Fish are caught in a gillnet that hangs down stiffly when they have a head small enough to enter the mesh of the net, but a body too big to pass through that mesh; in this case, the fish get stuck – not by their gills, but by the posterior side of their gill cover (see arrow in Figure 1 below).

Why do fish die in a gill net?

When they try to back out, the netting catches them by their gills or fins, and many suffocate. Others struggle so desperately in the sharp mesh that they bleed to death. Because gill nets are set and then left unmonitored, trapped fish may suffer for days.

Does Gillnetting kill fish?

Gill netting also kills many fish caught in the net or injures fish upon removal. For this reason, gill netting must not be conducted in areas where endangered, threatened, or special-concern species may be present. Gill nets are composed of fabric mesh attached to a lead line and float line.