Serra Sónia R Q, Graça Manuel A S, Dolédec Sylvain, Feio Maria João
MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Largo Marquês de Pombal, 3004-517, Coimbra, Portugal.
Biodiversité et Plasticité dans les Hydrosystèmes, Université Lyon 1, UMR 5023 LEHNA, Bât Forel, 69622, Villeurbanne Cedex, France.
Environ Monit Assess. 2017 Jul;189(7):326. doi: 10.1007/s10661-017-6027-y. Epub 2017 Jun 9.
In freshwater ecosystems, Chironomidae are currently considered indicators of poor water quality because the family is often abundant in degraded sites. However, it incorporates taxa with a large ecological and physiological diversity and different sensitivity to impairment. Yet, the usual identification of Chironomidae at coarse taxonomic levels (family or subfamily) masks genus and species sensitivities. In this study, we investigate the potential of taxonomic and functional (traits) composition of Chironomidae to detect anthropogenic disturbance. In this context, we tested some a priori hypotheses regarding the ability of Chironomidae taxonomic and trait compositions to discriminate Mediterranean streams affected by multiple stressors from least-disturbed streams. Both taxonomic and Eltonian trait composition discriminated sites according to their disturbance level. Disturbance resulted in the predicted increase of Chironomidae with higher number of stages with hibernation/diapause and of taxa with resistance forms and unpredicted increase of the proportion of taxa with longer life cycles and few generations per year. Life history strategies (LHS), corresponding to multivoltine Chironomidae that do not invest in hemoglobin and lack strong spring synchronization, were well adapted to all our Mediterranean sites with highly changeable environmental conditions. Medium-size animals favored in disturbed sites where the Mediterranean hydrological regime is altered, but the reduced number of larger-size/carnivore Chironomids suggests a limitation to secondary production. Results indicate that Chironomidae genus and respective traits could be a useful tool in the structural and functional assessment of Mediterranean streams. The ubiquitous nature of Chironomidae should be also especially relevant in the assessment of water bodies naturally poor in other groups such as the Ephemeroptera, Plecoptera, and Trichoptera, such as the lowland rivers with sandy substrates, lakes, or reservoirs.
在淡水生态系统中，摇蚊科目前被视为水质不佳的指标，因为该科昆虫在退化的水域通常数量众多。然而，它包含了具有广泛生态和生理多样性且对损害具有不同敏感性的分类群。然而，通常在粗略分类水平（科或亚科）上对摇蚊科进行鉴定掩盖了属和种的敏感性。在本研究中，我们调查了摇蚊科的分类和功能（性状）组成在检测人为干扰方面的潜力。在此背景下，我们测试了一些先验假设，这些假设涉及摇蚊科的分类和性状组成区分受多种压力源影响的地中海溪流与受干扰最小的溪流的能力。分类组成和埃尔顿性状组成均根据干扰水平区分了不同位点。干扰导致预测的具有更多冬眠/滞育阶段的摇蚊科昆虫数量增加，具有抗性形态的分类群数量增加，以及具有较长生命周期和每年世代数较少的分类群比例出现意外增加。生活史策略（LHS），对应于不产生血红蛋白且缺乏强烈春季同步性的多化性摇蚊科昆虫，很好地适应了我们所有环境条件高度多变的地中海位点。中型动物在地中海水文状况改变的受干扰位点中占优势，但大型/肉食性摇蚊数量的减少表明次级生产受到限制。结果表明，摇蚊科的属及其各自的性状可能是地中海溪流结构和功能评估中的有用工具。摇蚊科昆虫无处不在的特性在评估其他类群（如蜉蝣目、襀翅目和毛翅目）天然匮乏的水体（如沙质底质的低地河流、湖泊或水库）时也应特别相关。
