Variations in Catchability of Fishes with Color of Gillnets

Abstract

Abstract Gillnets of nine colors were compared with white nylon to determine effects of each color on catch rates of numbers and weights of 15 species of fishes in Elephant Butte Lake. Data were analyzed with mixed-model analysis of variance. Significantly different catch rates were compared, as fractions of unity (ratios), with rates in white nets. All colors afforded positive or negative selectivity for various species. Seasonal differences in catch rates between colored and white nets were found only in clear monofilament nets. Catch rates in monofilament nets were higher than in white nets during summer when water transparency was low. Catch rates in white nets were higher from September through March when water was relatively clear and monofilament nylon appeared to break light into a spectrum. Most significant differences consisted of reduced catches in colored nets. Thus, use of colors allows selection of species along with handling smaller numbers of unwanted fish. Brown nets caught more catostomi...