Taiwanese humpback dolphin and calf. Photo: Claryana Araújo-Wang/CetAsia Research Group.
The Taiwanese government must act quickly to ban gill and trammel nets and stop development from further degrading the habitat of the critically endangered Taiwanese white dolphin, according to a new recovery plan drafted by an international team of marine mammal and policy experts.
Dr. Naomi Rose, marine mammal scientist for the Animal Welfare Institute (AWI) joined more than a dozen experts in cetacean biology and ecology, bioacoustics, conservation, and wildlife policy, in urging the Taiwanese government to work with scientists and other stakeholders to mitigate the threats facing the disappearing dolphin. The most serious threat is bycatch (entanglement and drowning) in fisheries, followed by habitat destruction and degradation, pollution of coastal and riverine waters, boat traffic, noise, and more recently, offshore wind farms.
Taiwanese white dolphins, also known as Taiwanese humpback dolphins, are found exclusively in the shallow waters off the western coast of Taiwan. Their skin pigment is actually white with gray spots, but when they are active, they “flush” and turn bright pink. Fewer than 75 individuals are thought to remain.
Although the dolphins are listed as an endangered species under Taiwan’s Wildlife Conservation Act (they may not be killed, captured, or disturbed), the government of Taiwan has yet to take significant action to halt their decline or promote their recovery.
More than a decade ago, in 2007, an international workshop in Changhua City concluded, “Unless tough management action is taken immediately to protect them and improve the quality of their habitat, this small group of animals unique to Taiwan will be lost forever.”
Preliminary data analysis from a long-term project that monitors the individuals in this population supports this conclusion, with fewer dolphins being observed each year.
“Taiwanese white dolphins literally have nowhere to go if their narrow strip of habitat along the west coast of Taiwan is destroyed,” Dr. Rose said in a statement. “This recovery plan is meant to assist Taiwan in ensuring this doesn’t happen.”
The recent extinction of the baiji, or Yangtze river dolphin; the impending extinction of the vaquita, a porpoise in Mexico; and the near-extinction of the Māui dolphin in New Zealand have demonstrated how quickly populations of small cetaceans with restricted distributions can disappear once their numbers have fallen below 100. As with the Taiwanese white dolphin, the primary cause of mortality for these cetaceans has always been harmful fisheries interactions, which have not been dealt with quickly enough.
The massive development of wind farms along Taiwan’s densely populated west coast represents a new threat to Taiwanese white dolphins, since it involves a substantial increase in boat traffic and construction noise, as well as functionally reducing the extent of their habitat. The proliferation of wind farms could also result in fishing efforts becoming more concentrated in the dolphins’ nearshore habitat. These negative effects on a critically endangered subspecies could be offset by eliminating the greater threat of entanglements in fishing nets.
“Taiwan could become the first jurisdiction to save a critically endangered dolphin or porpoise from being lost due to entanglement in fisheries,” said Dr. Randall R. Reeves, chair of the International Union for Conservation of Nature Species Survival Commission Cetacean Specialist Group. “It would be a tremendous accomplishment for Taiwan, its people, and the dolphins.”
A ban on gill and trammel nets is the single most urgent action needed, according to the experts. If effectively enforced, it would immediately halt the dolphins’ decline.
The group proposed a creative solution: Companies and financial institutions involved in ongoing offshore wind farm development could help finance government programs to eliminate gill and trammel nets from dolphin habitat.
“This is a ‘win-win-win’ solution, but the wind farm developers, government agencies, and fishers all have to adopt and implement it immediately to save the dolphins,” said Dr. Kurtis Pei of the National Pingtung University of Science and Technology. “As we note in the recovery plan, the developers win by resolving their conflicts with the fishing community and blunting criticism. The fishing community wins by receiving adequate compensation. Most importantly, the Taiwanese white dolphins win, as they no longer die in gill and trammel nets.”
The experts identified five other actions that may not have immediate effects, but must be implemented quickly for sustained dolphin recovery:
Locate any new development and related impacts away from the dolphins’ habitat;
Establish mandatory routes and speed limits for vessels to reduce both noise and the risk of vessel strikes;
Reduce air, water, and soil pollution;
Increase natural river flows
Establish regulations to limit human-caused underwater noise levels in dolphin habitat.