Action Sheet

  • Location :
    Sea of ​​Cortez, Mexico
  • Species status :
    Seriously threatened by the IUCN
  • Period :
    January 2010 - December 2012


Field operator

The vaquita is the most endangered cetacean in the world.

Females have an average length of 140.6cm and males tend to be somewhat smaller. It is a naturally rare species and is the only Mexican endemic marine mammal. The species has remained unknown to science until the second half of the last century.

In 1997, the population was estimated at about 600 individuals but today the vaquita population is limited to only about 150 individuals. This reduction has mainly been caused by an increase in fishing activity.

Ten years worth of research data on the vaquita made the Mexican government in 2007 put forward the first necessary measures to restore the species´ populations.The government implemented a program to encourage fishermen to change their economic activities.  Monitoring activities were intensified in order to avoid the use of gill nets in the vaquita refuge areas. All this led to a 40% reduction in fishing activity in the region.  Unfortunately more information is needed to develop effective conservation actions to protect the species. The current measures are still insufficient to detect small population changes. In 2008, the Mexican government pledged to reduce by-catch to zero within three years.

The project leaders are Dr. Lorenzo Rojas Bracho and Dr. Armando Martín Jaramillo:

  • Dr. Rojas has participated since 1999 in marine mammal research programs at the Autonomous University of Baja California (UABC). He is now head of the Marine Mammal Research and Conservation Group at the Mexican National Institute of Ecology and is a member of the International Whaling Commission (IWC) as well as of the IUCN Cetacean Specialist Group.
  • Dr. Armando Martin Jaramillo is a biologist specialized in coastal oceanography.  He is responsible for analyzing and evaluating the data obtained during the 2008 campaign with the objective of estimating the size of the vaquita population. He is presently part of the national marine mammal research and conservation program of the National Ecology Institute in Mexico.

Field operator

Project holders:

The Cousteau Society (Paris)


Francine COUSTEAU -The Cousteau Society


  • To understand: Through our ship Alcyone’s expeditions to the most sensitive regions of the planet, throughmovies, books and publications, multimedia technology, conferences and advocacy in international media and meetings as reported in news, through educational programs with Echotechnie chairs at the university level and with Cousteau Kids  in the classroom for children.
  • To love: Through the link between members of the US- and France-based organizations and through the network of Cousteau Schools. Love for the environment entails diagnosing its needs and tending to it, which come at a price. To maintain their independence, The Cousteau Society and Cousteau Society accept no government subsidies
  • To protect: Through the Cousteau Label program for integrated development of the world’s coastal regions, through the petition for an International Court of the Environment and through encouraging potential antagonists to request arbitration of their conflicts by the Permanent Court of Arbitration of The Hague, so that the rights of future genereations may be preserved.


The main objective of this project is to determine the vaquita population´s present and future trends, through the development of an autonomous acoustic detector network.

The vaquita emits high frequency sounds, which are specific to the species and therefore could be considered to be a type of “identity card” for the latter. This acoustic network will permit the collection of data over several months in order to enable the detection of even small population fluctuation changes. This system is most efficient and cost effective as the boat trips would only be carried out to retrieve the data from the detectors. The acoustic sensor network will:

  • improve population abundance estimates
  • determine the population trends, the threats posed on the species.
  • understand the history of these populations
  • provide decision makers with critical information regarding the risks and potential scenarios for the species

The information that has been collected over the years shows that it is still possible to protect the vaquita and its habitat. It is therefore urgent to:

1. Test the acoustic detector deployment system using dummy sensors to determine their resistance to the potential negative oceanographic conditions and to the possibility of theft.
2. Test the reliability of the acoustic data.
3. Obtain more data and measure the different parameters associated to the vaquita´s acoustic behavior.
4. Get more information concerning the vaquita´s demographic trends from the data provided by the acoustic detector technique.


The base camp for the vaquita fieldwork is San Felipe, a fishing port very close to the vaquita distribution area.

The current methods for obtaining acoustic data are based on visual observation and active acoustic detection, but have proven to be insufficient in detecting population abundance changes of the vaquita when numbers are so low. Therefore, the establishment of a system of acoustic detectors will provide the essential information for the conservation of the species.

Development of the mooring systems

The first step in the vaquita project is to develop the appropriate mooring systems. Two mooring system are planned;

1. The first type is based on a submarine model, not visible at the surface. The advantage of this system is that possible events of theft were avoided.
2. The second is visible at the water surface, and is based on the use of buoys. The advantage of this system is that the devices can be easily located and data consequently obtained.

Expert engineers will be consulted to develop prototypes of these two systems, which will be tested in different oceanographic and meteorological conditions.

The buoys will be left in the sample area to test their effectiveness. One advantage of using buoys is that they have already been tested under the worst weather conditions.

Expected Results:

- The evaluation of the mooring systems to decide which prototype is the most effective

Establishment of the acoustic detector network

The prototype sensors will be used at different times to assess the reliability of the acoustic information. The tests will begin n in spring-summer 2010 and a report of the collected data will be prepared at the end of 2010. The implementation of the operational acoustic network will begin from August 2010 in the vaquita refuge area. A steering committee bringing together the different scientific experts will monitor and analyze the results of the pilot study and make preliminary recommendations before deploying the final system in the period of spring-winter of 2011.

Expected Results:

- The evaluation of detector prototypes for the deployment of the final acoustic network.

Results 2010

The beginning of the mooring/anchoring tests that was planned for early April was delayed by one week due to an earthquake measuring 7.2 on the Richter scale, which shook the state of Baja California. The access roads to the vaquita distribution area were damaged. Luckily the effects of the earthquake at Ensenada at the sit of the research laboratory were low.

In April, shortly after having implemented the first trials at sea the research team was not able find one of the two mooring systems. The location of the mooring systems using GPS was therefore shown to be ineffective to recover the mooring systems. Since these initial trials, the research team hopes to achieve better results by improving the current system, to try to retrieve the lost mooring system.

Dr. Rojas and Dr. Martin Jaramillo attended the International Whaling Commission (IWC) meeting held between June 21st to June 25th 2011 at Agadir and the conservation of the vaquita was again discussed by the scientific committee. The committee presented its gratitude to the various sponsors and teams working on the development of the autonomous detector vaquita monitoring. The committee also strongly encouraged Mexico to continue and intensify its efforts to conserve vaquitas and stressed that the vaquita case study would serve as a future reference  for other  countries  with similar bycatch problems.

The pilot study finally began after having tested the mooring systems at sea. Two C-PODs (acoustic sensors) were installed on the already implemented mooring systems. After this trial period, the first vaquita detections could be made! The data collected were analyzed and  sent to Nick Tregenza (the designer of the C-POD) for evaluation. These data will also be used to make the first calculations of “acoustic density”, which will be used to confirm the necessary efforts to estimate population trends of the population


- In August, 2012 -

Mission in Mexico

The President of the The Explorers Foundation, Bernard Limal, went to the west coast of Mexico last August in order to meet the scientists in charge of the Vaquita conservation project and to assess its operation. He was warmly welcomed by the team of the research centre in Ensenada, who presented the updates of the project and brought him to a field survey on boat to check the buoys in the Vaquita refuge area, within the Cortez Sea. These buoys are used for Vaquita acoustic monitoring. Indeed, the specie is really hard to observe because of its rareness, its small size, its shy behaviour and the opacity of the water coming from the Colorado Delta. An additional day was dedicated to the meeting with local fishermen and the protected areas representatives in order to discuss about common measures for Vaquita management.

This encounter with local stakeholders and Mexican authorities encouraged a positive dynamic to protect the most endangered cetacean in the world.

Picture of the participants of the meeting with fishermen (© B. Limal, The Explorers Foundation)

- In March, 2012 –

Interesting results for the Vaquita program in Mexico

At the end of last year, after 83 days of data recording, detectors of 19 sampling sites have been checked to analyze the data. In the end, 925 acoustic events were recorded!

This first part of the study already shows interesting results:

-           geographical distribution patterns of the Vaquita population are emerging. The population would be more present in the southwestern region and out of the refuge area.

-           Vaquitas seem to reduce their acoustic activity when they get close to dolphins. This behavior could bring a bias in estimations. A precise analysis about the links between the acoustic behaviors of both species will be conducted to make estimations of the number of Vaquitas more accurate.

The results of this study will improve scientific knowledge about the Vaquita distribution and will allow local actors to adapt conservation activities.

- In November, 2011 –

Very long but promising analyses!

While the acoustic sensors moored to the buoys marking out the refuge area of the vaquitas  continue to record the acoustic activity of the animals, the research team is carrying out its analysis of all of the data that was collected during the summer. Some of the data files from detectors placed in quiet areas are quickly analyzed, however most of the detectors have recorded a considerable number of sound signals. Two of these files contained more than 150 vaquita signals and took more than five days to analyze! The team is engaged in calibrating the software for analyzing the auditive data as well as identifying the signals originating from the vaquitas. The next step will be to calculate the detection rate of the species based on the different environmental parameters measured such as tides.

- In October, 2011 –

End of the season for data collection from the acoustic detectors in the Sea of Cortez

All of the acoustic equipment and mooring systems were taken up from the sea before the start of the shrimp fishing season. Unfortunately, some devices were not found at the expected locations where they had initially been placed and, despite several attempts, could not be traced. The research team has set up a reward system for fishermen who find the missing detectors. So far, two of the missing detectors have been returned by fishermen.

The team therefore has high hopes of finding the rest of the missing detectors with the help of the local fishermen. The scientific research team is now getting down to work on the analysis of the recorded data that has been collected over the last three months by the acoustic detectors.

- In September, 2011 -

The “Opel  Earth” project visits the vaquita.

15 young students and scientists from various backgrounds participated in the “Opel Earth” project, a month-long expedition in Tanzania, the Arctic and Panama.

The participants spent a week in Mexico with the Cousteau team. The scientists from the team working on the project talked to the participants about the dangers threatening the species as well as  the methods that are presently being used to study and protect them. An outing at sea in the vaquita refuge area allowed the researchers to show the participants the acoustic detector installations on the buoys that delineate the refuge. Through the media interest in their project, the “Opel Earth” participants will thus be able to inform the wider public of the threats that are presently faced by the vaquita and by a large number of other small cetacean species.

- In August, 2011 -

The vaquita acoustic detector network in place soon!

The full complement of underwater mooring systems were set up in May and June. The vaquita refuge area is thus entirely covered by the mooring systems while awaiting the setting up of the 50 acoustic detectors. It is expected that the whole of the acoustic network will be in place by September.

- In July, 2011 –

The deployment of the acoustic detector network is complete!

Following the end of the pilot study and the very positive results that were attained despite the unfavorable weather conditions, the implementation of the acoustic detector network is finally taking place. All of the mooring systems are being assembled and the acoustic C-POD detectors are being prepared for their establishment. The research team hopes to  recover the detectors at the beginning of September in order to be able to download the stored data and start analyzing the results. The detectors will be checked regularly from the time of their implementation at sea and retrieval. During the months of June and July are the International Whaling Commission meeting will examine in detail the critical case of the vaquita.

108 “acoustic encounters”!

Since the tests began, the equivalent of 540 days of data have been recorded. Of all of the acoustic data collected, 108 acoustic signals corresponded to the vaquita. In a workshop that brought together various experts in 2009, it was indicated that the equivalent of 5000 days of recorded data would be needed to achieve a sufficient degree of reliability. The Equipe Cousteau´s acoustic detector network, encompassing more than 50 detectors should attain this objective within less than 3 months of operation. The results of the pilot study are very promising and clearly confirm these predictions, the acoustic detector network will provide sufficiently accurate data on the number of vaquita for population trends to be detected.


-In June, 2011-

The Mexican government is pushing the development of new fishing nets to protect the vaquita from the risk of accidental bycatch

Whilst the analysis of data from the acoustic detector network progresses, research continues within the governmental program to develop new fishing gear that will not jeopardize the vaquita. During the last fishing season a new net prototype was used by 127 vessels, 39 of which participated in the test program organized by the Mexican National Fisheries Institute (INAPESCA).

However, as in the previous year, there were no candidates for the “Buy Out” program aimed at compensating fishermen who give up their fishing activity and take up new economic activities. The Mexican government intends to respond to the need to retrain fishermen in order to facilitate their job reconversion.

-In May, 2011-

Development of the operational acoustic detector network in the Sea of Cortez

In previous letters, the The Explorers Foundation had presented the establishment of the acoustic sensors used in the pilot study in the Sea of Cortez in Mexico. These detectors will soon be recovered and the data registered since February 2010 will be downloaded and added to the previous readings and the whole will then be analyzed. The results of these analyses will be presented to the steering committee of the Vaquita refuge area, which is responsible for carrying the conservation actions in respect of the species. The committee will then make its recommendations regarding the development and adaptation of the operational acoustic detector network, which will consist of sixty acoustic detectors crisscrossing the vaquita distribution area.

-In March, 2011-

400 days of data already recorded of the vaquitas in the Sea of Cortez!

The acoustic sensors used in the initial tests have been active since May 2010. Including the readings from the detectors put in place in November 2010, the Mexican research team already has 400 days worth of data! This first result, judged exceptional, has permitted the identification of 80 different acoustic signals close to the Rocas Consag. These results confirm previous studies on the distribution of the vaquita in the region.

- In December, 2010-

The vaquita pilot study in Mexico is under way!

The Vaquita Program pilot study began initially in that part of the Cortez Sea in Mexico designated as a «protected area» for the species. This «refuge zone» has been divided into 6 sectors and the first phase of the pilot study was conducted at 10 sites; 6 sites that correspond to the center of each sector of the refuge zone plus the sites corresponding to the buoys G, D as well as sites numbers 44 and 7 (seeMap). To ensure that this study is representative of the entire zone, the Equipe Cousteau researchers will select randomly 13 more sites to make up a total of 23 sites for the pilot study.

New conservation measures in favor of the vaquita in Mexico.

The Mexican government and several local NGOs (Alto Golfo Sustentable and Noroeste Sustentable) have launched new measures to reduce the number of fishing boats and the number of gill nets (the main threat to the vaquita) in the vaquita´s distribution area. Posters and information brochures dealing with the national vaquita conservation plan have been distributed to local communities. A program to develop alternative means for the fishermen to earn their livelihood has also been established. The integration of ecology, technology, socialsciences and economics is essential for the success of the vaquita conservation program.

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Vaquita du Mexique
Vaquita du Mexique

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