Data from: Marine fouling assemblages on offshore gas platforms in the southern North Sea: effects of depth and distance from shore on biodiversity

Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15–20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages.离岸平台（offshore platforms）素有“人工鱼礁”之称，但学界对其对周边海洋生物群落的影响究竟有益还是有害，目前仍存在持续争议。明确离岸平台本体及周边海域的物种组成，以及影响该物种组合的环境变量，对于深入理解离岸平台对海洋生物的影响至关重要。当前针对北海南部海域离岸平台的相关研究信息仍较为有限。本研究旨在填补这一认知空白，并探究物种组合的组成与丰度如何随水深及离岸距离梯度发生变化。研究借助遥控水下机器人（Remotely Operated Vehicles, ROV）的巡检影像，对北海南部的5座离岸天然气平台的物种组合开展了编目调查，共鉴定出30个分类单元（taxa）。物种丰富度的广义加性模型（Generalised Additive Model, GAM）结果显示，其与水深存在显著的非线性相关关系（p=0.001）：浅水区物种丰富度较低，随水深增加逐渐升高，直至15~20米，此后丰富度再次下降。通过置换多元方差分析（Permutational Multivariate Analysis of Variance, PERMANOVA）分析发现，水深（p≤0.001）、群落年龄（p≤0.001）以及离岸距离与群落年龄的交互作用（p≤0.001）对物种组合具有显著影响。未来研究应聚焦于其他额外环境变量对物种组合的影响。