Nutrient concentrations in whole mesopelagic and ground fish from two campaigns (2005, 2010) in the Kerguelen area, southern Indian Ocean

The dataset contains dry weight nutrient concentrations (20 nutrients, calcium Ca, phosphorus P, sodium Na, potassium K, magnesium Mg, strontium Sr, iron Fe, zinc Zn, copper Cu, manganese Mn, selenium Se, arsenic As, nickel Ni, cobalt Co, molybdenum Mo, chromium Cr, cadmium Cd, vanadium V, silver Ag, lead Pb) measured on 264 individuals belonging to 34 forage fish species were collected during two ship-based sampling campaigns on and around the Kerguelen Plateau. The first sampling campaign took place on the eastern slope waters of the Kerguelen Islands (49°05’–49°20’S, 71°15’–72°15’E) on the 25 m-long La Curieuse vessel in January 2005, and aimed to sample the mesopelagic fauna. Fishing operations were carried out at night, with an International Young Gadoid Pelagic Trawl (IYGPT) with 12 m x 7 m opening and 10 mm cod-end mesh deployed for 30-min at constant speed, at depth varying from 50 to 425 m (Cherel et al. 2010, Duhamel et al. 2000). Most samples caught during this campaign (n = 167) were myctophids (n = 119). The second sampling campaign (named ’Poker 2’) took place from August to October 2010 on the 77 m-long trawler FV Austral. It focused on the demersal fauna and yielded the remaining 97 fish samples. Two hundred stations from shelf and deepsea habitats were sampled during 30-min day trawling operations using a bottom trawl (35 m headline/39 m footrope, reference: G2035013 from Le Drezen: www.ledrezen.com) with a 40 mm cod-end mesh (Duhamel et al. 2017). For both campaigns, fish were sorted on board after initial identification and then kept frozen at -20°C until processing. Identification was again confirmed before sample processing relying on fish external features using published guides (Hulley 1981) and our own reference collection. In 2021-2022, each fish was thawed, rinsed with ultrapure water, measured, weighed and ground in the laboratory in a clean and contamination-free setting before being stored at -20°C. All material was carefully rinsed with ultrapure water and ethanol between samples to avoid contamination. Samples were then freeze-dried for a minimum of 72 hours and ground to a fine powder until analysis. Total concentrations of major constitutive chemical elements in biological tissues (P, Ca, K, Na, Mg) were determined by inductively coupled plasma atomic emission spectrometry (ICP-OES, Vista-Pro Varian). Aliquots of samples (∼250 mg dry mass of homogenised powder) were digested using a 6:2 (v/v) mixture with nitric acid (HNO3 69%, Trace Metal Grade®, FisherScientific) and hydrochloric acid (HCl, 34%, Trace Metal Grade®, FisherScientific). Acidic digestion of the samples was performed over-night at room temperature and then in a microwave oven (START-D, Milestone). Finally, the digestats were diluted to 50 mL with ultrapure water before analyses with ICP-OES. Total concentrations of essential trace nutrients (As, Co, Cu, Fe, Mn, Ni, Se, Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS, ICAP-Qc ThermoFisher). Aliquots of samples (∼200 mg dry mass of homogenised powder) were placed in Teflon bombs and mineralized with a mixture of ultrapure HNO3 acid (PlasmaPure Plus grade, SCP Science®) and ultrapure water using a micro-wave (ETHOS-UP, Milestone). The digests were then diluted to 50 mL with ultrapure water before analyses with ICP-MS. The quality assurance of all metal analyses relied on blank and internal standard controls, and on the accuracy and reproducibility of data relative to the certified reference materials (CRMs) used in each analytical run. The CRMs used were TORT-3 (lobster hepatopancreas, National Research Council of Canada/NRCC) and DOLT-5 (dogfish liver, NRCC). Blank values were systematically below the detection limits, and CRM values concurred with certified concentrations and recovery rates ranged between 75% and 116% depending on the nutrients and the CRMs (they are provided in the dataset).

本数据集包含20种营养元素的干重营养浓度（钙calcium Ca、磷phosphorus P、钠sodium Na、钾potassium K、镁magnesium Mg、锶strontium Sr、铁iron Fe、锌zinc Zn、铜copper Cu、锰manganese Mn、硒selenium Se、砷arsenic As、镍nickel Ni、钴cobalt Co、钼molybdenum Mo、铬chromium Cr、镉cadmium Cd、钒vanadium V、银silver Ag、铅lead Pb），数据来自克尔格伦高原及其周边海域两次船舶科考航次采集的34种饵料鱼类共264个个体的测定结果。
第一次科考航次于2005年1月在25米长的“拉居里厄斯号”（La Curieuse）科考船上开展，采样区域为克尔格伦群岛东坡海域（南纬49°05′–49°20′，东经71°15′–72°15′），旨在采集中层深海动物群。作业采用国际幼鳕中层拖网（IYGPT），网口尺寸12 m ×7 m，囊网网目尺寸10 mm，以恒定航速拖网30分钟，作业水深范围为50–425 m（Cherel等，2010；Duhamel等，2000）。本次航次捕获的167个样本中，多数为灯笼鱼科鱼类（n=119）。
第二次科考航次命名为“Poker 2”，于2010年8月至10月在77米长的拖网渔船“澳大利亚号”（FV Austral）上开展，本次航次聚焦于底栖动物类群，共获得剩余97个鱼类样本。科考团队在陆架及深海生境设置200个采样站位，采用底拖网（纲索长度35 m/底纲长度39 m，型号：Le Drezen公司G2035013，网址www.ledrezen.com）开展30分钟白昼拖网作业，囊网网目尺寸为40 mm（Duhamel等，2017）。
两次航次采集的鱼类均在甲板上完成初步分类鉴定，随后置于-20℃条件下冷冻保存直至实验室处理。样本处理前，团队依托已发表的分类图鉴（Hulley，1981）及自建的参考标本馆藏，并结合鱼类外部形态特征，再次确认鱼类物种身份。
2021–2022年，实验室在洁净无污染环境中对每条鱼进行解冻、超纯水冲洗、体长体重测定及匀浆处理，随后再次置于-20℃保存。样本间均使用超纯水及乙醇彻底冲洗实验器具，以避免交叉污染。随后将样本冷冻干燥至少72小时，研磨为细粉以待分析。
生物组织中主要常量化学元素（P、Ca、K、Na、Mg）的总浓度采用电感耦合等离子体原子发射光谱法（ICP-OES，Vista-Pro Varian）测定。称取约250 mg均质干粉样本，采用体积比6:2的硝酸（HNO3 69%，Trace Metal Grade®，FisherScientific）与盐酸（HCl 34%，Trace Metal Grade®，FisherScientific）混合溶液进行消解。样本酸消解过程为先在室温下静置过夜，随后置于微波消解仪（START-D，Milestone）中完成消解。最后将消解液用超纯水定容至50 mL，再通过ICP-OES进行浓度测定。
必需微量营养元素（As、Co、Cu、Fe、Mn、Ni、Se、Zn）的总浓度采用电感耦合等离子体质谱法（ICP-MS，ICAP-Qc ThermoFisher）测定。称取约200 mg均质干粉样本置于聚四氟乙烯消解罐中，采用超纯硝酸（PlasmaPure Plus grade，SCP Science®）与超纯水的混合体系，通过微波消解仪（ETHOS-UP，Milestone）完成矿化消解。随后将消解液用超纯水定容至50 mL，再通过ICP-MS进行浓度测定。
所有金属元素分析的质量保证措施包括空白对照、内标质控，以及依托每次分析批次中使用的标准参考物质（CRMs）验证数据的准确性与重现性。本次实验使用的标准参考物质为TORT-3（加拿大国家研究委员会/NRCC，美洲螯龙虾肝胰腺）与DOLT-5（加拿大国家研究委员会/NRCC，角鲨肝脏）。空白值均低于检测限，标准参考物质的测定值与认定浓度一致，各元素的回收率介于75%–116%之间（具体数值随元素及标准参考物质类型而异，详见数据集）。