Tiny porpoises called vaquitas are vanishing and researchers don’t know if they can be saved. The vaquita, a relative of dolphins, is one of the most endangered mammals. A team of researchers investigated the reasons behind this decline and whether or not the species was likely to be saved without drastic measures. The details were just published in the journal Conservation Biology.
The vaquita (Phocoena sinus) is the rarest of the marine mammals, with an estimated wild population size of about 60 when a census was conducted in spring of 2016. They are only found in a tiny section of the Gulf of California. Vaquitas are victims of illegal fishing because they easily become tangled in gillnets intended for catching yet another endangered species: the totoaba fish. The fish are prized for their swim bladders, opening up illegal trade routes and increasing the use of gillnets. This happens so frequently that it is the main cause of the vaquita population’s decline. Pollution may be another contributing factor, as is the case for many other marine mammals. The species is critically endangered and two years ago, Mexico enacted a temporary ban on gillnet fishing and banned all fishing in their natural habitat. Unfortunately, illegal fishing has continued and populations continue to drop.
A team of researchers from Mexico’s Department of the Environment and Natural Resources used specialized acoustic detectors to detect vaquita echolocation signals. This was the only practical way to track the animals since they are both rare and small in size. Based on this information and data from previous years, the team discovered that the population was dropping by about 34% every year. The researchers also found no evidence of the gillnet ban helping the situation since illegal fishing was still rampant. The sharp population declines will put the vaquita at serious risk of extinction.
The team’s findings paint a bleak picture of the vaquita’s future. Unless gillnets are eliminated, which will take constant monitoring and enforcement, the population will die out within years. The team emphasizes the need for emergency conservation efforts to save the tiny porpoise.
Jaramillo-Legorreta et al. Passive acoustic monitoring of the decline of Mexico’s critically endangered vaquita. Conservation Biology (2016).