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| Artwork by Barbara Taylor |
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Vaquitas are a critically endangered porpoise found only in a small part of the Upper Gulf of California, Mexico. Vaquita are the smallest porpoise and have the smallest distribution of any marine mammal. Recent acoustic data indicating a strong decline in vaquita numbers prompted the government of Mexico to take unprecedented steps to save their porpoise from extinction resulting from accidental deaths when animals drown in fishing nets that are set for fish and shrimp. The 2-year ban on gillnets within the distribution of vaquitas was announced by President Peña Nieto in April of 2015. This survey will obtain the most precise abundance estimate of vaquitas possible at the beginning of the ban period.
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R/V Ocean Starr owned by Stabbert Maritime (Photo SEMARNAT) |
The Vaquita Expedition 2015 will take place from September 26 to December 3. Chief Scientists for the survey are Lorenzo Rojas-Bracho (from Mexico’s Department of Environment and Natural Resources, SEMARNAT) and Barbara Taylor (from Southwest Fisheries Science Center, NOAA Fisheries); the survey is being supported by SEMARNAT. Both visual and acoustic methods are required to obtain a precise abundance estimate. The entire distribution of vaquitas between 20 and 50 meters deep will be visually surveyed from a research ship (the R/V Ocean Starr) using 6 huge binoculars called ‘big eyes’. These 25-power binoculars are needed to see the shy vaquita before they react to the ship. Scientists came from Mexico, the US, United Kingdom and Germany to provide porpoise sighting expertise.
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Armando Jaramillo and Gustavo Cárdenas prepare to launch CPOD. (Photo Barbara Taylor) |
Mexico is a world leader in acoustic monitoring of porpoises using a passive acoustic device called a CPOD. Armando Jaramillo-Legorreta and his team will deploy 134 CPODs in a grid in the shallow water vaquita distribution where the ship cannot go. The CPODs detect the very high frequency clicks that vaquitas use to find fish in the productive, muddy waters. Developing the acoustic monitoring system was the primary objective of the last vaquita survey in 2008. The system was designed to detect the hoped for 4%/year recovery of vaquita. Instead, the system detected a dramatic 67% decline between 2011 and 2014.
The project is a research collaboration between SEMARNAT and the Southwest Fisheries Science Center, NOAA Fisheries. Additional support is provided from Instituto Nacional de Ecología y Cambio Climático (INECC), Comisión Nacional de Áreas Naturales Protecion (CONAMP), Comisión Nacional para el Conocimiento y uso de la Biodiversidad (CONABIO), and The Marine Mammal Center.
Mexico Chief Scientist:
Lorenzo Rojas-Bracho, PhD
US Chief Scientist:
Barbara L. Taylor, PhD