What is Causing the Vaquita’s Dramatic Decline?

Vaquita populations have been in steady decline since the species was first discovered in the late 1950s. This decline is caused primarily by the use of gill-nets for fishing in the gulf. Vaquita get stuck in these nets and drown. Although gill-nets are used to catch a variety of fish species, it is the blue shrimp that has been targeted by fisherman most often since the 1950s.

Up until just a few years ago it was this high demand for the blue shrimp that was driving the Vaquita’s decline, and the population was losing roughly 4% of its individuals each year from by-catch. While this may not seem like a particularly high rate of population decline, for a species such as the Vaquita that is long-lived and has low reproductive rates, a 4% annual population decline is not sustainable.

Today, the threat to the Vaquita is even more dire. In recent years the demand for the swim bladders of a fish called the totoaba has skyrocketed. A single swim bladder from this fish can sell for $10,000 or more! Although it is illegal to harvest the totoaba, the reward for catching one is so high that fisherman largely have ignored this law. As a direct result of this situation, the Vaquita population is now declining at a rate of roughly 18% each year. Not only is this unsustainable, but if nothing dramatic is done to address this situation the species is predicted to be extinct in 3 years.

Banner photo credit: Paula Olson