The narrow-ridged finless porpoise’s preference for coastal and riverine habitats makes it highly vulnerable to the impacts of human activities that take place in these regions (3). Although the finless porpoise is not directly targeted by fishermen, large numbers die when they become entangled in fishing nets, particularly gillnets (3) (4). The deforestation of mangrove areas, rampant harbour expansion and the development of shrimp farms is taking place throughout Asia, further degrading the narrow-ridged finless porpoise’s coastal habitat (3) (4).
Electric fishing threatens of the Yangtze finless porpoise population; despite being illegal, this destructive fishing method is widespread in the river system, not only killing some individuals outright but also depleting their prey (4).The Yangtze finless porpoise is also particularly vulnerable to habitat degradation, with the river not only being impacted by fishing and pollution, but also by the numerous dams that dot the river basin (4). The impact that these threats may have on the Yangtze finless porpoise is illustrated only too well by the tragic demise of the baiji (Lipotes vexillifer), which is believed to have gone extinct from the Yangtze River in 2006 (5).
Furthermore, high levels of toxic pollutants have been reported to affect the Japanese population of East Asian finless porpoise, and while Neophocaena species tend to avoid boats (3), mortalities caused by collisions with vessels may be a problem in busy shipping areas (4).