavo Cárdenas Hinojosa5, Jay Barlow2, Sarah L. Mesnick2, Tim Gerrodette2, Paula Olson2, Annette Henry2, Henoch Rizo6, Eva Hidalgo-Pla7, Andrea Bonilla-Garzón8

1PNUD/Sinergiaen en la Comisión Nacional de Áreas Naturales Protegidas, Ensenada, BC, México
2Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
3SMRU Consulting, St Andrews, Fife KY16 8LB, UK
4Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, Fife KY16 9LZ, UK
5Comisión Natural de Áreas Naturales Protegidas, Ensenada, BC, México
6Museo de la Ballena y Ciencias del Mar, La Paz, BC 23000, México
7Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92037, USA
8K. Lisa Yang Center for Conservation Bioacoustics, Ithaca, NY 14850, USA
*Corresponding author:

ABSTRACT: In 2018, it was estimated that fewer than 20 of Mexico’s endemic vaquita porpoise Phocoena sinus remained, and the species was declining by 47% yr-1. Entanglement in gillnets is the sole threat to the species, and since the last population size estimate, gillnetting has increased in the small area where most vaquitas remain—a 12 × 24 km area in the Gulf of California near San Felipe, Mexico. We conducted research efforts in 2019 and 2021 in that area to estimate the minimum numbers of adults and calves and look for any signs that vaquitas are unhealthy. Through expert elicitation, we estimated between 7 and 15 unique individuals were seen in 2019 and 5-13 were seen in 2021. Calves were seen in both years, and all vaquitas appeared healthy. Population projections from the last full survey indicated that more vaquitas have survived than expected. We suggest that these surviving adult vaquitas may have learned to avoid entanglement in gillnets. These vaquitas and their calves provide hope that the species can survive. However, given the high levels of illegal gillnetting and the theft of equipment which hindered our monitoring efforts, and with only around 10 individuals remaining, survival can only be assured if vaquita habitat is made gillnet-free.

KEY WORDS: Phocoena sinus · Vaquita · Conservation · Endangered species · Behavioral selection · Monitoring small populations · Expert elicitation · Illegal fishing · Porpoise

Full text in pdf format
Supplementary material 
Cite this article as: Rojas-Bracho L, Taylor B, Booth C, Thomas L and others (2022) More vaquita porpoises survive than expected. Endang Species Res 48:225-234.

Export citation
RSS - Facebook - - linkedIn