title: Passive acoustic monitoring of the decline of Mexico's critically endangered vaquita.
abstract: The vaquita (Phocoena sinus) is the world's most endangered marine mammal with approximately 245 individuals remaining in 2008. This species of porpoise is endemic to the northern Gulf of California, Mexico, and historically the population has declined because of unsustainable bycatch in gillnets. An illegal gillnet fishery for an endangered fish, the totoaba (Totoaba macdonaldi), has recently resurged throughout the vaquita's range. The secretive but lucrative wildlife trade with China for totoaba swim bladders has probably increased vaquita bycatch mortality by an unknown amount. Precise population monitoring by visual surveys is difficult because vaquitas are inherently hard to see and have now become so rare that sighting rates are very low. However, their echolocation clicks can be identified readily on specialized acoustic detectors. Acoustic detections on an array of 46 moored detectors indicated vaquita acoustic activity declined by 80% between 2011 and 2015 in the central part of the species' range. Statistical models estimated an annual rate of decline of 34% (95% Bayesian credible interval -48% to -21%). Based on results from 2011 to 2014, the government of Mexico enacted and is enforcing an emergency 2-year ban on gillnets throughout the species' range to prevent extinction, at a cost of US$74 million to compensate fishers. Developing precise acoustic monitoring methods proved critical to exposing the severity of vaquitas' decline and emphasizes the need for continual monitoring to effectively manage critically endangered species.
authors.affiliation: Instituto Nacional de Ecología y Cambio Climático/SEMARNAT, Coordinación de Investigación y Conservación de Mamíferos Marinos, CICESE Camper 10, Carretera Ensenada-Tijuana 3918, Zona Playitas, Ensenada, B.C, 22860, México.
authors.forename: Armando
authors.initials: A
authors.lastname: Jaramillo-Legorreta
authors.affiliation: Instituto Nacional de Ecología y Cambio Climático/SEMARNAT, Coordinación de Investigación y Conservación de Mamíferos Marinos, CICESE Camper 10, Carretera Ensenada-Tijuana 3918, Zona Playitas, Ensenada, B.C, 22860, México.|Departamento de Biología de la Conservación, Centro de Investigación Científica y Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, Ensenada, Baja California, CP 22860, México.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Cardenas-Hinojosa
authors.affiliation: Instituto Nacional de Ecología y Cambio Climático/SEMARNAT, Coordinación de Investigación y Conservación de Mamíferos Marinos, CICESE Camper 10, Carretera Ensenada-Tijuana 3918, Zona Playitas, Ensenada, B.C, 22860, México.
authors.forename: Edwyna
authors.initials: E
authors.lastname: Nieto-Garcia
authors.affiliation: Instituto Nacional de Ecología y Cambio Climático/SEMARNAT, Coordinación de Investigación y Conservación de Mamíferos Marinos, CICESE Camper 10, Carretera Ensenada-Tijuana 3918, Zona Playitas, Ensenada, B.C, 22860, México.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rojas-Bracho
authors.affiliation: Alaska Fisheries Science Center, NOAA Fisheries, National Marine Mammal Laboratory, 7600 Sand Point Way N.E., Building 4, Seattle, WA, 98115, U.S.A.
authors.forename: Jay
authors.initials: J
authors.lastname: Ver Hoef
authors.affiliation: Southwest Fisheries Science Center, NOAA Fisheries, Protected Resources Division, 8901 La Jolla Shores Dr, La Jolla, CA, 92037, U.S.A.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Moore
authors.affiliation: Chelonia Limited, The Barkhouse, Mousehole, TR196PH, U.K.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Tregenza
authors.affiliation: Southwest Fisheries Science Center, NOAA Fisheries, Protected Resources Division, 8901 La Jolla Shores Dr, La Jolla, CA, 92037, U.S.A.
authors.forename: Jay
authors.initials: J
authors.lastname: Barlow
authors.affiliation: Southwest Fisheries Science Center, NOAA Fisheries, Protected Resources Division, 8901 La Jolla Shores Dr, La Jolla, CA, 92037, U.S.A.
authors.forename: Tim
authors.initials: T
authors.lastname: Gerrodette
authors.affiliation: University of St Andrews, Centre for Research into Ecological and Environmental Modelling, The Observatory, Buchanan Gardens, St Andrews, Fife KY16 9LZ, U.K.
authors.forename: Len
authors.initials: L
authors.lastname: Thomas
authors.affiliation: Southwest Fisheries Science Center, NOAA Fisheries, Protected Resources Division, 8901 La Jolla Shores Dr, La Jolla, CA, 92037, U.S.A.
authors.forename: Barbara
authors.initials: B
authors.lastname: Taylor
mesh_terms: D000162:Acoustics; D000818:Animals; D001499:Bayes Theorem; D003247:Conservation of Natural Resources; D004455:Echolocation; D056727:Endangered Species; D006801:Humans; D008800:Mexico; D019576:Porpoises
keywords: Phocoena sinus; declive poblacional; extinción; extinction; modelado estadístico; population decline; statistical modeling