ISPRA, Piazzale dei marmi, 12, 57123 Livorno, Italy.
ISPRA, Piazzale dei marmi, 12, 57123 Livorno, Italy.
Ecotoxicol Environ Saf. 2018 Mar;149:1-9. doi: 10.1016/j.ecoenv.2017.10.062. Epub 2017 Nov 13.
The copepod Acartia tonsa was used as a model species to assess marine sediment quality. Acute and chronic bioassays, such as larval development ratio (LDR) and different end-points were evaluated. As a pelagic species, A. tonsa is mainly exposed to water-soluble toxicants and bioassays are commonly performed in seawater. However, an interaction among A. tonsa eggs and the first larval stages with marine sediments might occur in shallow water environments. Here we tested two different LDR protocols by incubating A. tonsa eggs in elutriates and sediments coming from two areas located in Tuscany Region (Central Italy): Livorno harbour and Viareggio coast. The end-points analyzed were larval mortality (LM) and development inhibition (DI) expressed as the percentage of copepods that completed the metamorphosis from nauplius to copepodite. Aims of this study were: i) to verify the suitability of A. tonsa copepod for the bioassay with sediment and ii) to compare the sensitivity of A. tonsa exposed to different matrices, such as water and sediment. A preliminary acute test was also performed. Acute tests showed the highest toxicity of Livorno's samples (two out of three) compared to Viareggio samples, for which no effect was observed. On the contrary, LDR tests with sediments and elutriates revealed some toxic effects also for Viareggio's samples. Results were discussed with regards to the chemical characterization of the samples. Our results indicated that different end-points were affected in A. tonsa, depending on the matrices to which the copepods were exposed and on the test used. Bioassays with elutriates and sediments are suggested and LDR test could help decision-makers to identify a more appropriate management of dredging materials.
桡足类无节幼体被用作评估海洋沉积物质量的模式生物。急性和慢性生物测定，如幼虫发育比（LDR）和不同的终点，都进行了评估。作为浮游生物，桡足类无节幼体主要暴露于水溶性毒物中，生物测定通常在海水中进行。然而，在浅水环境中，A. tonsa 的卵和第一幼体阶段可能与海洋沉积物相互作用。在这里，我们通过在来自意大利托斯卡纳地区（意大利中部）的两个地区的洗脱物和沉积物中孵化 A. tonsa 的卵，测试了两种不同的 LDR 方案：利沃诺港和维亚雷焦海岸。分析的终点是幼虫死亡率（LM）和发育抑制（DI），表示完成从无节幼体到桡足幼体变态的桡足类无节幼体的百分比。本研究的目的是：i）验证 A. tonsa 桡足类无节幼体用于沉积物生物测定的适宜性；ii）比较暴露于不同基质（如水和沉积物）的 A. tonsa 的敏感性。还进行了初步的急性试验。急性试验表明，与维亚雷焦样本相比，利沃诺样本的毒性最高（三个样本中有两个），而维亚雷焦样本则没有观察到效果。相反，用沉积物和洗脱物进行的 LDR 试验也显示了维亚雷焦样本的一些毒性效应。结果与样本的化学特征进行了讨论。我们的结果表明，不同的终点在 A. tonsa 中受到影响，这取决于桡足类无节幼体暴露的基质和使用的测试。建议进行洗脱物和沉积物的生物测定，LDR 试验可以帮助决策者确定更合适的疏浚材料管理方法。
