ABSTRACT

The common bully (Gobiomorphus cotidianus) was used as a bioindicator to assess the impacts of geothermal, bleached kraft mill effluent (BKME), sewage, and thermal discharges in the Waikato River, Northern New Zealand. A range of morphological and physiological parameters were measured to assess fitness in fish sampled upstream and downstream from these point sources. Isotopic signatures gave evidence that fish were resident at sites and showed a gradient corresponding to site-specific sources of carbon and nitrogen along the river. There were changes in the size range and age structure of the populations but, no physiological responses were detected. Limited impacts were observed on common bully health at individual discharge sites, or downstream where the river showed gradual deterioration in water quality, particularly nutrient enrichment, and increased turbidity. Despite the gradual deterioration in water quality no concomitant cumulative impacts were observed in common bully. Responses were largely local in nature, responding to point-source discharges. Population responses at the geothermal and BKME discharge sites warrant further study to investigate possible effects on fish recruitment.

摘要

常见的恶霸 ( Gobiomorphus cotidianus) 被用作评估新西兰北部怀卡托河中地热、漂白牛皮纸厂废水 (BKME)、污水和热排放的影响的生物指标。测量了一系列形态和生理参数，以评估从这些点源上游和下游采样的鱼的适应性。同位素特征提供了鱼类常驻地点的证据，并显示出与沿河特定地点碳和氮源相对应的梯度。种群的大小范围和年龄结构发生了变化，但没有检测到生理反应。在个别排放点或下游河流的水质逐渐恶化，尤其是营养物富集和浊度增加的情况下，观察到对常见恶霸健康的影响有限。尽管水质逐渐恶化，但在共同欺负者中并未观察到伴随的累积影响。响应主要是局部的，对点源排放做出响应。地热和 BKME 排放点的种群反应值得进一步研究，以调查对鱼类补充的可能影响。