Vaquita Expedition 2008: Survey Overview

Vaquita Autonomous Acoustic Monitoring Development Cruise

Spanish (Español)


 Artwork by Barbara L. Taylor

The vaquita, or Gulf of California harbor porpoise, is the most critically endangered species of any porpoise, dolphin or whale species in the world. It is currently estimated that only around 60 individuals remain and the number is declining due to entanglement in artisanal fishing gear. The government of Mexico is currently developing a plan to remove entangling nets from the vaquita’s range, compensate fishermen with alternative livelihood options, and enforce net removal. The impact of these activities on local fishing communities will be significant and because of this, a critical part of the conservation plan is to monitor the vaquita population over time.

Acoustic methods have been identified as the best monitoring strategy because vaquita are difficult to detect visually (group size is small, they avoid ships, they spend little time at the surface). Unfortunately, currently used acoustic methods are not adequate to monitor a species as rare as vaquita. Mexico’s Instituto Nacional de Ecología (INE) has therefore requested collaborative support from the international scientific community, NOAA Fisheries included, to develop new autonomous acoustic monitoring methods.

In response to this invitation, US and Mexican scientists together with expert acousticians from Great Britain, the United States and Japan conducted a research cruise in the fall of 2008. Three research vessels were used: the Koipai Yú-Xá (MX), NOAA Ship David Starr Jordan (U.S.), and the Vaquita Express, a chartered 24' trimaran (see Vaquita Video, Photos and Recordings from the cruise).

The objectives of the cruise were to develop, test, and calibrate an acoustic monitoring system that:
• can be deployed and maintained from a small vessel;
• can gather data that can be compared through time for a minimum of 10 years into the future;
• can cover a sufficient part of vaquita range to reliably detect trends in abundance with the
objective of being able to detect a 4%/year increase as “positive growth” within a 10 year
period (this is a 50% population increase if maximum growth rates occur); and,
• can withstand strong currents and trawling activity.

US Chief Scientist: Barbara L. Taylor, PhD
Mexico Chief Scientist: Lorenzo Rojas-Bracho

Survey Coordinator: Annette Henry