1. Vaquita (Phocoena sinus): The vaquita is critically endangered and considered the most endangered marine mammal in the world. It is a small porpoise found only in the Gulf of California, Mexico. Vaquita populations have been decimated due to bycatch in gillnets used for fishing totoaba, a large fish also found in the Gulf of California.
2. Yangtze Finless Porpoise (Neophocaena asiaeorientalis ssp. asiaeorientalis): The Yangtze finless porpoise is another critically endangered species. Found only in the Yangtze River in China, it faces numerous threats, including pollution, habitat loss due to dam construction and waterway development, and incidental catches in fishing nets.
3. Maui's Dolphin (Cephalorhynchus hectori maui): Maui's dolphin is a subspecies of Hector's dolphin and is critically endangered. It is found only in a small coastal area of New Zealand's North Island. Maui's dolphins are threatened by incidental catches in fishing nets, habitat degradation, and noise pollution from human activities.
4. Amazon River Dolphin (Inia geoffrensis): The Amazon river dolphin, also known as the boto, is vulnerable to extinction. Found in the Amazon River system, it faces threats such as habitat loss due to deforestation, pollution, and direct hunting for its meat and oil.
5. Hector's Dolphin (Cephalorhynchus hectori): Although not critically endangered, Hector's dolphin (including Maui's dolphin) is considered an endangered species. Found around the South Island of New Zealand, Hector's dolphins are vulnerable to bycatch, habitat degradation, and water pollution.
Conservation efforts are ongoing to protect these endangered dolphin species and their habitats. Governments, organizations, and individuals are working to reduce bycatch, mitigate habitat loss, combat pollution, and raise awareness about the importance of dolphin conservation.