Primary threats:

Accidental drowning in gillnets set by fishermen meant for catching totoaba is the primary cause of anthropogenic, incidental mortality for the vaquita. Three fishing villages in the northern Gulf of California are primarily involved in the totoaba fishery and, as a result, most directly involved in threats to the vaquita. San Felipe, in Baja California, and Golfo de Santa Clara and Puerto Peñasco, in Sonora, have a total population of approximately 61,000. Up to 80% of the economy in these towns is associated with the fishing industry. A total of 1771 vessels make up the artisanal fleet that have permits to fish with nets, with the total size of the commercial fishery unknown due to the extent of the black market for totoaba[1]. Around 3,000 individuals are involved in the totoaba industry overall[2]. The total economic impact of the industry for the region is estimated to be approximately $5.4 million USD annually, or $78.5 million Pesos. Socioeconomic surveys of the northern Gulf have suggested that approximately $25 million, if invested in the region through education, equipment buyout, and job placement, could end the vaquita bycatch problem[2].

After "...saving the vaquita population.": However, even in the face of all-encompassing gillnet bans, a significant number of Mexican fishermen in El Golfo de Santa Clara continue to use the nets. As many as a third of the area's fishermen are believed to still be using gillnets despite the imposition of bans on their use [3]. Trawl nets commonly used to catch shrimp in the area may also present threats due to their impacts on the Gulf's ecosystem, either directly through bycatch or by indirectly altering the seafloor and associated species (including vaquita prey)[4].

After "reduced the flow of fresh water into the Gulf": change to:

though there is no empirical evidence that the reduced flow from the Upper Colorado River has posed an immediate short-term risk to the species[4].

Secondary impact of declining numbers:

After "...problematic if the population continues to decline.": In addition, because porpoise population growth rates are generally low, the vaquita population is unlikely to recover rapidly even after the removal of anthropogenic risk factors to their health. By some estimates, the maximum potential growth rate for the species is under 4%[4].

Recovery efforts:

after finding 31 illegal gillnets: On April 8, 2017, Sea Shepherd pulled its 200th gillnet from Mexican waters since the start of Operation Milagro III in December 2016[5].

after protective captivity was needed:

This program, called VaquitaCPR (Vaquita Conservation, Protection, and Recovery), is set to begin capturing vaquitas from the Gulf in autumn of 2017[6].

  1. ^ Action Program For the Conservation of the Species. United Mexican States Federal Government, 2008, pp. 1–76, Action Program For the Conservation of the Species.
  2. ^ a b Pitman, Robert L.; Rojas-Bracho, Lorenzo (July–August 2007). "How Now, Little Cow?". Natural History.{{cite news}}: CS1 maint: date format (link)
  3. ^ Report of the Fourth Meeting of the International Committee for the Recovery of the Vaquita (CIRVA). CIRVA, 2011, pp. 1–47, Report of the Fourth Meeting of the International Committee for the Recovery of the Vaquita (CIRVA).
  4. ^ a b c Rojas-Bracho, Lorenzo; Reeves, Randall R.; Jaramillo-Legorreta, Armando (2006). "Conservation of the vaquita Phocoena sinus". Mammal Review. 36 (3): 179–216. doi:10.1111/j.1365-2907.2006.00088.x – via JSTOR.
  5. ^ "Operation Milagro III - Home". www.seashepherd.org. Retrieved 2017-08-06.
  6. ^ "Vaquita Conservation, Protection and Recovery". National Marine Mammal Foundation. Retrieved 2017-08-06.