AIMS@JCU, Australian Institute of Marine Science, School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia.
Mar Pollut Bull. 2012;65(4-9):363-72. doi: 10.1016/j.marpolbul.2011.09.029. Epub 2011 Oct 22.
The effects of prolonged exposure to low concentrations of herbicides on tropical periphyton (biofilm) communities are largely unknown. Tropical estuarine biofilms established in microcosms were therefore exposed to diuron (photosystem-II-inhibitor) at 2-16μg L(-1) for 4 weeks. The biofilms, consisting of diatoms, filamentous brown algae and cyanobacteria, developed a tolerance to diuron during this period as measured by Phyto-PAM fluorometry. Microscopy and pigment analysis revealed that this decrease in sensitivity was accompanied by a shift in species composition towards communities dominated by diatoms. The combination of techniques enabled the first identification of pollution-induced community tolerance (PICT) in tropical estuarine periphyton in response to chronic herbicide exposures. Community composition changed compared to controls at environmentally relevant concentrations of 1.6μg L(-1), while development of PICT was evident at 6.5μg L(-1) diuron, with no recovery (over 2 weeks) in uncontaminated water, indicating chronic pollution induced shifts in community structure.
长期暴露于低浓度除草剂对热带周丛生物（生物膜）群落的影响在很大程度上是未知的。因此，在微宇宙中建立的热带河口生物膜暴露于敌草隆（光合作用系统 II 抑制剂）浓度为 2-16μg/L，持续 4 周。生物膜由硅藻、丝状褐藻和蓝藻组成，在这段时间内通过 Phyto-PAM 荧光法测量显示出对敌草隆的耐受性。显微镜和色素分析表明，这种敏感性的降低伴随着物种组成向以硅藻为主的群落的转变。这些技术的结合使得首次在热带河口周丛生物中识别出了对慢性除草剂暴露的诱导性群落耐受（PICT）。与对照相比，在环境相关浓度 1.6μg/L 时，群落组成发生了变化，而在 6.5μg/L 敌草隆时，PICT 的发展是明显的，在未受污染的水中没有恢复（超过 2 周），表明慢性污染导致群落结构发生了变化。
