In an effort to save the vaquita, (Phocoena sinus) the world's smallest member of the porpoise family, Mexico will ban the use of gill nets in the Upper Gulf of California beginning in September. Vaquitas are ensnared in gill nets fishermen use to catch totoaba, a fish species valuable in Chinese traditional medicine. Only sixty individuals are thought to survive in the wild making it the most critically endangered marine mammal in the world. {28.03.16} By the end of the year, night fishing will also be banned and fishermen will be required to land and unload at designated locations so their catch and equipment can be checked by authorities.The United States and Mexico have signed a bi-lateral agreements to enforce laws to stop illegal fishing and end the trade in totoaba swim bladders. Abandoned equipment is also posing a threat to vaquitas, so the agreements include a long term program to identify, collect and dispose of illegal and derelict fishing gear.