Seine+Fishing

Purse seine
==A common type of seine is a **purse seine**, named such because along the bottom are a number of rings. A rope passes through all the rings, and when pulled, draws the rings close to one another, preventing the fish from "sounding", or swimming down to escape the net. This operation is similar to a traditional style purse, which has a drawstring. == The purse seine is a preferred technique for capturing fish species which school, or aggregate, close to the surface: salmon school before they swim up rivers and streams to spawn (aggregation). Boats equipped with purse seines are called purse seiners.

Power block
The power block is a mechanized pulley used on some seiners to haul in the nets. According to the UN Food and Agriculture Organization, no single invention has contributed more to the success of purse seine net hauling than the power block. The Puretic power block line was introduced in the 1950s and was the key factor in the mechanization of purse seining. The combination of these blocks with advances in fluid hydraulics and the new large synthetic nets changed the character of purse seine fishing. The original Puretic power block was driven by an endless rope from the warping head of a winch. Nowadays, power blocks are usually driven by hydraulic pumps powered by the main or auxiliary engine. Their rpm, pull and direction can be controlled remotely. A minimum of four people are required for power block seining; the skipper, skiff operator, corkline stacker, and leadline stacker.

Drum
In Canada, specifically on the coast of British Columbia, drum seining is a method of seine fishing which was adopted in the late 1950’s and is now used exclusively in that region. The drum seine uses a horizonally mounted drum to haul and store the net instead of a power block. The net is pulled in over a roller, which spans the stern, and then passes through a spooling gear with upright rollers. The spooling gear is moved from side to side across the stern which allows the net to be guided and wound tightly on the drum. There are several advantages to the drum seine over the power block. The net can be hauled very quickly, more than twice the speed of using a power block, the net does not require overhead handling and the process is therefore safer. The most important advantage is that the drum system can be operated with fewer deckhands.