Chat with the Experts

An interactive global forum with scientists and advocates, the 2018 digital Chat with the Experts will focus on 5 cetaceans currently facing extinction and in need of our help. Join host Greg Kaufman as he discusses the current state of the Chilean Blue Whale, Arabian Sea Humpback Whale, Vaquita, Maui Dolphin and Hawaiian False Killer Whale with experts from around the world. Submit your questions or suggested discussion points through our online forum and follow the discussion live on Tuesday, February 13.

Extinction is Forever

The blue whale is the largest animal to ever exist and was almost exterminated due to commercial whaling. The blue whale is distributed globally but is one of the rarest species of whale. Only one population in the eastern North Pacific Ocean, off California, is showing signs of recovery. Recently it was discovered that blue whales found off the southern coast of Chile may represent a unique population or a subspecies of blue whale. Based on differences in the Chilean blue whale and the other known populations, the International Whaling Commission determined that blue whales off Isla de Chiloe need to be managed as a separate population. Little is known about this population, but it appears that Chilean blue whales are the smallest population of blue whales in the Southern Hemisphere. Like other large whales, blue whales are threatened by pollution, habitat loss, overfishing, ship strikes, climate change, and becoming entangled in fishing gear.

The Maui Dolphin is a subspecies of the Hector’s dolphin, and is the world’s smallest known subspecies of dolphin. Maui dolphins are found only off the west coast of New Zealand’s North Island. This species is primarily threatened by set-netting and trawling, although disease, pollution, mining and natural predation are also factors. Estimates from 2012 showed there were only 55 individuals remaining, and many organizations have called upon the NZ government to implement greater protections. In 2014 the NZ government opened up the West Coast North Island Marine Mammal Sanctuary – the main habitat of the Maui dolphin – for oil drilling. In May 2015 the population was estimated to be 43-47 individuals, of which only 10 were reproductively mature females.

False killer whales are a large dolphin that lives in tropical and temperate waters around the world. In Hawaii there are three distinct populations of false killer whales, and the Main Hawaiian Island insular population of False Killer Whales is listed as endangered. This population has declined dramatically over the past 20 years and it is estimated that there are less than 150 individuals remaining in this population. They are impacted by interactions with fisheries, reduced food supply, and exposure to pollutants and are slow to recover from human impacts. When they were listed as endangered in 2012, the National Marine Fisheries Service  noted there is a "a probability of greather-than-90-percent likelihood of the DPS [designated population segment] declining to fewer than 20 individuals within 75 years, which would result in functional extinction beyond the point where recovery is possible".

Humpback Whales in the Arabian Sea are a discrete population of whales that does not migrate. This population lives in the Arabian Sea year-round and is the most isolated and endangered population of humpback whales, thought to contain less than 100 individuals. High productivity and upwelling create conditions suitable for feeding at latitudes where humpback whale breeding activity typically occurs. This population is one of only four that maintained its listing on the US Endangered Species Act in 2016 and is at a high risk of extinction without conservation efforts. The Arabian Sea humpback whales face unique threats, given that the whales do not migrate, but instead feed and breed in the same, relatively constrained, geographic location. Energy exploration and fishing gear entanglements are considered likely to seriously reduce the population’s size and/or growth rate, and disease, vessel collisions, and climate change are likely to moderately reduce the population’s size or growth rate.

The tiny porpoise, the Vaquita, is found only in the northern Gulf of California, Mexico. The greatest threat to this species is entanglement in gillnets. It was estimated in 2012 that there were 200 vaquitas remaining, a number which dropped to half by 2014. In 2016 the estimate was revised to be 60 vaquitas remaining and, sadly, the latest estimates, published in 2017, are only 30 individuals. The Mexican government has taken a number of steps to protect this species. They established a refuge to protect their core habitat, and banned gillnets throughout the vaquitas range. Unfortunately there is rampant illegal fishing using gillnets still occurring and it is predicted that this species could go extinct as early as 2018.