An Update: Monitoring the Endangered Vaquita
- Nov. 11, 2008
- Author: Peggy Turk-Boyer, Executive Director, CEDO

* Before you read the update listen to vaquita "clicks," to find out what vaquita sound like.

 Vaquita Hotspot, 6-28-2008

The vaquita sounds were recorded on a CPOD on June 26, 2008, courtesy of Nick Tregenza and NOAA's Southwest Fisheries Science Center. The clicks occur in clusters at a rate of 20 or more clicks per second.  The individual clicks are slowed down to be audible to the human ear, but the timing between clicks is approximately correct. Sounds produced by Japanese Fisheries Research Agency.

Research is underway to test sensitive acoustic techniques that may help monitor changes in the endangered vaquita population numbers.  Researchers from Mexico’s National Institute of Ecology (INE) and the U.S. National Oceanic and Atmospheric Administration (NOAA) are now offshore of San Felipe, Baja California, where the vaquita population is concentrated, conducting research that may give us the needed tools to measure population size.

Research to help detect the vaquita, a porpoise that normally shies away from boats , began September 17, 2008 with the launching of the Vaquita Express. This  Corsair 24 sail boat is testing two types of hydrophones that are being towed as it moves, one which not only detects, but also locates the porpoise. With funding from Pacific Life, CEDO coordinated  some of the logistics of this research effort with acoustic specialists from Japan and England.       

Like all marine mammals, the vaquita uses sonar to help locate its prey and navigate in murky coastal waters, where it is found. Each species produces sound with its own unique frequency and pattern. The acoustic gear can only detect the vaquita’s “quiet voice” within 300 meters. 

The fall 2008 research expedition involves another boat, the Koipai, which has been conducting acoustic monitoring for vaquita with stationary hydrophones since 1996.  Researchers  Dr. Armando Jaramillo and Dr. Lorenzo Rojas of CICESE and INE, measured a 70% decline in acoustical sightings of the vaquita population from 1996 to 2007.  This decline has motivated the current concern about the critical status of the vaquita.

A third boat, the NOAA research vessel David Starr Jordan, is focused on repeating the direct observations technique used in 1997 to estimate the size of the vaquita population. With a high platform, gigantic binoculars and a team of porpoise specialists, the crew is doing line transects in the area where vaquita are found. Since the vaquita is shy, and doesn’t expose much of its body when it surfaces to breathe, they are hard to see, especially during rough seas. With a dwindling population size, it is hard to detect very small changes in the vaquita population with this method. Data obtained in fall 2008, will be compared with results from the acoustic monitoring to calibrate the new techniques.  To learn more about each of these research efforts, visit NOAA’s website.

Whale Trackers is an organization that films documentaries throughout the world’s oceans to explore the lives of whales, dolphins and porpoises. They are currently documenting the vaquita study. Visit Whale Trackers for up-to-date blogs and information on the current vaquita population expedition.

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