Reports in a new study from China are that the planet's last river-dwelling finless porpoises are dying from exposure to insecticides and mercury. Kazinform has the news.

The mammals had already been declining as their natural habitat in and around the Yangtze River deteriorated.

In the new research, scientists also found high concentrations of polychlorinated biphenyls (PCBs) and other pollutants in the organs of porpoises found in central China's Dongting Hu Lake, which is connected to the Yangtze.

"In recent decades the [Yangtze finless porpoise] population decreased sharply each year by approximately 7.3 percent because of human activities on the river, including fishing, pollution, transportation, and dam construction," said lead study author Wang Ding of China's Institute of Hydrobiology.