Strong evidence of violations of vaquita Zero Tolerance Area (ZTA)


A new report reveals evidence that many pangas have continued to use the ZTA (mostly for gillnetting). Observations of this illegal activity were made both from the sea by the Sea Shepherd Conservation Society and from land by ZTA Watch.  Pangas were present inside the ZTA on 88% of the days observed between October 2021 and May 2022 (120 of 147 days).  According to the September 2020 regulation which established the ZTA, “fishing activities of any type” are prohibited within it.  The Intergovernmental Group for Sustainability in the Upper Gulf of California established ‘trigger factors’, one of which is that when more than 65 pangas are observed to be present within the ZTA, the fishery must be closed. This trigger factor was exceeded on 5 days with no closure of the shrimp fishery or any other apparent enforcement actions.

Vaquitas not doomed to extinction by inbreeding depression

Mother and calf vaquita surface near San Felipe, Mexico. Credit: Paula Olson

New research shows that the endangered vaquita in the Gulf of California in Mexico remains genetically healthy enough for the species to recover if illegal gillnetting stops killing them.  The paper, “The critically endangered vaquita is not doomed to extinction by inbreeding depression” is based on full genome sequencing of 20 individuals collected by Mexican researchers since the 1980s and was published today in Science The scientists ran computer simulations based on the genetics of archived vaquita samples to project how the population would fare under different scenarios for their protection. They found that immediate and complete elimination of mortality from gillnets led to a high probability that the species will recover. Even low levels of continuing gillnet mortality rapidly reduced the species’ chances of survival, however.

Illegal fishing remains the sole immediate threat to vaquitas

Recent claims have been made that a reduction in illegal gillnet fishing in the northern Gulf of California is allowing for a gradual population recovery of the vaquita, Mexico’s endemic, critically endangered porpoise. Earlier recommendations by the Vaquita Recovery Team (CIRVA—Comité Internacional para la Recuperación de la Vaquita) had stressed that the vaquita could be saved from extinction only if gillnets were banned throughout its range and fishers adopted viable vaquita-safe fishing methods. In 2020, a 12 x 24 km area where the few remaining individuals were regularly found was designated a Zero Tolerance Area (ZTA), where the gillnet ban would be strictly enforced. Recent observations, however, indicate that illegal fishing is still rampant within the ZTA: during the shrimp season in October/November 2021 (Report here), 117 pangas were documented in the ZTA – the combined length of their nets could have spanned the 24-km length of the ZTA at least five times. 30 counts of pangas within the ZTA were made from the SSCS ship that indicate daily presence of illegal fishing ( see full report in English and in Spanish). On 19 January 2022 (Report here), during totoaba season, 58 pangas were counted fishing inside the ZTA, at a time when a new accord between the Mexican Navy and the Sea Shepherd Conservation Society was supposed to have greatly reduced illegal fishing within the ZTA. If vaquitas are to be saved from extinction, at a minimum, the ban on gillnet fishing in the ZTA must be enforced, and current evidence indicates that this is not happening.


Documenting illegal fishing has been difficult but photographs taken during the 2019 and 2021 vaquita surveys within the ZTA (see below) show gillnets clearly visible on pangas in the launch areas and in use within the ZTA. A video of pangas  launching from downtown San Felipe, with gillnets clearly visible as the only gear in use  is provided here.