Fishing nets are in overall devided in two types, gill nets and drift nets. The type of nets the fisherman are chosing depending on what kind of fish he want to catch.
Gill nets are used to catch fish that live near the sea floor e.g. cods and flatfish like plaices, soles, turbots or similar. Those nets are placed on the bottom at fixed with anchors.
Drift nets are floating in or close to surface, and the nets are hanging vertically in the water as a curtain. Drift nets are designed to catch fish that are living near to the surface e.g. herring, trouts or makerel.
Gill nets are designed to be placed on the bottom of the sea, and this is managed by tie a number og nets togehter to a long row of nets. This row is anchored in both ends to fix them in the desired position. Gill nets has a negative buuyancy that makes it possible for the nets to sink to the bottom and catch the fish. This kind of nets can be used on almost every seafloor.
Drift nets are a type of nets that is floating in or near the surface, and you need to mark them properly thus, other wessels can pass the nets without they are causing difficulties. Drift nets are often equiped with both buoy lights and radar reflector.