Aim Mining and petroleum industries are exploring for resources in deep seafloor environments. Lease areas are often spatially aggregated and continuous over hundreds to thousands of kilometres. Sustainable development of these resources requires an understanding of the patterns of biodiversity at similar scales, yet these data are rarely available for the deep sea. Here, we compare biodiversity metrics and assemblage composition of epibenthic megafaunal samples from deep‐sea benthic habitats from the Great Australian Bight (GAB), a petroleum exploration zone off southern Australia, to similar environments off eastern Australia. Location The Great Australian Bight (34–36°S, 129–134°E) and south‐eastern (SE) and north‐eastern (NE) Australian continental margins (23–42°S, 149–155°E) in depths of 1,900–5,000 m. Methods A species–sample matrix was constructed from invertebrate and fish megafauna collected from beam trawl samples across regions at lower bathyal (1,900–3,200 m) and abyssal (>3,200 m) depths, and analysed using multivariate, rarefaction and model‐based statistics. We modelled rank abundance distributions (RAD) against environmental factors to identify drivers of abundance, richness and evenness. Results Multivariate analyses showed regional and bathymetric assemblage structure across the region. There was an almost complete turnover of sponge fauna between the GAB and SE. SE samples had the highest total faunal abundance and species richness. RAD models linked total abundance and species richness to levels of carbon flux. Evenness was associated with seasonality of net primary production. Conclusions Significant assemblage structure at regional scales is reported for the first time at lower bathyal and abyssal depths in the southern Indo‐Pacific region along latitudinal and longitudinal gradients. The GAB fauna was distinct from other studied areas. Relatively high species richness, previously reported from the GAB continental shelf, did not occur at lower bathyal or abyssal depths. Instead, the abundance, richness and evenness of the benthic fauna are linked to surface primary production, which is elevated off SE Australia.

中文翻译：

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用于保护评估的深海海底生物多样性区域尺度模式

目标 采矿和石油工业正在探索深海海底环境中的资源。租赁区域通常在空间上聚合并连续数百至数千公里。这些资源的可持续发展需要了解类似规模的生物多样性模式，但这些数据很少适用于深海。在这里，我们将来自澳大利亚南部石油勘探区大澳大利亚湾 (GAB) 的深海底栖栖息地的底栖巨型动物样本的生物多样性指标和组合组成与澳大利亚东部的类似环境进行了比较。位置 大澳大利亚湾 (34–36°S, 129–134°E) 和东南 (SE) 和东北 (NE) 澳大利亚大陆边缘 (23–42°S, 149–155°E) 的深度1,900–5,000 米。方法 物种-样本矩阵由从低半深 (1,900–3,200 m) 和深海 (>3,200 m) 深度区域的束拖网样本收集的无脊椎动物和鱼类巨型动物群构建而成，并使用多元、稀疏和基于模型的统计数据进行分析。我们针对环境因素对等级丰度分布 (RAD) 进行建模，以确定丰度、丰富度和均匀度的驱动因素。结果 多变量分析显示了该地区的区域和测深组合结构。GAB 和 SE 之间的海绵动物群几乎完全更替。SE样品具有最高的总动物群丰度和物种丰富度。RAD 模型将总丰度和物种丰富度与碳通量水平联系起来。均匀度与净初级生产的季节性有关。结论首次报道了南印度洋-太平洋地区沿纬度和经度梯度在较低的深海和深海深度的区域尺度上的显着组合结构。GAB 动物群与其他研究区域不同。先前从 GAB 大陆架报告的相对较高的物种丰富度并未发生在较低的深海或深海深度。相反，底栖动物群的丰度、丰富度和均匀度与地表初级生产有关，后者在澳大利亚东南部附近升高。没有发生在较低的深海或深海深度。相反，底栖动物群的丰度、丰富度和均匀度与地表初级生产有关，后者在澳大利亚东南部附近升高。没有发生在较低的深海或深海深度。相反，底栖动物群的丰度、丰富度和均匀度与地表初级生产有关，后者在澳大利亚东南部附近升高。