Hoop Net Selectivity and Catch Rates for Channel Catfish

A 2-phase study of 6 variations of hoop nets was conducted in 3 Louisiana lakes to determine if mesh size or the addition of escape rings could be used to regulate the catch of channel catfish (Ictalurus punctatus) in hoop nets. Commercial and recreational fishermen in Louisiana must abide by a 279.4-mm minimum total length restriction during a year long season. A total of 10,226 channel catfish were caught in 1,033 net days during both phases of the study. In Phase 1, 25.4-, 28.6-, and 31.8-mm (bar) mesh hoop nets were fished. For all channel catfish total lengths, the catch per unit effort (CPUE) of the hoop nets in Phase 1 increased with the decrease in mesh size of the hoop nets. There was no significant difference in the CPUE of lengths >279.4 mm among all 3 mesh sizes. CPUE of lengths <279.4 mm for the 25.4-mm mesh net (6.6) was significantly greater than the 31.8-mm mesh net (0.2). In Phase 2, 25.4-mm mesh hoop nets were altered with placement of 2 different size escape rings to provide 3 more variations of hoop nets. The total catch CPUE of the hoop nets in Phase 2 decreased with an increase in the size of the escape rings and with an increase in the number of escape rings placed in the tail of the net. The only significant difference found in the CPUE of lengths >279.4 occurred between the 25.4-mm mesh net with 4 large rings in the tail (10.3) and the 31.8-mm mesh net (4.6). The CPUE of lengths <279.4 mm in the 31.8-mm mesh net (0.3), the 25.4-mm mesh net with 8 large rings in the tail (8.2), and the 28.6-mm mesh net (8.4) were significantly less than the 25.4-mm net with small escape rings (20.3). There were no significant differences between the 28.6-mm mesh net and the 25.4-mm net modified with large rings. The total catch of the 31.8-mm mesh hoop net consisted of only 7.7% channel catfish with total lengths ≤ 279 mm. Sixty-nine percent of all channel catfish caught in the 25.4-mm mesh hoop net were ≤279 mm total length. The addition of escape rings to the 25.4-mm mesh net reduced its catch of lengths ≤279.4 mm by 22% in the most successful of the modified nets, the 25.4-mm mesh net with 8 large rings in the tail. This study shows that hoop net regulations could be used to selectively harvest length groups of channel catfish.

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