桃花河人工鱼巢增殖效果研究

Use of Artificial Fish Nests to Improve Fish Reproduction in Taohua River

探索产粘性卵鱼类产卵场重建的可行性,为保护渔业资源多样性和制定重要生境的修复措施提供理论基础和科学依据。2019年4-5月在重庆市长寿区桃花河开展了人工鱼巢试验,探讨人工鱼巢的增殖效果及其影响因素。研究结果显示,监测期间6个投放点人工鱼巢共采集到鱼卵11批次,出现3次产卵高峰。1、2、3、4、5、6号投放点人工鱼巢粘附鱼卵总数分别为12074、74207、360563、187472、131026和210854粒,其中,鲤占28.69%、鲫占31.96%、红鳍原鲌占39.35%。按照鱼苗的野外成活率5%估算,人工鱼巢可增殖10843尾鲤、12079尾鲫、14873尾红鳍原鲌。单因素方差分析表明,人工鱼巢的附卵均数在不同投放点间不存在显著性差异,在不同产卵批次间则存在显著性差异。Pearson相关性分析表明不同投放点人工鱼巢粘附的鱼卵数与水温、溶解氧相关。研究结果可为鱼类多样性保护和重要生境修复措施的制定提供科学依据。

Taohua River is an important tributary on the left bank of the Yangtze River. With the operation of Three Gorges Reservoir, the spawning ground area in Taohua River has dramatically decreased and fish resources have declined. Previous research shows that fish species with adhesive eggs, such as Cyprinus carpio and Carassius auratus, is an important group in Taohua River. The objective of this study was to restore the fish community, explore the feasibility of reconstructing the spawning grounds and promote sustainable development of the fishery. Artificial fish nests were set in the Taohua River in April and May of 2019, and their effect on fish reproduction, and the effects of environmental factors, were analyzed. On April 2, the artificial fish nests were placed at six sites, covering a 15 km river section, and fish spawning and eggs hatching was monitored until May 24. Adhesive eggs were collected from the artificial fish nests on 11 dates and there were three spawning peaks(April 20, 24;May 6;May 18). The average number of eggs collected from the artificial nests varied significantly among batches, but not among sites. The number of adhesive eggs collected at sites 1-6 were, respectively: 12 074, 74 207, 360 563, 187 472, 131 026 and210 854. The eggs were entirely from three species: Cyprinus carpio(28.69%), Carassius auratus(31.96%) and Cultrichthys erythropterus(39.35%). The respective recruitments to the three fish populations were 10 843, 12 079 and 14 873 individuals, assuming a 5% survival rate. Pearson correlation coefficients showed that the number of eggs adhering to the artificial nests was positively related to water temperature(P=0.009) and negatively related to dissolved oxygen(P=0.048), but not significantly related to pH or water velocity. Our results add to the scientific foundation necessary to conserve fish resource diversity and restore spawning habitat.