The Complete Handbook of Fishing Nets

Chapter 1: Understanding Fishing Nets

A fishing net is a tool designed to trap or guide fish through the interaction of three physical systems: geometry, material properties, and hydrodynamic force. Understanding how these systems work together is essential for anyone who deploys nets, because each component affects whether a net succeeds or fails in a given situation.

At its simplest, a net traps fish because the mesh openings are small enough to prevent escape but large enough to allow water to flow through freely. The water flow is critical. A net that blocks water—whether from clogging, improper deployment, or wrong mesh size—cannot work effectively. The fish sense the barrier and either refuse to enter it or struggle violently to escape, stressing them and potentially damaging the net. A properly functioning net allows water to pass through so smoothly that fish may not immediately recognize it as an obstacle.

The geometry of a net determines where and how it interacts with fish. A seine—a long rectangular net weighted at the bottom and buoyed at the top—creates a vertical barrier in the water. Its depth and length define a specific volume of water it can enclose. When you deploy a seine in a rectangular shape and pull it closed, you are compressing the target volume and directing fish toward a collection bag (called the bunt) where they concentrate. The net works because fish cannot easily escape upward or downward; they move laterally and encounter the net, then follow its contours toward the