Setting a fishing net trap

Today we found out about fishing in the Mekong River on the Vietnam / Cambodia border. Most intriguing were lines of floating houses all with net cellars in which fish are reared from birth to sale at 9 months . Average house production equals 100,000 fish at $2 per fish!
This aLternative method example shows a family group building a one entrance netting compound , very deep, and once in fish can't get out!
Well I found it interesting anyway!