Abstract Hydroacoustic surveys were conducted at 56 different oil and gas platforms in the U.S. Gulf of Mexico (GOM), along with a commensurate collection of physio-chemical data, in order to characterize patterns of fish distribution around platforms. Relative acoustic measurements of Mean Volume Backscatter “MVBS”, Target Strength “TS” and fish density were examined. These acoustic variables were employed to test if patterns of MVBS, TS and density around GOM platforms differed among seabed depth-based categories (Coastal: 0-30 m; Offshore: 31-60 m; Bluewater: >60 m), and how these patterns varied as a function of the distance to platforms. The acoustic measurements were also examined across the study area to determine the influence of specific environmental factors and platform features (using generalized additive mixed models (GAMMs)), and whether hypoxic waters compressed fish distribution in the water column. Significantly greater mean fish densities and MVBS occurred at Coastal sites and these variables decreased with increasing seabed depth, whilst mean TS was highest at Offshore sites. Greatest values of fish MVBS and density were found at the shortest distances (0-25 m) from platforms. GAMMs suggested that salinity and temperature had a significant effect on fish density, TS, and MVBS. The number of other platforms within 5 km also had a significant effect on MVBS. Dissolved oxygen concentration has a significant effect on fish density. Finally, we found that fish densities and MVBS were significantly higher in the depth layers immediately above hypoxic layers, demonstrating vertical compression of fishes in the water column when hypoxia occurs. Our findings provide further evidence of the influence of environmental conditions and platform features on the regional patterns of fish density, TS and MVBS around platforms, and the influence of platforms on these metrics on a local scale across the GOM. The study highlights the applicability of using hydroacoustics in conjunction with modelling to assess fish distributions around artificial habitats.

中文翻译：

---

使用水声数据了解美国墨西哥湾石油平台周围鱼类后向散射、大小和密度的模式

摘要 在美国墨西哥湾 (GOM) 的 56 个不同的石油和天然气平台上进行了水声调查，并收集了相应的理化数据，以表征平台周围鱼类的分布模式。检查了平均体积反向散射“MVBS”、目标强度“TS”和鱼密度的相对声学测量值。这些声学变量用于测试 MVBS、TS 和 GOM 平台周围密度的模式在基于海底深度的类别（沿海：0-30 m；近海：31-60 m；蓝水：>60 m）之间是否不同，以及这些模式如何模式随着到平台的距离而变化。还对整个研究区域的声学测量进行了检查，以确定特定环境因素和平台特征的影响（使用广义加性混合模型 (GAMM)），以及缺氧水域是否压缩了鱼在水体中的分布。沿海站点的平均鱼类密度和 MVBS 显着增加，这些变量随着海底深度的增加而减少，而近海站点的平均 TS 最高。在距平台最短距离 (0-25 m) 处发现了鱼类 MVBS 和密度的最大值。GAMM 表明盐度和温度对鱼类密度、TS 和 MVBS 有显着影响。5 公里内其他平台的数量也对 MVBS 有显着影响。溶解氧浓度对鱼的密度有显着影响。最后，我们发现在紧接缺氧层上方的深度层中，鱼的密度和 MVBS 显着更高，这表明发生缺氧时鱼在水体中的垂直压缩。我们的研究结果进一步证明了环境条件和平台特征对平台周围鱼类密度、TS 和 MVBS 的区域模式的影响，以及平台在整个 GOM 的局部范围内对这些指标的影响。该研究强调了使用水声结合建模来评估人工栖息地周围鱼类分布的适用性。