Woin P
Chemical Ecology and Ecotoxicology, University of Lund, Lund, S-223 62, Sweden.
Ecotoxicol Environ Saf. 1998 Oct;41(2):137-56. doi: 10.1006/eesa.1998.1694.
Direct and secondary effects of fenvalerate on the structure of pond ecosystems were studied in six freshwater mesocosms simulating natural fish-free eutrophic ponds. Exposed mesocosms were compared with nonexposed ones and the effects of the added compound on the macroinvertebrate community were followed during three vegetation seasons (years) in two mesocosms. Exposure to fenvalerate at 1.3 and 0.54 microg liter-1 resulted in structural changes in the macroinvertebrate community. The insecticide was directly lethal to insects and other arthropods, but indirect community changes were also observed. For example, after exposure there was a remarkable (> 10-fold) increase in oligochaetes (Stylaria lacustris), probably caused by reduced predation and interspecific competition for food. When predators (insects) recolonized the system, the oligochaetes decreased in abundance and were replaced by ostracods (Herpetocypris reptans), which use similar food resources but are less susceptible to predation. The marked increase in these two taxa is probably explained by the mass death of arthropods, resulting in increased food availability. More than 2 years after treatment, the most exposed system was still different compared with nonexposed ones, suggesting that nonpersistent pesticides may produce detrimental effects resulting in long-term changes at the ecosystem level of organization.
在六个模拟无鱼天然富营养化池塘的淡水中型生态系统中，研究了氰戊菊酯对池塘生态系统结构的直接和间接影响。将暴露的中型生态系统与未暴露的进行比较，并在两个中型生态系统中跟踪添加化合物对大型无脊椎动物群落的影响，为期三个生长季节（年）。暴露于1.3和0.54微克/升的氰戊菊酯导致大型无脊椎动物群落结构发生变化。该杀虫剂对昆虫和其他节肢动物具有直接致死性，但也观察到了间接的群落变化。例如，暴露后，寡毛纲动物（湖泊柱状蚓）显著增加（超过10倍），这可能是由于捕食减少和种间食物竞争降低所致。当捕食者（昆虫）重新定殖该系统时，寡毛纲动物数量减少，并被介形纲动物（爬行赫氏介）取代，后者利用类似的食物资源，但不易被捕食。这两个类群的显著增加可能是由于节肢动物大量死亡，导致食物供应增加。处理两年多后，暴露程度最高的系统与未暴露的系统仍存在差异，这表明非持久性农药可能产生有害影响，导致生态系统组织水平的长期变化。
