DataSheet_1_Industry remotely operated vehicle imagery for assessing marine communities associated with subsea oil and gas infrastructure on the continental shelf of South-East Australia.pdf

Introduction Offshore oil and gas (O & G) infrastructure provides hard substrata of structural complexity in marine environments and has been shown to have ecological value, particularly in oligotrophic environments. As infrastructure approaches end of life, understanding such values is critical to inform decommissioning decisions.
MethodsThis study uses a decade of industry remotely operated vehicle (ROV) imagery to describe fish, invertebrate, and benthic communities on gas field infrastructure. Sampling was conducted over 22 km of flowline, three wells and one manifold in the temperate waters of Bass Strait, south east Australia in depths of 155 to 263 m.
ResultsA total of 10,343 mobile animals from 69 taxa were observed. A higher diversity of fishes were observed on flowlines (28 taxa) compared to wells (19 taxa). Fish and invertebrate communities observed along flowlines were distinct from those observed on wells/manifold, however, there was also high spatial variability among the different flowlines surveyed and between the three wells and manifold. These differences appear to be driven by habitat and depth preferences of the species observed. Many sand-affiliated species were associated with buried sections of flowlines (Tasmanian giant crab Pseudocarcinus gigas, Balmain bug Ibacus peronii, slender sand burrower Creedia haswelli, red cod Pseudophycis spp., blue grenadier Macruronus novaezelandiae) whilst reef-associated and schooling species were observed on the wells/manifold (jackass morwong Nemadactylus macropterus, redbait Emmelichthys nitidus, splendid perch Callanthias australis). Species of ecological importance were also noted including the Australian fur seal (Arctocephalus pusillus doriferus), long-lived foxfish (Bodianus frenchii), and handfish (Brachionichthyidae spp).
DiscussionThis study describes the habitat value of oil and gas infrastructure in a data poor temperate region that is important for understanding how the decommissioning of these structures may affect local marine ecosystems and fisheries. Therefore, it is critical to understand the habitat value of O&G infrastructure to marine life in the Bass Strait and whether decommissioning of these structures affect local marine ecosystems and fisheries. This study shows the complexity of determining temporal change in biodiversity values associated with these O & G structures from historical industry datasets that will be key for informing future decommissioning options. We also provide some guidance on how future quantitative data can be obtained in a systematic way using industry ROV data to better inform ecological investigations and decommissioning options.

引言
近海油气（O & G）基础设施可为海洋环境提供结构复杂的硬质底质，现有研究已证实其具备生态价值，在寡营养海域尤为显著。随着这类设施逐步达到服役寿命末期，明确其生态价值可为退役决策提供关键依据。
方法
本研究依托十年间行业级遥控无人潜水器（Remotely Operated Vehicle，ROV）影像数据，对澳大利亚东南部巴斯海峡温带海域气田基础设施上的鱼类、无脊椎动物及底栖生物群落进行描述。本次采样覆盖22千米长的输气管线、3口生产井及1个管汇，作业水深介于155至263米之间。
结果
本研究共观测到69个类群的移动生物，总计10343个个体。输气管线上的鱼类物种多样性（28个类群）高于生产井区域（19个类群）。输气管线上的鱼类与无脊椎动物群落与生产井/管汇区域存在显著差异，但不同调研管线以及3口生产井与管汇之间也存在较高的空间异质性。此类差异主要由观测物种的栖息地偏好与水深偏好所驱动。诸多沙栖类群与埋设于海床的管线段相关联，包括塔斯马尼亚巨蟹（Pseudocarcinus gigas）、巴尔曼扁虾（Ibacus peronii）、细身沙钻鱼（Creedia haswelli）、红鳕属物种（Pseudophycis spp.）以及蓝尾鳕（Macruronus novaezelandiae）；而礁栖与集群性物种则见于生产井/管汇区域，包括长鳍指鲈（Nemadactylus macropterus）、红饵鱼（Emmelichthys nitidus）以及澳洲丽花鮨（Callanthias australis）。研究同时记录了多种具有重要生态价值的物种，包括澳洲海狗塔斯马尼亚亚种（Arctocephalus pusillus doriferus）、澳洲狐鲷（Bodianus frenchii）以及手鱼科（Brachionichthyidae spp.）物种。
讨论
本研究针对数据匮乏的巴斯海峡温带海域，阐述了油气基础设施的栖息地价值，这对理解这类设施退役如何影响当地海洋生态系统与渔业具有重要意义。因此，明确巴斯海峡内油气基础设施对海洋生物的栖息地价值，以及设施退役是否会影响当地海洋生态系统与渔业，具备关键的现实价值。本研究揭示了利用历史行业数据集评估这类油气设施相关生物多样性价值的时间变化的复杂性，这将为未来退役方案的制定提供核心依据。此外，本研究还为未来如何系统地利用行业级ROV数据获取定量数据以更好地支撑生态调查与退役决策提供了指导方向。