Environmental risk assessment of groundwater from remediated fuel spill sites on land into the marine environment at subantarctic Macquarie Island

An ecotoxicological risk assessment of groundwater from two Macquarie Island fuel spill sites was conducted to assess the level of risk posed by the sites to the adjacent marine receiving environment. Experiments were conducted on Macquarie Island during the summer season of 2017/18. The two fuel spill sites (known as: Fuel Farm and Power House, see file: Map-macquarie_building_and_structures_14676.pdf) within the vicinity of the Macquarie Island research station had undergone intensive in situ remediation by the Australian Antarctic Division over the previous decade. Despite remediation efforts, groundwater leaching from the sites continued to contain some residual fuel contamination, with sheen observed at several shoreline seeps and chemical analysis of groundwater samples confirmed some hydrocarbon contamination remained. This study aimed to assess the level of residual risk posed by groundwater from these sites as it enters the adjacent marine environment.We ran a series of toxicity tests using composited samples of salinity-adjusted groundwater discharge, as an exposure medium to test the sensitivity of 11 locally collected marine invertebrate species to the groundwater. Groundwater sampling was conducted over two periods: 23-29/11/17 and 18-20/12/17, for use in two rounds of toxicity testing (referred to as test round 1 (A and B) and test round 2). Groundwater samples were collected from 22 groundwater monitoring points; 12 surface seeps and 7 previously installed piezometers. These monitoring points were located along the coastal margin of the of the fuel spill sites, at their boundary with the adjacent marine environment (see: Locations-Fuel Farm-groundwater monitoring.pdf and Locations-Powerhouse-groundwater monitoring.pdf). The 22 groundwater samples were used to prepare seven salinity-adjusted composite test solutions (TS), each composed of equal volumes of up to nine groundwater samples. Salinity adjustment was to approximately that of ambient seawater (34 ppt), using hypersaline brine (prepared from locally collected clean seawater, which was frozen, then partially defrosted to collect concentrated brine). A total of approximately 6 L of was prepared for each of the seven TSs. See file: MI Ecotox-2017-18_TestSolutions_v03.xlsx for TS details (including: collection, preparation and physicochemical analysis results).Eleven locally collected marine invertebrate species were used in the tests. Biota were collected from two sites on Macquarie Island, both within the vicinity of the research station but away from areas of known fuel contamination: 1). Garden Bay on the East Coast (54° 29' 56.9" S, 158° 56' 28.8" E) and 2). Hasselborough Bay on the West Coast (54° 29' 45.6" S, 158° 55' 55.8" E). See: Map-macquarie_building_and_structures_14676.pdf. Dates of collection of test biota were 1/12/2017 (for test round 1A), 6/12/2017 (for test round 1B) and 20 and 22/12/17 (for test round 2). The 11 test taxa were from six broad taxonomic groups: 2 amphipods (Paramoera sp., Parawaldeckia kidderi), 2 flatworms (Obrimoposthia wandeli, Obrimoposthia ohlini), 2 copepods (Tigriopus angulatus, Harpacticus sp.), 2 gastropods (Laevilitorina caliginosa, Macquariella hamiltoni), 2 bivalves (Gaimardia trapesina, Lasaea hinemoa) and 1 isopod (Exosphaeroma gigas).Test biota were observed for 14 or 21 days and survival observed periodically. Full details of toxicity test conditions are provided in the file: MI Ecotox-2017-18_RawTestObs v02.xlsx (worksheets: TestSummary, Species and Endpoints). This file also contains, on subsequent worksheets, the raw toxicity test observations for each text taxa. These raw result data are compiled in the file: MI Ecotox-2017-18_Test-DATA.xlsx, worksheet: Survival-ALL contains survival data for all tests and taxa. Subsequent worksheets provide data for each test taxa separately and also include any sublethal observations that were made. All data associated with test solution collection, composition and chemistry are provided in the file: MI Ecotox-2017-18_TestSolutions.xlsx.The following (A. – I.) provides a description for the files provided with this record: A.    MI Ecotox-2017-18_A-Map-Groundwater monitoring sites.pngImages of study sites. A.) Overall Macquarie Island station environment, with Fuel Farm (red) and Power House (blue) indicated and showing the close proximity of the two land based sites to the adjacent high energy marine receiving environment. B.) Line map indicating relative location sites; Power House (blue) and Fuel Farm (red) sites, within the Macquarie Island station area. C.) and D.) Aerial images of the two sites, showing groundwater monitoring point locations (piezometers and seeps) used to prepare the seven test solutions (TS) as per key; Power House (TS4 and TS5) and Fuel Farm (TS1, TS2, TS3, TS6 and TS7), respectively. Monitoring point labels correspond with those provided in the file: MI Ecotox-2017-18_D-TestSolutions.xlsx / TS-Collection. B.    MI Ecotox-2017-18_B-Map-macquarie_building_and_structures_14676.pdfMap of overall Macquarie Island station area, showing locations referred to in this study relative to other station infrastructure; Fuel Farm and Power House (land based fuel contaminated sites) and Hasselborough Bay and Garden Bay (clean marine areas for collection of test biota). Produced by the Australian Antarctic Data Centre, July 2018. Map available at: https://data.aad.gov.au/aadc/mapcat/. Map Catalogue No. 14676. © Commonwealth of Australia 2018. C.    MI Ecotox-2017-18_C-RawTestObs.xlsxToxicity test condition details (in worksheets named: TestSummary, Species, Endpoints) and raw toxicity test observations for each text taxa (in subsequent worksheets).D.    MI Ecotox-2017-18_D-TestSolutions.xlsxDetails of test solutions, including collection, composition and chemistry.E.    MI Ecotox-2017-18_E-Test-DATA.xlsxCompiled raw toxicity test results in long format. Worksheet: Survival-ALL contains survival data for all tests and taxa. Subsequent worksheets provide data for each test taxa separately and includes sublethal observations if made). F.    MI Ecotox-2017-18_F-ScanLabBook.pdfScanned copy of the laboratory notebook associated with these tests. Notes were recorded by Cath King and Jessica Holan during the 17/18 Macquarie Island field season. G.    MI Ecotox-2017-18_G-ScanObservationSheets.pdfScanned copy of the handwritten raw observation sheets used to record test observations (observations scored by: Cath King and Jessica Holan). H.    MI Ecotox-2017-18_H-ChemicalAnalysis-ALS-COA.pdfCertificate of Analysis for chemistry results for samples analysed by Australian Laboratory Services (ALS) Environmental, Melbourne. Includes Total Recoverable Hydrocarbons (TRH; with and without silica gel clean up), nutrients (nitrogen) and a standard toxicity test (Microtox). Client sample ID with “Ecotox TS” prefix are those relevant to this study (other samples are associated with broader site remediation monitoring for the 17/18 season).I.    MI Ecotox-2017-18_I-ChemicalAnalysis-ALS-QAQC.pdfQuality Assurance (QA) and Quality Control (QC) report provided by ALS, in association with the Certificate of Analysis. As previous, Client sample ID with “Ecotox TS” prefix are relevant to this study. J.    MI Ecotox-2017-18_J-size measurements.zipMeasures of specimen body lengths (mm). The .zip file contains a text file named: SizeMeasurements-README.txt, providing a description of the content associated with these data.

本研究针对麦夸里岛（Macquarie Island）两处燃油泄漏场地的地下水开展生态毒理学风险评估（ecotoxicological risk assessment），以研判该类场地对邻近海洋接收环境的风险等级。实验于2017/2018年夏季在麦夸里岛开展。

两处燃油泄漏场地分别为燃油农场（Fuel Farm）与发电站（Power House），详见文件《Map-macquarie_building_and_structures_14676.pdf》；该场地位于麦夸里岛研究站周边区域，过去十年间已由澳大利亚南极局（Australian Antarctic Division）完成高强度原位修复（in situ remediation）。尽管开展了修复工作，场地淋溶出的地下水仍携带残留燃油污染：多处海岸渗流处可见油膜，且地下水样品的化学分析结果证实仍存在烃类污染。本研究旨在评估该场地地下水流入邻近海洋环境后带来的残留风险水平。

本研究采用经盐度调节的地下水排放液混合样品作为暴露介质，开展系列毒理学测试，以检验11种本地采集的海洋无脊椎动物（marine invertebrate）对该地下水的敏感性。地下水采样分为两个时段：2017年11月23日至29日，以及2017年12月18日至20日，分别用于两轮毒理学测试（分别记为测试轮次1（A、B）与测试轮次2）。

本次共从22个地下水监测点位采集样品：其中12个为地表渗流点，7个为预先安装的测压管（piezometer）。这些监测点位沿燃油泄漏场地的海岸边缘布设，紧邻邻近海洋环境的边界，详见《Locations-Fuel Farm-groundwater monitoring.pdf》与《Locations-Powerhouse-groundwater monitoring.pdf》。

将22份地下水样品混合制备为7份经盐度调节的混合测试溶液（Test Solution, TS），每份溶液由最多9份地下水样品等体积混合而成。通过高盐卤水（由本地采集的洁净海水经冷冻、部分融解后收集的浓盐水配制）将溶液盐度调节至接近环境海水水平（34 ppt）。每份混合测试溶液的制备体积约为6 L，测试溶液的详细信息（包括样品采集、制备过程与理化分析结果）详见文件《MI Ecotox-2017-18_TestSolutions_v03.xlsx》。

本次测试共使用11种本地采集的海洋无脊椎动物类群。实验生物采集自麦夸里岛研究站周边的两处未受已知燃油污染的洁净海域：1）东海岸的花园湾（Garden Bay，南纬54°29'56.9"，东经158°56'28.8"）；2）西海岸的哈塞尔伯勒湾（Hasselborough Bay，南纬54°29'45.6"，东经158°55'55.8"），详见《Map-macquarie_building_and_structures_14676.pdf》。实验生物的采集日期分别为：测试轮次1A：2017年12月1日；测试轮次1B：2017年12月6日；测试轮次2：2017年12月20日与22日。

该11个测试类群隶属于6个广义分类群：2种端足类（Paramoera sp.、Parawaldeckia kidderi）、2种扁形动物（Obrimoposthia wandeli、Obrimoposthia ohlini）、2种桡足类（Tigriopus angulatus、Harpacticus sp.）、2种腹足类（Laevilitorina caliginosa、Macquariella hamiltoni）、2种双壳类（Gaimardia trapesina、Lasaea hinemoa）以及1种等足类（Exosphaeroma gigas）。

实验生物的观测时长为14天或21天，定期记录其存活情况。毒理学测试的详细条件详见文件《MI Ecotox-2017-18_RawTestObs v02.xlsx》（工作表：TestSummary、Species and Endpoints），该文件后续工作表还包含各测试类群的原始毒理学测试观测数据。原始结果数据汇总于文件《MI Ecotox-2017-18_Test-DATA.xlsx》，其中工作表"Survival-ALL"包含所有测试与类群的存活数据，后续工作表分别提供各测试类群的单独数据，同时包含亚致死观测结果。与测试溶液采集、组成与化学性质相关的全部数据详见文件《MI Ecotox-2017-18_TestSolutions.xlsx》。

以下（A.至J.）为本次提交记录附带文件的说明：
A. MI Ecotox-2017-18_A-Map-Groundwater monitoring sites.png
研究场地影像。A）麦夸里岛研究站整体环境影像，标注了燃油农场（红色）与发电站（蓝色），展示两处陆上场地与邻近高能海洋接收环境的紧邻关系；B）麦夸里岛研究站区域内发电站（蓝色）与燃油农场（红色）相对位置的线划地图；C）与D）两处场地的航拍影像，标注了用于制备7份混合测试溶液的地下水监测点位（测压管与渗流点），对应标识如下：发电站对应TS4与TS5，燃油农场对应TS1、TS2、TS3、TS6与TS7。监测点位标签与《MI Ecotox-2017-18_D-TestSolutions.xlsx / TS-Collection》文件中的标识一致。
B. MI Ecotox-2017-18_B-Map-macquarie_building_and_structures_14676.pdf
麦夸里岛研究站整体区域地图，标注本研究涉及的场地相对于其他研究站基础设施的位置：燃油农场与发电站（陆上燃油污染场地），以及哈塞尔伯勒湾与花园湾（采集实验生物的洁净海域）。该地图由澳大利亚南极数据中心（Australian Antarctic Data Centre）于2018年7月制作，可访问https://data.aad.gov.au/aadc/mapcat/ 获取，地图目录号为14676。© 澳大利亚联邦2018年。
C. MI Ecotox-2017-18_C-RawTestObs.xlsx
毒理学测试条件详情（工作表：TestSummary、Species、Endpoints）以及各测试类群的原始毒理学测试观测数据（后续工作表）。
D. MI Ecotox-2017-18_D-TestSolutions.xlsx
混合测试溶液的详细信息，包括样品采集、组成与化学性质。
E. MI Ecotox-2017-18_E-Test-DATA.xlsx
长格式的原始毒理学测试结果汇总。工作表"Survival-ALL"包含所有测试与类群的存活数据，后续工作表分别提供各测试类群的单独数据，同时包含亚致死观测结果。
F. MI Ecotox-2017-18_F-ScanLabBook.pdf
本次测试相关实验记录本的扫描件，记录笔记由Cath King与Jessica Holan于2017/2018麦夸里岛野外季期间完成。
G. MI Ecotox-2017-18_G-ScanObservationSheets.pdf
用于记录测试观测结果的手写原始观测表扫描件，观测评分由Cath King与Jessica Holan完成。
H. MI Ecotox-2017-18_H-ChemicalAnalysis-ALS-COA.pdf
由澳大利亚实验室服务公司（Australian Laboratory Services, ALS）环境事业部（墨尔本）出具的样品分析证书，包含总可回收烃类（Total Recoverable Hydrocarbons, TRH，含硅胶净化与不含硅胶净化两种情况）、营养盐（氮）以及标准毒理学测试（Microtox）结果。以"Ecotox TS"为前缀的客户样品ID为本研究相关样品（其余样品与2017/2018季场地修复的 broader 监测相关）。
I. MI Ecotox-2017-18_I-ChemicalAnalysis-ALS-QAQC.pdf
ALS出具的与分析证书相关的质量保证（Quality Assurance, QA）与质量控制（Quality Control, QC）报告。如前所述，以"Ecotox TS"为前缀的客户样品ID为本研究相关样品。
J. MI Ecotox-2017-18_J-size measurements.zip
实验生物体长（mm）测量数据。该压缩包包含名为SizeMeasurements-README.txt的文本文件，说明该数据集的内容详情。