Bagley Justin C, Phillips Alicia K, Buchanon Sarah, O'Neil Patrick E, Huff Elizabeth S
Environmental Indicators Section, Field Operations Division, Alabama Department of Environmental Management, P.O. Box 301463, Montgomery, AL, 36130, USA.
Department of Biology and Environmental Sciences, Auburn University at Montgomery, 7061 Senators Dr., Rm. 209 O GH, Montgomery, AL, 36117, USA.
Environ Monit Assess. 2024 Dec 11;197(1):50. doi: 10.1007/s10661-024-13512-2.
The index of biotic integrity (IBI) is an effective multi-metric tool for assessing biological integrity of aquatic ecosystems and regulating water quality based on fish community surveys. Percentages of individuals with deformity, eroded fin, lesion, and tumor (DELT) anomalies are used in IBIs as a measure of fish health, while the percentage of hybrids reflects changes in reproductive isolation. When rare, these are combined into a joint '% DELT + hybrids' metric. We investigated the distribution and effects of this metric on overall fish IBI scores and biological condition ratings by analyzing data from 646 fish surveys from across Alabama. Following exploratory data analyses, we assessed the impacts of % DELT + hybrids by comparing IBI scores for sites before and after setting this metric to zero to simulate systematic error (no detection). While DELTs and other anomalies were infrequent (~ 11% of sites), the two most commonly diseased fish species were Campostoma oligolepis (Leuciscidae) and Lepomis cyanellus (Centrarchidae). Hybrids were less frequent (~ 7% of sites) than anomalies and were scored only for Lepomis sunfishes. Overall, we found no statistically significant differences in final IBI scores or biological condition ratings before and after anomaly and hybrid removal; however, removal led to increased IBI scores and biological condition ratings in 13.2% and ~ 6% of surveys, respectively. These findings demonstrate that, while IBI outcomes appear relatively robust to systematic error in % DELT + hybrids, anomaly and hybrid observations can alter IBI outcomes, with important implications for fish-based bioassessments and water quality management.
生物完整性指数（IBI）是一种有效的多指标工具，用于评估水生生态系统的生物完整性，并根据鱼类群落调查来调节水质。畸形、鳍侵蚀、损伤和肿瘤（DELT）异常个体的百分比在IBI中被用作衡量鱼类健康的指标，而杂交种的百分比则反映了生殖隔离的变化。当这些情况罕见时，它们会被合并为一个联合的“% DELT + 杂交种”指标。我们通过分析阿拉巴马州各地646次鱼类调查的数据，研究了该指标的分布及其对整体鱼类IBI得分和生物状况评级的影响。在进行探索性数据分析后，我们通过将该指标设置为零来模拟系统误差（未检测到），比较设置前后各站点的IBI得分，从而评估% DELT + 杂交种的影响。虽然DELT和其他异常情况并不常见（约占站点的11%），但两种最常患病的鱼类是寡鳞原唇鱼（鲤科）和蓝鳃太阳鱼（太阳鱼科）。杂交种比异常情况更少见（约占站点的7%），并且只对太阳鱼属进行评分。总体而言，我们发现去除异常和杂交种前后，最终的IBI得分或生物状况评级没有统计学上的显著差异；然而，去除异常和杂交种分别导致13.2%的调查中IBI得分增加，以及约6%的调查中生物状况评级提高。这些发现表明，虽然IBI结果似乎对% DELT + 杂交种中的系统误差具有相对较强的抗性，但异常和杂交种的观测结果可能会改变IBI结果，这对基于鱼类的生物评估和水质管理具有重要意义。
