8082 - Laserfiche WebLink

Home Browse Search

Hubert and Patton: Fish Catches with Hoop Nets 5 Table2. Catch per unit effort (fish/1 00 net-nights) of the six most abundant fish species captured with two types of hoop nets in the Laramie River in 1991 and 1992. Standard error in parentheses. 1991 Species D Round Common Carp3 6.28 (1.00) 6.50 (1.58) Northern red horse 3.23 (0.99) 1.13 (0.43) White sucker2,3,4 13.56 (1.68) 10.84 (1.89) Longnose sucker3.4 1.45 (0.40) 0.97 (0.50) Channel catfish 4.26 (0.79) 5.21 (1.47) Small mouth bass1,2 3.20 (0.86) 9.21 (2.14) 1992 D Round 2.16 (0.53) 5.36 (1.83) 25.09 (2.89) 3.52 (0.69) 3.14 (0.90) 1.20 (0.33) 2.32 (0.67) 2.72 (0.70) 41.80 (5.64) 4.07 (1.04) 3.14 (0.96) 5.37 (1.29) I Significant difference between net types in 1991. 2Significant difference between net types in 1992. 3Significant difference between 1991 and 1992 with 0 nets. 4significant difference between 1991 and 1992 with round nets. the two most upstream sites, and the CPUE of channel catfish tended to increase with upstream progression. The CPUE also differed among sampling months (Fig. 3). In 1991, CPUE differed significantly among months with D nets for white suckers, and with round nets for longnose suckers. In 1992, significant differences in CPUE among months were observed with D nets for common carp and longnose suckers, and with round nets for longnose suckers. Similar patterns of CPUE among months were seen with both nets for common carp during 1991 and 1992, but were lacking for other species. The total lengths of fish captured with D nets or round nets did not differ significantly for common carp, longnose suckers, channel catfish, or smallmouth bass. However, common carp less than 400 mm were captured only with D nets (12.1 % of sample). Also, smallmouth bass less than 225 mm made up 60.7% of the D-net sample, but only 44.1 % of the round-net sample. Significantly smaller mean lengths of northern redhorse (P = 0.0203) and white suckers (P = 0.00(1) were captured with D nets than with round nets. Also, northern redhorse less than 400 mm were captured only with D nets (12.5 % of sample). Fifty percent of the white suckers captured in D nets were less than 400 mm, while only 19.1 % of the white suckers in round nets were less than 400 mm. The D nets seemed to capture smaller common carp, northern redhorse, white suckers, and smallmouth bass than round nets. DISCUSSION Our goal was to compare the catch efficiency between D nets and conven- tional round nets. We expected that the CPUE of many of the fishes in the Laramie River would be higher with D nets. Our findings did not meet our expectations. When CPUE differed between the two types of nets, the catch rates were higher with round nets.