Science NOAA and Mexican scientists collaborate to answer key questions about the vaquita. Current research focuses on abundance and abundance estimation. These efforts include: Population assessments. Bycatch estimates. Ship-based visual monitoring. Acoustic monitoring. A vaquita at the water's surface. Photo: NOAA Fisheries/Paula Olsen. Bycatch Estimates Fishermen sometimes catch and kill animals that are not their target species, such as vaquitas. This is known as bycatch. Fishermen can accidentally catch vaquitas in gillnets for fish and shrimp. Vaquitas drown once entangled in these nets. Only one study has tried to count the number of vaquitas that died in gillnets. This study took place from 1993 to 1994 at one of the three main fishing ports in the Gulf of California. The authors gathered data from observations and interviews with fishermen and estimated that 39 vaquitas were killed in gillnets that year in the port. Learn more about bycatch estimates Ship-Based Visual Monitoring Scientists conducted full abundance estimates of vaquitas in 1997, 2008, and 2015. The last full survey took place from September to December 2015. Scientists came from Mexico, the United States, the United Kingdom, and Germany to participate in the expedition. They surveyed the deeper water distribution of vaquitas from a research ship using six huge binoculars, called “big eyes.” These binoculars allow scientists to see the shy vaquitas before they react to the ship. Learn more about ship-based visual monitoring Acoustic Monitoring Acoustics monitoring estimates vaquita abundance trends by studying the echolocation clicks that vaquitas use to find their food. Mexico is a world leader in acoustic monitoring of vaquitas. Scientists use a device called a CPOD, which can pick up the high-pitch vaquita clicks for months at a time, to gather over 3,000 days of data each year. In 2015, scientists placed 134 CPODs in a grid around the vaquita habitat. Because the CPODs can be placed in shallow water, they allow scientists to monitor vaquitas in areas where ships cannot go. In the area of greatest vaquita density, scientists conducted both acoustic monitoring and visual surveys, calibrating the acoustic monitoring to the densities of vaquitas seen. The CPODs allow researchers to develop new estimates of vaquita abundance each year. For example, only about half the number of clicks were detected in 2016. Since vaquitas were estimated to have only about 60 individuals in 2015, the acoustic data mean there were only about 30 individuals in 2016. Scientists will continue this important research to collect more information about current population status. Learn more about acoustic science Read the research summary of the 2015 expedition Population Assessments Determining the number of vaquita in the wild—and how the population is changing over time—helps resource managers measure the effects of conservation actions. Data are collected using visual line transect surveys and passive acoustic monitoring.