Unilever Centre for Environmental Water Quality, Institute for Water Research, Rhodes University, P.O. Box 94, Makhanda Grahamstown 6140, South Africa.
Department of Animal Biology (Applied Hydrobiology and Ecotoxicology Unit), Federal University of Technology, Minna, Nigeria.
Environ Pollut. 2021 Jul 15;281:117076. doi: 10.1016/j.envpol.2021.117076. Epub 2021 Apr 9.
Urbanisation of riverine landscape is an increasing threat to the functionality of river ecosystems. In this study, we identify and classify macroinvertebrates indicator signature traits and ecological preferences.We hypothesised that urban pollution would differentially influence the distribution of macroinvertebrate traits and ecological preferences along a gradient of water quality deterioration. Hence, we identified and classified potential biological indicators traits and ecological preferences that were deemed tolerant of or sensitive to urban pollution gradient in the Niger Delta region of Nigeria. Physico-chemical variables (water temperature, depth, flow velocity, dissolved oxygen, biochemical oxygen demand, electrical conductivity (EC), nitrate, phosphate), and macroinvertebrates were collected from 2008 to 2012 seasonally during the wet and dry seasons once in a month in 11 stations in eight river systems. The results based on RLQ, fourth-corner and Kruskal-Wallis analyses indicate that traits/ecological preferences such as tegumental/cutaneous respiration, cased/tubed body armouring, a preference for silty water, bivoltinism, burrowing and a high tolerance for oxygen depletion, were statistically significantly associated with the heavily impacted stations. These traits were positively correlated with physico-chemical variables such as EC, nitrate and phosphate indicative of urban pollution. On the other hand, traits/ecological preferences such as permanent attachment, crawling, swimming, univoltinism and a moderate sensitivity to oxygen depletion were associated with the least impacted stations and were negatively correlated with physico-chemical variables indicative of urban pollution. Overall, the observed differential responses of traits and ecological preferences to urban pollution along a gradient of water quality impairment suggest that traits and ecological preferences can serve as useful biological indicators and thus supports the growing evidence of the utility of the trait-based approach.
城市化的河流景观是一个日益严重的威胁，以河流生态系统的功能。在这项研究中，我们确定和分类的大型指示生物特征和生态偏好。我们假设，城市污染会影响不同的分布特征和生态偏好的大型底栖动物沿梯度水质恶化。因此，我们确定和分类的潜在生物指标特征和生态偏好，被认为是宽容的或敏感的城市污染梯度在尼日尔三角洲地区的尼日利亚。理化变量（水温，深度，流速，溶解氧，生化需氧量，电导率（EC），硝酸盐，磷酸盐）和大型底栖动物进行了收集从 2008 年到 2012 年季节性在湿季和干季一次在一个月中的 11 个站在 8 个河流系统。结果基于 RLQ，第四角落和 Kruskal-Wallis 分析表明，特征/生态偏好，如表皮/皮肤呼吸，套管/管状身体装甲，偏好泥沙水，两化性，穴居和高耐缺氧，有统计学显著与受影响较大的车站。这些特征与理化变量如 EC，硝酸盐和磷酸盐呈正相关，指示城市污染。另一方面，特征/生态偏好，如永久附着，爬行，游泳，单化性和中度敏感缺氧与受影响最小的车站，并与理化变量呈负相关，指示城市污染。总的来说，观察到的特征和生态偏好对城市污染的差异响应沿梯度的水质恶化表明，特征和生态偏好可以作为有用的生物指标，并因此支持增长的证据表明，基于特征的方法的实用性。
