The Vaquita

 Vaquita is a marine mammal that is located in Mexico's Gulf of Carlfonia. Its among endangered species endemic to the sea of Cortez . The main reason leading to its extenction are the gillnets used in fishing totoaba, sharks, chaba and mackerels. 

Each day between November and May, gillnets are laid stretching 600m are dropped in the Cortez sea to catch totoaba which is an illegal activity. It is did that their swim bladder has a good price in the China market averaging from $20000 -$60000 per kilo.

And one more thing that's causing all these problems is that the gillnets do not only catch the totoaba, the catch the endangered species vaquita due to its ability to catch many types of fish.

There are about 9 Vaquita left according to the last statistics despites all efforts by the Mexican and UNESCO efforts to prevent the species from being extinct. According to the Andrea Crosta of Earth League International, the only way to save vaquita is to arrest all criminals involved in the illegal fishing and patrols to be done frequently.