人工鱼巢材料选择及实施效果影响因素分析

Selection of artificial fish nest material and influencing factors of implementation effects

为找出最适合的人工鱼巢材料,形成产黏性卵鱼类产卵场修复技术,该研究于2019年3—5月在西江肇庆江段利用芦竹(Arundo donax)、芒草(Miscanthus sp.)、象草(Pennisetum purpureum)、蒲葵(Livistona chinensis)、仿真水草、尼龙网布共6种材料制作人工鱼巢,分析了材料及环境因素对鱼巢实施效果的影响。结果表明,鲤(Cyprinus carpio)鱼卵对黏附介质具有较强的偏好性,芦竹制作的鱼巢有卵黏附的比例和单件鱼巢黏附鱼卵数量均显著高于其他材料制作的鱼巢(P<0.05),可知芦竹是制作鱼巢的最佳材料。有卵黏附的比例和鱼卵数量均随着入水天数的延长而下降,主成分分析表明鱼巢入水天数是影响实施效果的最主要因素,径流量和水位的上涨可促使鲤到鱼巢产卵,而天气状况对鱼巢效果影响不大。此外,还讨论了鱼巢投放时间、地点对实施效果的影响。

To determine the optimal artificial fish nest material,and to promote the restoration technology of spawning grounds for fish species with adhesive eggs,we had made fish nests with six kinds of materials(Arundo donax,Miscanthus sp.,Pennisetum purpureum,Livistona chinensis,simulation aquatic plants and nylon mesh)at Zhaoqing section in Xijiang River from March to May in 2019,and studied the effects of materials and environmental factors on the implementation of fish nests.Common carps(Cyprinus carpio)had strong preference for adhesion medium,and Arundo donax was the best material for making fish nests,since the eggs adhesion ratio and the number of eggs in each nest were significantly higher for A.donax than for the other materials(P<0.05).The eggs adhesion ratio and the number of eggs decreased with the increase of days of entering water.The principal component analysis reveals that days of entering water are the most important influencing factor on the implementation effect.The increase of discharge and rise of water level can promote common carps to gather to nests and lay eggs,but weather condition had little effect.Besides,we discussed the effects of implement time and location.