Taiwanese White Dolphin

Photo by John Wang

The Taiwanese white dolphin, also known as the Taiwanese Indo-Pacific humpback dolphin (Sousa chinensis taiwanensis)—first described after a 2002 exploratory survey—is found exclusively in the shallow waters of the western coast of Taiwan. These dolphins are eight or nine feet long with a relatively small dorsal fin, but their most distinctive characteristic is their pink coloration. Their skin pigment is actually white, with gray spots, but when they are active, they “flush” and turn bright pink. They are born dark gray with no spots, but get lighter and more spotted as they age. With a current population estimate of fewer than 751 individuals, it is overwhelmingly clear that this subspecies is at risk of extinction.

The Taiwanese white dolphin was formerly considered a subpopulation of the more broadly distributed Indo-Pacific humpback dolphin, Sousa chinensis. Through research into the degree of variation of pink and grey pigmentation between Taiwanese white dolphins and Indo-Pacific humpback dolphins, it was determined that the pigmentation is significantly different between the two populations, distinguishing the Taiwanese population as a distinct subspecies that does not cross the Eastern Taiwan Strait to interbreed with other humpback dolphins.2

Based on survey data collected between 2002 and 2006, the population was initially estimated to be 99 individuals.3 Due to this small number and the predicted decline in the population, the International Union for Conservation of Nature (IUCN) consider the Taiwanese white dolphin to be at an extremely high risk of extinction, and therefore categorize the subspecies on the Red List of Threatened Species as “Critically Endangered.” An analysis of this population found that it can suffer no more than one human-caused dolphin death every 7 to 7.6 years to remain stable. Therefore, even one human-caused mortality per year would almost certainly lead to extinction.4

In addition to being listed as Critically Endangered by the IUCN, the Taiwanese white dolphin is currently protected under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The dolphin is listed on Appendix I of the treaty, which means that commercial trade in the animal is prohibited. However, the population is not targeted for trade. While the population is at high risk of extinction due to several local and regional threats, commercial harvest is not among these. Entanglement in fishing gear, habitat destruction and degradation, pollution of coastal and riverine waters, and vessel traffic are among the most significant threats to the subspecies. Of all the human-caused threats to the survival of the Taiwanese white dolphin, fisheries bycatch is believed to be the most significant.5 Although there are various types of fishing equipment used throughout their habitat, the most likely to cause entanglements and death are gillnets and trammel nets. The subspecies is most commonly injured or killed due to the fishery for grey mullet. Fishers are unlikely to report these incidental catches or entanglements due to their fear that responsive management action will restrict their fishing activity.

Workshops were conducted in 2004, 2007, 2011, 2014, 2017, and 2019 to identify and define the dolphin’s conservation status, threats, and potential protection measures. The workshops—where scientists, policymakers, and international partners came together to discuss conservation options—promoted and fostered increased research on the population. Although data continue to be collected by researchers on the population and the threats it faces, there is little evidence of effective management steps being taken based on this information. The Taiwanese government has yet to take significant action to reduce the threats to the country’s endemic dolphin.

In March 2016, AWI, the Center for Biological Diversity, and WildEarth Guardians submitted a petition to list the Taiwanese white dolphin under the US Endangered Species Act. The National Marine Fisheries Service, after due consideration of the petition, proposed listing the subspecies as endangered in June 2017, and finalized the listing in May 2018. Protection under the law includes restrictions on trade in the animal; the ultimate goal, however, is to encourage research and increase international pressure on the government of Taiwan to take action. In addition, the United States and concerned nongovernmental organizations can provide technical expertise and resources to support Taiwan’s conservation efforts.

Since then, AWI and others have continued working to help the Taiwanese white dolphin. For example, in 2019, an international team of marine mammal science and policy experts, the Taiwanese White Dolphin Advisory Panel (TWDAP), proffered a draft recovery plan for the subspecies, which urged the Taiwanese government to work with industry, scientists, and other stakeholders to mitigate threats by banning gill and trammel nets and stopping development from further degrading the dolphins’ habitat. The draft recovery plan creatively proposed that companies and financial institutions involved in ongoing offshore wind farm development help finance government programs to eliminate gill and trammel nets from dolphin habitat. Most recently, the TWDAP has reached out to wind farm project financiers—primarily export credit agencies of Germany, Denmark, and Holland—to seek support for the recovery plan.

In July 2020, Taiwanese environmental organizations Wild at Heart and Environmental Rights Foundation joined Yunlin gillnet fishers—whose nets had been damaged by wind farm construction activities—in mobilizing to block work vessels and stop the project. High-level Taiwanese government officials interceded in mid-August to commence negotiations. During these negotiations, the environmental organizations persuaded the fishers to suggest that the wind energy industry’s buy-out of gillnets could be part of the settlement. The Yunlin fishers and an affiliate of German energy developer wpd settled in September 2020. This is significant because the two major issues for the developers have been the local marine habitat’s ecology (whose “star” is the Taiwanese white dolphin) and the fishing industry, and it is evident that the developers miscalculated at least with regard to the opposition they would face from the fishers.

In September 2020, Taiwan’s Ocean Affairs Council designated major wildlife habitat (MWH) for the Taiwanese white dolphin (similar to “critical habitat” under the US Endangered Species Act). The MWH covers about 70–80 percent of confirmed habitat, but perhaps as little as 50 percent of the MWH is confirmed suitable habitat. The designated area is identical to a “pre-announced” area floated in 2014, and contains the same flaws that international experts previously identified. While the MWH designation was an important step forward, it was perhaps more symbolic than substantive, as offshore wind activities and development have only been minimally restricted in the MWH. For example, in addition to the thousand-plus offshore wind turbines that the government plans to have installed in and adjacent to Taiwanese white dolphin MWH by the year 2035, expansion of petrochemical plants, commercial ports, gas fired power plants, and industrial parks continues unabated. This development includes major construction planned for Taichung Harbor, to accommodate expansion of a liquid natural gas (LNG) terminal. It also includes construction of a massive new LNG terminal in northwestern Taiwan, an area home to a 7,000-year-old algal reef. There, recent sightings of Taiwanese white dolphins supported scientists' recommendations that the area should be included in the subspecies’ MWH. (This area was inexplicably left out of the September 2020 MWH designation.)

AWI encourages fellow NGOs who are interested in this issue to contact Dr. Naomi Rose, AWI’s marine mammal scientist, who has been part of efforts to protect this small population of dolphins since 2007.
 

1. Dungan, S. Z., J. Y. Wang, C. C. Araújo, S.-C. Yang, and B. N. White. 2015. Social structure in a critically endangered Indo-Pacific humpback dolphin (Sousa chinensis) population. Aquatic Conservation: Marine and Freshwater Ecosystems: n/a–n/a.

2. Slooten, E., J. Wang, S. Dungan, K. Forney, S. Hung, T. Jefferson, K. Riehl, L. Rojas-Bracho, P. Ross, A. Wee, R. Winkler, S. Yang, and C. Chen. 2013. Impacts of fisheries on the Critically Endangered humpback dolphin Sousa chinensis population in the eastern Taiwan Strait. Endangered Species Research 22:99–114.

3. Wang, J. Y., S. Chu Yang, S. K. Hung, and T. A. Jefferson. 2007b. Distribution, abundance and conservation status of the eastern Taiwan Strait population of Indo-Pacific humpback dolphins, Sousa chinensis. Mammalia 71:157–165.

4. Wang, J. Y., K. N. Riehl, M. N. Klein, S. Javdan, J. M. Hoffman, S. Z. Dungan, L. E. Dares, and C. Araújo-Wang. 2015b. Biology and Conservation of the Taiwanese Humpback Dolphin, Sousa chinensis taiwanensis. Advances in Marine Biology.

5. Wang, J. Y., S. C. Yang, P. F. Fruet, F. G. Daura-Jorge, and E. R. Secchi. 2012. MarkRecapture Analysis of the Critically Endangered Eastern Taiwan Strait Population of Indo-Pacific Humpback Dolphins (Sousa Chinensis): Implications for Conservation. Bulletin of Marine Science 88:885–902.

6. Wang, J. Y., S. C. Yang, and R. R. Reeves. 2007c. Report of the second international workshop on conservation and research needs of the eastern Taiwan Strait population of indopacific humpback dolphins, Sousa chinensis. Page 65. National Museum of Marine Biology and Aquarium, Changhua City, Taiwan.

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