Optimization of purse seines by large meshed sections and low lead weight. Theoretical considerations, sinking speed measurements and fishing trials.

摘要

Theoretical considerations on material requirements andsinking speed by use of different mesh size and lead weightin purse seines are outlined. Measurements confirmed that thesinking speed varied with mesh size and lead weight accordingto hydrodynamic theory. The sinking speed was slightlyinfluenced by mesh geometry. In fishing trials with whitelarge meshed net in the last part of a purse seine it wasnever observed that herring or mackerel escaped through thelarge meshes neither in day nor at night. The resultsindicates that the construction of herring and mackerel purseseines may be improved with an economic benefit both withregard to building costs and catch success.