The greatest threat to finless porpoise populations is incidental mortality in fishing gear. Taken in a variety of driftnet, gillnet, trap net and trawl net fisheries. The extent of bycatch in many areas is not well documented. They are also caught in "rolling hook" gear (lines of iron hooks set across the flow of the river) in the Yangtze River, China.
The finless porpoise is distributed in the coastal waters of Asia, from the Persian Gulf, east and north to Central Japan, as far south as the northern coast of Java and the Strait of Sunda. The finless porpoise is a coastal, estuarine or riverine species and they are usually sighted near the coast.
Finless porpoises are found yearly throughout their entire range, but in some areas exhibit seasonal movements and changes in local abundance. Little is known of these changes in local abundance and distribution. Finless porpoises are currently listed in the IUCN Red List of Threatened Species as a "Data Deficient" species throughout their range, except in China where they are currently listed as "Endangered".