The Gulf of California Large Marine Ecosystem is considered one of the ten marine biodiversity hotspots in the world, hosting a high diversity of marine species, including endemics and endangered, threatened or protected species. However, this ecosystem is facing critically human-induced changes that are affecting the living resources. Because of damming, the volume of freshwater discharged has decreased significantly (Arreguín-Sánchez, Francisco, et al., 2017).
This effect represents strong changes in habitat for populations such as the vaquita (Phocoena sinus), a porpoise endemic of this area, which is the most critically endangered marine small cetacean in the world. Its population has been declining notably, but almost entirely because of fishing with gillnets, which entangle and drown the animals. Although since 2015, the Mexican government imposed a ban on gillnets within the vaquita’s range, fishing continued illegally and vaquita numbers continue decreasing. Given the persistent threat, researchers have had to recur to captive breeding. This procedure consists of feeding and caring for the animals, and attempting to encourage them to breed. The final goal is to release some parents and offspring back into the wild once the danger of gillnets has been diminished (Goldfarb, 2016). Still, this method is very risky, and biologists claim it should have been done before vaquita numbers dropped to so extreme levels.
The reality is, unless the Mexican government can effectively enforce a ban on the fishing nets, there is little hope of saving the species (Pennisi, 2017).