Aquatic sediments act as a source for nutrients as well as contaminants, among which there are polycyclic aromatic hydrocarbons (PAHs) such as phenanthrene (Ph), anthracene (An), pyrene (Py) and benz(a)anthracene (Ba). Phytoplankton can be an indicator of contaminants presence, thus, we decided to study it in Los Barreales reservoir (Neuquén Province, Argentina). Reservoir water and sediments were characterized, and additional samples were collected to perform assays. Bioassays were carried out by incubating sediments contaminated with increasing concentrations of PAHs and filtered lake water, with the addition of native phytoplankton: with the addition of Scenedesmus quadricauda (Turpin) Brébisson (reservoir native alga); and without sediments. The results showed that: (A) nutrient concentrations in water decreased for Ph, Py and Ba at concentrations from 500 ppm, (B) S. quadricauda abundance and chlorophyll a decreased with Ph treatments at 250 ppm (on incubation days 2 and 7), Py from 1000 ppm (on incubation day 2) and Ba from 50 ppm (on incubation days 2 and 7), and (C) that the effect of the PAHs used on algal growth was direct. Sediments contamination with Ph, Py or Ba modified nutrient concentrations in the water column and affected S. quadricauda growth.

水生沉积物是营养物和污染物的来源，其中有多环芳烃（PAH），例如菲（Ph），蒽（An），​​pyr（Py）和苯并（a）蒽（Ba）。浮游植物可以指示污染物的存在，因此，我们决定在Los Barreales水库（阿根廷Neuquén省）进行研究。对储层中的水和沉积物进行了表征，并收集了其他样品进行测定。生物测定法是通过孵育被浓度升高的多环芳烃和滤过的湖水污染的沉积物，并添加天然浮游植物来进行的：通过添加景物（Scenedesmus quadricauda）进行的（Turpin）Brébisson（水库原生藻类）；而且没有沉淀物。结果表明：（A）Ph，Py和Ba的水中养分浓度从500 ppm起降低;（B）Ph处理在250 ppm时（在孵化第2和第7天）链球菌丰度和叶绿素a下降。 ，Py从1000 ppm（在培养第2天）和Ba从50 ppm（在培养第2和7天）开始，以及（C）使用的PAHs对藻类生长的影响是直接的。沉积物被Ph，Py或Ba污染，改变了水柱中的养分浓度，并影响了S. quadricauda生长。