The vaquita (Phocoena sinus) is the world's most endangered marine mammal and likely the most endangered animal on Earth. Fewer than 10 individuals survive in a tiny area of Mexico's Upper Gulf of California, trapped by illegal totoaba gillnet fisheries that continue despite emergency conservation measures.
Vaquitas caught in gillnets drown — an acute welfare emergency for air-breathing cetaceans. Given the tiny population, every individual death is both a welfare and conservation catastrophe simultaneously. A captive breeding attempt in 2017 failed when the only captured individual — a female — died from capture myopathy within hours of capture, illustrating the extreme stress vulnerability of this species. The welfare reality is that vaquitas may not be saveable: illegal fishing continues despite enforcement, and the population is likely already below minimum viable size. The welfare and conservation tragedy is the preventable nature of the decline — decades of warnings went unheeded.