Scientists identified a distinct population of Indo-Pacific humpback dolphins in 2002, off the west coast of Taiwan. Locals knew dolphins were there, but were unaware that they were unique to Taiwan, rather than migrants from the coast of China. In 2015, this population was confirmed as a subspecies, now known as the Taiwanese white dolphin. The Eastern Taiwan Strait is a geographic barrier to these dolphins, who prefer shallower water, and therefore this population had evolved separately from those along the Chinese coast for thousands of years.
The International Union for Conservation of Nature listed the Taiwanese white dolphin as critically endangered (fewer than 75 individuals remain) soon after its discovery and retained this designation once it was confirmed as a subspecies. In 2016, AWI and other groups petitioned to have the subspecies listed as endangered under the US Endangered Species Act. Our petition was granted, and the listing was finalized by the National Marine Fisheries Service in May 2018.
The Taiwanese white dolphin urgently needs tangible actions to halt its decline and promote recovery. Taiwan’s west coast is one of the most degraded and industrialized in the world, and the dolphins are facing multiple threats. Experts in humpback dolphin biology and international and Taiwanese policy, including AWI’s Dr. Naomi Rose, participated in a workshop in Ontario, Canada—where several of the humpback dolphin experts reside—in August 2019 to prepare a recovery plan, in the hope that the Taiwanese central government would adopt it and move forward with actions that will allow this subspecies to persist into the future.
The workshop participants concluded that available knowledge is sufficient to justify moving forward with six immediate actions:
- Establish a ban on gill and trammel nets in dolphin habitat (the entire west coast of Taiwan).
- Locate any new development and related impacts away from dolphin habitat.
- Establish mandatory routes and speed limits for vessels to reduce both noise and the risk of vessel strikes in dolphin habitat.
- Reduce pollution (air, water, and soil).
- Increase natural river flows.
- Establish regulations to limit human-caused underwater noise levels in dolphin habitat.
These actions are all related to the known threats these dolphins face, which were identified in previous workshops. The most significant threat is entanglement in fishing gear. The workshop participants agreed unanimously that the gear most dangerous to the dolphins must be eliminated from dolphin habitat as soon as possible.
The benefit to dolphins of a ban on nets would be immediate, removing the subspecies’ primary source of human-caused mortality. The majority of workshop participants agreed on all of the other actions, which would reduce the negative impacts of pollution, habitat degradation, vessel strikes, and noise. However, they noted that, unlike the net ban, the benefits of these actions would take time to be realized. This recovery plan is now being shared with relevant authorities in Taiwan.