Relative Efficiency of Multifilament and Monofilament Nylon Gill Net Towards Lake Whitefish (Coregonus clupeaformis) in Lake Huron

Abstract

In the early 1970s Lake Huron fishermen converted their gill nets from multifilament to monofilament nylon web in the lake whitefish (Coregonus clupeaformis) fishery. Catch comparisons in the two gears showed that monofilament nets were 1.8 times more efficient (but varied seasonally), resulting in biased commercial catch statistics. The use of monofilament web has probably increased exploitation pressure on whitefish. Both gears selected whitefish of the same size despite stock differences in individual size and shape. Catches in both gears declined during the full moon phase, possibly due to increased net visibility. Key words: mono-multifilament gillnet efficiency, selectivity, lunar illuminance, Coregonus clupeaformis, Lake Huron