R. J. Slack-Smith has written and the FAO published a manual entitled Fishing with Traps and Pots. It describes the basic elements of fishing with traps and pots for small-scale fishermen. It presents the various types of traps and pots and their construcion and gives guidance on how to choose the appropriate gear, how to rig it, how to use it to improve the catch, how to select places to fish, soaking time and finally care of the catch. The document is also available (as a .pdf) for download.
From Chapter 1:
Fishing is one of the oldest ways by which people have fed themselves and their families. Except for gathering shellfish by hand and spearing fish, primitive trapping is probably the oldest form of fishing.
In early times, flowing water caused by tidal movement and changes in river and lake levels were probably used to trap fish behind rudimentary barriers, often made from sticks and stones. It is likely that early humans found that fish catches could be improved by driving fish into these barriers. They would have found that catches from these barriers decreased over time, as fish became accustomed to them, and would have had to move the traps to fresh areas where more fish could be caught. It would have been hard work to construct new traps, either by moving stones from the old trap or finding new ones. Primitive fishers probably tried making barriers from lighter, more readily available material such as tree branches, brush and vines. This led to the fishers inventing lighter, movable traps made from brush and nets made from vines which they could carry with them when they moved to new areas. They may even have tried bigger, more complicated corral-type fish traps in lakes, rivers and coastal waters.