Drift Nets

Basking Shark © Jonas Andersson.

Drift nets consist of a string of gill-nets hung vertically in the water-column by floats on the upper line (head-rope) and weights on the lower line (ground-rope). The nets drift with the tide or current near the surface or in mid-water, with one end connected to the operating vessel. This fishing method is used to catch schooling pelagic species such as herring, mackerel and sardines, as well as salmon and tuna. The size of the mesh varies depending on the species being targeted. Drift nets entangle a fish's tail, fins and gills, wrapping it in loose netting as it struggles to escape. The setting and hauling of drift nets is generally by mechanised net haulers but they can also be hauled by hand.

Around the world, this fishing method is used to target pelagic sharks – including hammerheads (Sphyrna spp.), Oceanic Whitetips (Carcharhinus longimanus), threshers (Alopias spp.), Blue Sharks (Prionace glauca), makos (Isurus spp.) and Silky Sharks (Carcharhinus falciformis), as well as manta rays (Manta spp.). These species are also taken in tuna and billfish drift net fisheries as wanted bycatch. Bycatch of non-target and unwanted species – including marine mammals, seabirds, sharks and turtles – is the principal negative environmental impact of drift netting, as is ‘ghost fishing’ through lost or discarded nets. 


Related Links:

Fisheries and Aquaculture Organisation (FAO) website