Which of these is a method of fishing still practised in Bangladesh?

Otter fishing is a fishing technique which uses trained otters to fish in rivers. This method has been practised since the 6th century AD in various parts of the world, and is still practiced in southern Bangladesh.

Otter fishing is still practiced in Narail and Khulna districts, near the Sunderbans in southern Bangladesh. Here fishing with otters is a traditional practice in families, passed down through the generations by fishermen who breed the otters and train them to chase the fish into their nets. Otter fishing is usually done at night between 9 PM and 5 AM. The average catch by a single boat in a night ranges from 4 to 12 kilograms (8.8 to 26.5 lb) of crabs, fish and shrimp.

In 2011 there was a recorded population of 176 domesticated otters held in captivity amongst 46 groups of fishermen in these districts, of which 138 were working animals. Lack of fish, changes sought in livelihoods by the young and more economical methods of fishing have reduced the number of otter fishermen drastically.