The nets were woven from green flax, with stone weights and light wood or gourd floats, and could require hundreds of men to haul.
[3] Native Americans on the Columbia River wove seine nets from spruce root fibers or wild grass, again using stones as weights.
In ancient Roman literature, the poet Ovid makes many references to seine nets, including the use of cork floats and lead weights.
The purse seine is a preferred technique for capturing fish species which school, or aggregate, close to the surface: sardines, mackerel, anchovies, herring, and certain species of tuna (schooling); and salmon soon before they swim up rivers and streams to spawn (aggregation).
Purse seines are ranked by experts as one of the most sustainable commercial fishing methods when compared with other options.
[12] Use of purse seines is regulated by many countries; in Sri Lanka, for example, using this type of net within 7 kilometres (3.8 nmi; 4.3 mi) of the shore is illegal.
According to the UN Food and Agriculture Organization, no single invention has contributed more to the effectiveness of purse seine net hauling than the power block.
The combination of these blocks with advances in fluid hydraulics and the new large synthetic nets changed the character of purse seine fishing.
[15] A minimum of three people are required for power block seining; the skipper, skiff operator, and corkline stacker.
A Danish seine is similar to a small trawl net, but the wire warps are much longer and there are no otter boards.
A brightly coloured buoy, anchored as a "marker", serves as a fixed point when hauling the seine.
Danish seining works best on demersal fish which are either scattered on or close to the bottom of the sea, or are aggregated (schooling).
The net is deployed, with one end attached to an anchored dan (marker) buoy, by the main vessel, the seiner, or by a smaller auxiliary boat.