Taiwan environmental groups Thursday called for efforts to save highly endangered white dolphins, as they were spotted over 40 km north of their usual habitats in waters off the island's west coast.

The groups, including the Wild at Heart Legal Defense Association of Taiwan, called for efforts to draft a plan for the restoration of white dolphins and the protection of the Datan algal reef near Taoyuan city where the dolphins were recently spotted.

Chaolun Allen Chen, a researcher of white dolphins, said at a press conference held by the groups that the species' range of habitats has been shrinking rapidly due to a large number of wind power facilities along the island's west coast.

Authorities should re-evaluate the environmental impact of some projects, the environmentalists said.

White dolphins found in Taiwan are a subspecies of Chinese white dolphins. Currently, only around 60 white dolphins exist along the island's coast.