Photo Credit: Ryan Reisigner
By: Alice Morris
New Zealand is home to a host of remarkable creatures, among them is one of the smallest dolphins in the world; the Hector’s dolphin. They are a pint-sized mammal, measuring around 1.4 meters long, and they are the only cetacean endemic to New Zealand.
Unfortunately, these tiny dolphins face some tough challenges ahead as the two subspecies of Hector’s dolphins – the South Island Hector’s dolphin and Maui’s dolphin – face extinction.
The National Marine Fisheries Service (NMFS) released its plans in September to list the South Island Hector’s dolphins as threatened and the Maui’s dolphin as endangered under the Endangered Species Act (ESA).
The proposed ruling used scientific and commercial data to evaluate the health of the Hector’s dolphin population. Current estimates place the population of South Island Hector’s dolphins at around 12,000 to 18,5000 individuals, a 50% decrease since the 1970s.
Maui’s dolphin, which are found off the northwest coast of New Zealand’s North Island, faces a more immediate danger with an estimated population of around 80 individuals and only 55 adults.
The NMFS’s proposal urges further protection of the species to avoid extinction, citing that “the Maui’s dolphin faces serious demographic risks due to critically low abundance, a low population growth rate, a restricted range, low genetic diversity, and ongoing threats such as by-catch in commercial and recreational gill nets.”
The NMFS also proposes listing the South Island Hector’s dolphin as threatened because, though it is not currently in danger of extinction, its population has long been in decline.
Recent studies suggest that both subspecies of dolphin face human threats from boat strikes, noise, and displacement, but the NMFS report concluded that these factors did not threaten the dolphins.
Though listing Hector’s dolphin under the ESA would offer it protection from the federal government, the NMFS would not have the power to establish critical habitat for either subspecies of dolphins, because they have no jurisdiction to do so in New Zealand.
In an attempt to rebuild the Hector’s dolphin population, net bans have been set up in parts of New Zealand, but more expansive bans in addition to a recovery plan are recommended in order to restore the species population to a safe size.