The Relationship of Fishing Effort by Gill Nets to the Interval Between Lifts

Abstract

A description is given of the method used in analysing data from the Great Slave Lake summer fishing by which the fishing effort exerted by gill nets that are cleared every two, three, four or five days can be made comparable with the effort exerted by gill nets that are cleared daily. A comparison of catches made in 151 pairs of cases where gill nets were cleared daily and every two days under otherwise apparently identical conditions indicated that the greater the catch per net that can be made in nets that are cleared daily, the less will be the relative increase in catch per net when they are cleared every two days. It is possible to "saturate" nets after which they will catch no additional fish.