Porpoises maintain mental maps, a mental image of their surroundings, which also includes the topography of the ocean floor. They use that knowledge to find their way around without having…
What is killing the vaquita?
Vaquita face a singular, deadly threat that has pushed them to the brink: entanglement in fishing nets as bycatch. Bycatch refers to the accidental capture of non-target species in fishing…
Why is by-catch in fishing nets an issue for porpoises?
Accidental by-catch in fishing nets is estimated to kill 300,000 whales, dolphins and porpoises every year. Porpoises are air-breathing mammals, so once they become stuck in a net, they only…
Why is the vaquita endangered?
The single most serious thread to the vaquita, and the cause for its rapid decline, is the use of gill-nets in the vaquita habitat.
A gill-net is a wall of netting that hangs in the water column. The mesh is designed so that fish can get their heads through, but not the rest of their bodies. As they struggle to free themselves, they get entangled with their gills. Gill-nets are very effective and used around the world, but often lead to large amounts of by-catch and pose a threat to other marine animals, such as sea turtles, seals and sea lions and cetaceans like the vaquita. If a vaquita gets entangled, it only has minutes to free itself. Most animals drown, and those that escape often do so with severe injuries.
Why is the vaquita so rare?
The vaquita, the world’s smallest and most endangered marine mammal, is a rare and elusive species found exclusively in the northern Gulf of California. With fewer than 20 individuals remaining,…
With its low numbers, can the vaquita survive despite inbreeding?
The vaquita porpoise, the world’s smallest cetacean, teeters on the brink of extinction, with fewer than 10 individuals remaining in their sole habitat in Mexico’s Gulf of California. UCLA biologists…