Catastrophic response of lakes to benthivorous fish introduction
Catastrophic response of lakes to benthivorous fish introduction
复制标题
DOI：
10.1034/j.1600-0706.2001.940215.x
复制
发表时间：
2001-08-01
期刊：
影响因子：
3.4
通讯作者：
Martínez-Ramos, M
中科院分区：
文献类型：
--
作者：
Zambrano, L;Scheffer, M;Martínez-Ramos, M
引入底栖性鲤鱼(鲤鱼)已被确定为全世界许多浅水湖和池塘生物多样性和水透明度丧失的主要原因之一。最近对实验鱼塘的观察表明，鲤鱼对生态系统的影响是灾难性的，因为只有当超过临界鲤鱼密度时，才会产生实质性影响。为了寻求解释，我们分析了一个简单的模型，该模型描述了底栖鱼类与其无脊椎动物底栖猎物之间的相互作用，以及鱼类摄食行为导致的沉积物再悬浮。我们的结果表明，在捕食者鱼类丰度增长到临界生物量之前，底栖猎物的数量应该只会适度减少，因为过度开发会导致底栖生物的崩溃。这种猎物密度的下降预计会导致水的浑浊度急剧增加，这是因为鱼类的猎物活动增加。对于富营养化程度较低和更深的湖泊，那里的底栖生物具有生产力，因此是底栖鱼类。承载能力较低，预计水的浑浊度受到的影响要小得多。定性模式对参数值的假设具有很强的稳健性，与实验结果和来自湖泊的数据非常吻合，表明该模型可以捕捉到底栖鱼类对湖泊生态系统造成不连续影响的机理的本质。
Introduction of the benthivorous common carp (Cyprinus carpio) has been identified as one of the main causes of loss of biodiversity and water clarity in numerous shallow lakes and ponds worldwide. Recent observations in experimental fish ponds suggest that the effect of carp on the ecosystem is catastrophic in the sense that a substantial impact occurs only when a critical carp density is exceeded. In search for an explanation, we analyzed a simple model of the interaction between benthivorous fish and their invertebrate benthic prey, and of sediment resuspension resulting from fish feeding behavior. Our results suggest that benthic prey populations should be only moderately depressed until predator fish abundance grows to a critical biomass at which benthos collapses due to overexploitation. This drop in prey density is predicted to result in a sharp increase in water turbidity due to an increase in prey search activity of the fish. For less eutrophic and deeper lakes, where benthos productivity and hence benthivorous fish. carrying capacity are lower, water turbidity is predicted to be much less affected. The qualitative patterns are quite robust against assumptions on parameter values and correspond closely to the experimental results and data from lakes suggesting that the model may capture the essence of the mechanism causing a discontinuous effect of benthivorous fish on lake ecosystems.