More vaquita porpoises survive than expected

被引:14
|
作者
Rojas-Bracho, Lorenzo [1 ]
Taylor, Barbara [2 ]
Booth, Cormac [3 ]
Thomas, Len [4 ]
Jaramillo-Legorreta, Armando [5 ]
Nieto-Garcia, Edwyna [5 ]
Cardenas Hinojosa, Gustavo [5 ]
Barlow, Jay [2 ]
Mesnick, Sarah L. [2 ]
Gerrodette, Tim [2 ]
Olson, Paula [2 ]
Henry, Annette [2 ]
Rizo, Henoch [6 ]
Hidalgo-Pla, Eva [7 ]
Bonilla-Garzon, Andrea [8 ]
机构
[1] Comis Nacl Areas Nat Protegidas, PNUD Sinergiaen, Ensenada, Baja California, Mexico
[2] NOAA, Southwest Fisheries Sci Ctr, Natl Marine Fisheries Serv, La Jolla, CA 92037 USA
[3] SMRU Consulting, St Andrews KY16 8LB, Fife, Scotland
[4] Univ St Andrews, Ctr Res Ecol & Environm Modelling, St Andrews KY16 9LZ, Fife, Scotland
[5] Comis Nat Areas Nat Protegidas, Ensenada, Baja California, Mexico
[6] Museo Ballena & Ciencias Mar, La Paz 23000, BC, Mexico
[7] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92037 USA
[8] K Lisa Yang Ctr Conservat Bioacoust, Ithaca, NY 14850 USA
关键词
Phocoena sinus; Vaquita; Conservation; Endangered species; Behavioral selection; Monitoring small populations; Expert elicitation; Illegal fishing; Porpoise; INBREEDING DEPRESSION; CONSERVATION; EXTINCTION; CETACEAN; DECLINE;
D O I
10.3354/esr01197
中图分类号
X176 [生物多样性保护];
学科分类号
090705 ;
摘要
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 x 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.
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页码:225 / 234
页数:10
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