The Baiji was often caught as unintended bycatch in fishing gear, especially in gillnets. Commercial fishing activity targeting the Baiji occurred in the early 20th century, and continued even after the species gained protected status.
Habitat destruction
The construction of the Gezhouba Dam in 1981 divided the Baiji population in two. Changes in water quality following dam construction also harmed the Baiji's habitat.
Hunting
Baiji were historically hunted for food and oil, though organized commercial hunting was eventually forbidden. However, some hunting may have persisted at lower levels.
Shipping traffic
Increased ship traffic on the Yangtze, in particular due to the growth of the Chinese economy, negatively affected the Baiji. Ship collisions, habitat disruption, and propeller noise all contributed to the decline of the species.
Toxins
Chemical pollutants in the Yangtze River, such as heavy metals and organochlorines, likely harmed the health and reproductive success of the Baiji.