Abstract

Toxicity bioassays measure the direct impacts of contaminants on aquatic environment. Sediment toxicity bioassay using resident species with analysis of priority chemicals accomplish the reliable risk assessment. Copepods are sensitive to environmental contaminants and widely applied for toxicity bioassays. Therefore, present study demonstrates sediment toxicity bioassay on meio-benthic harpacticoid copepod Tisbe furcata. Sediment quality parameters, metals, and total petroleum hydrocarbons (TPHs) are measured in the sediment. Pollution load index (PLI) and potential ecological risk index (PERI) are determined from metal concentration. Biological responses of copepod and sediment microbe are measured by hydrolysis of fluorescein diacetate (FDA). Sediment quality is assessed by the rate of FDA hydrolysis in comparison with sediment quality parameters. Absorbance of fluorescein in sediment extracts measured between 0.0437 and 0.0846 by copepods. Sediment toxicity response of copepods exhibited that the estuarine sediments are highly toxic with considerable ecological risk attributing higher PLI and PERI respectively. Interestingly, the toxicity bioassay exhibits moderate toxicity in the sediment samples of bar mouth and off-shore of the estuary. However, PLI and PERI reveal that these sediments are unpolluted with low ecological risk and even the impact from unknown emerging contaminants can be captured by sediment toxicity using copepod. High hydrolytic activities by sediment microbes at main stream of estuary and coastal sediments are attributed to sewage discharges. These assays are more environmentally relevant, reliable and cost-effective, and numerous tests can be conducted with basic laboratory equipments to regulate pollution.

Graphic abstract

Highlights

• Sediment toxicity bioassay on benthic copepod captured impact of pollutants.

• FDA hydrolysis by microbe can be used to assess the level of fecal contamination.

• Sediment toxicity bioassay accomplishes the ecological risk assessment.

• Bioassay described is rapid, inexpensive and aids reliable risk assessment.

中文翻译：

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桡足类 Tisbe furcata 荧光素二乙酸盐水解测定法作为一种新的快速生物测定法来评估海洋沉积物质量

摘要

毒性生物测定测量污染物对水生环境的直接影响。使用常驻物种进行沉积物毒性生物测定并分析优先化学品，完成可靠的风险评估。桡足类对环境污染物敏感，广泛应用于毒性生物测定。因此，目前的研究证明了对小型底栖棘突类桡足类Tisbe furcata 的沉积物毒性生物测定. 在沉积物中测量沉积物质量参数、金属和总石油烃 (TPH)。污染负荷指数 (PLI) 和潜在生态风险指数 (PERI) 由金属浓度确定。桡足类和沉积物微生物的生物学反应是通过双乙酸荧光素 (FDA) 的水解来测量的。沉积物质量通过 FDA 水解速率与沉积物质量参数进行评估。桡足类在 0.0437 和 0.0846 之间测量的沉积物中荧光素的吸光度。桡足类的沉积物毒性反应表明，河口沉积物是剧毒的，具有相当大的生态风险，分别归因于较高的 PLI 和 PERI。有趣的是，毒性生物测定在坝口和河口近海的沉积物样品中表现出中等毒性。然而，PLI 和 PERI 表明，这些沉积物未受污染，生态风险低，甚至可以使用桡足类通过沉积物毒性捕获未知新兴污染物的影响。河口和沿海沉积物干流中沉积物微生物的高水解活性归因于污水排放。这些检测更环保、更可靠且更具成本效益，并且可以使用基本实验室设备进行大量测试以调节污染。

图形摘要

强调

• 底栖桡足类沉积物毒性生物测定捕获污染物的影响。

• FDA 微生物水解可用于评估粪便污染水平。

• 沉积物毒性生物测定完成生态风险评估。

• 所描述的生物测定快速、廉价且有助于可靠的风险评估。