The most recent assessment by the International Committee for the Recovery of the Vaquita (CIRVA) presents a sobering outlook on the vaquita’s dwindling population. In 2018, CIRVA estimated that a mere 6 to 22 individuals remained. More recent estimates suggest that this number has dropped even further, with no more than 10 vaquitas left in the wild today. To fully comprehend the severity of the situation, consider that in 1997, the vaquita population was estimated to comprise around 600 individuals—a massive decline driven by illegal fisheries.
Despite the vaquita’s dire situation, a glimmer of hope remains. In recent surveys, scientists observed several vaquitas, including mother-calf pairs, which indicates that the species continues to reproduce. Photo identification is currently being tested in addition to visual (vessel-based, with trained observers) and acoustic surveys (detection with underwater microphones) in order to obtain a better estimate of how many individuals remain.
Why is it so difficult to estimate the exact number of vaquita?
Elusive and shy by nature: Vaquitas are known for their secretive behavior, making them difficult to spot even for seasoned researchers. These elusive porpoises prefer to avoid boats and humans, further complicating efforts to locate and study them. As a result, scientists have had to develop alternative methods to estimate the vaquita population, such as using passive acoustic monitoring to detect their echolocation clicks.
Restricted habitat: The Sea of Cortez, also known as the Gulf of California, is the sole home of the vaquita. While this area is not enormous, it still spans over 62,000 square miles. The vaquitas, however, prefer a much smaller region within this vast expanse, specifically the shallow waters near the Colorado River Delta. The limited and fragmented nature of their habitat makes it challenging for researchers to conduct comprehensive surveys.
The gillnet threat: Illegal fishing practices, particularly the use of gillnets, pose the most significant threat to the vaquita population. Gillnets are designed to catch fish by their gills, but they are non-discriminatory, often trapping and killing vaquitas as bycatch. The high mortality rate caused by gillnets makes it difficult to keep an accurate count of the remaining vaquitas, as their numbers can decline rapidly between surveys.
Limited resources for monitoring: Conservation efforts for the vaquita are often hindered by a lack of funding and resources. Conducting extensive surveys and implementing effective conservation measures require substantial investments in time, technology, and manpower. With so many endangered species vying for attention and funding, the vaquita’s plight sometimes gets overshadowed.
References and Further Reading
- (2019). Report of the Eleventh meeting of the Comité Internacional para la Recuperación de la Vaquita (CIRVA). .