Surface nitrogen conditions associated with bottle uptake measurements during a summer 2022 Alexandrium catenella bloom in the Alaskan Arctic (NRS2022_02S)

In the rapidly changing Arctic ecosystem, the recent emergence of harmful algal blooms (HABs) threatens human and ecosystem health. There is increasing evidence that toxic dinoflagellates of the Alexandrium genus are blooming in the Pacific Arctic Ocean, in dense enough concentrations to necessitate shellfishing closures and to detect toxins in marine mammals that forge in Alaskan waters. Our understanding of the nutrient dynamics that sustain HABs in the Pacific Arctic is severely limited, particularly as these blooms tend to occur in late summer when dissolved inorganic nitrogen is drawn down and limits phytoplankton growth. Dissolved organic nitrogen could prove a critical nitrogen source for HABs in the Pacific Arctic, as it has in other regions. This dataset presents measurements taken on Leg 2 of a research cruise (NRS2022_02S) on the Research Vessel (R/V) Norseman II in Aug-Sep 2022 to characterize the nutrient usage by A. catenella. It includes the nutrients (silicate, phosophate, total dissolved nitrogen, and four dissolved nitrogen substrates), particulate organic carbon and nitrogen, and chlorophyll concentrations associated with the beginning of 13 incubation experiments in which we measured nitrogen uptake rates by the surface biological community. We also include the salinity and temperature measurements from CTD-mounted sensors for water collection from Niskin bottles for each incubation set up. Other associated datasets include: Leah McRaven & Robert Pickart. (2024). Conductivity Temperature Depth (CTD) data from the Norseman II (NRS22-1s and NRS22-2s), as part of the 2022 Origin and Fate of Harmful Algal Blooms in the Warming Chukchi Sea cruise. Arctic Data Center. doi:10.18739/A2B853K56. Evangeline Fachon, Donald M Anderson, Mrunmayee Pathare, Michael Brosnahan, Eric Muhlbach, Kali Horn, Nathaniel Spada, & Anushka Rajagopalan. (2024). Alexandrium catenella planktonic cell abundance and toxicity from the Norseman II (NRS2022_01S and NRS2022_02S), as part of the 2022 Origin and Fate of Harmful Algal Blooms in the Warming Chukchi Sea cruise. Arctic Data Center. doi:10.18739/A2804XM7S. Miguel Goni & Dean Stockwell. (2024). Conductivity-Temperature-Depth (CTD) Bottle Data from the Norseman II cruises (NRS2022_01S and NRS2022_02S) including Particulate Organic Carbon (POC) Particulate Nitrogen (PN), Chlorophyll (Chl), Phaeophytin (Phaeo), and dissolved nutrients (Nitrate, Nitrite, Phosphate, Silicate, and Ammonium) (2022). Arctic Data Center. doi:10.18739/A2M90249T.在快速演变的北极生态系统中，近期暴发的有害藻华（Harmful Algal Blooms, HABs）正威胁着人类健康与生态系统安全。越来越多的证据表明，亚历山大藻属（Alexandrium）的有毒甲藻正在北太平洋北极海域形成藻华，其种群密度足以引发贝类养殖关停，并可在阿拉斯加海域觅食的海洋哺乳动物体内检测到藻毒素。目前学界对维持北太平洋北极海域有害藻华的营养盐动力学机制的认知仍极为有限，尤其这类藻华多发生于夏末时节——此时溶解无机氮已被大量消耗，成为浮游植物生长的关键限制因子。与其他海域的研究结果一致，溶解有机氮可能是北太平洋北极海域有害藻华的关键氮源。 本数据集收录了2022年8-9月搭乘“诺森曼二世号”科考船（Research Vessel, R/V Norseman II）执行第2航次（NRS2022_02S）时获取的实测数据，旨在表征链状亚历山大藻（A. catenella）的营养盐利用特征。数据集涵盖的检测指标包括：硅酸盐、磷酸盐、总溶解氮及4种溶解氮底物等营养盐，颗粒有机碳与颗粒有机氮，以及13组培养实验初期的叶绿素浓度——这些培养实验用于测定表层生物群落的氮摄取速率。此外，本数据集还包含了为每组培养实验布设采样时，通过尼斯金采水器采集水样所配套的温盐深仪（Conductivity Temperature Depth, CTD）搭载传感器测得的盐度与温度数据。 本数据集关联的其他公开数据集包括： 1. Leah McRaven与Robert Pickart（2024）发布的《“诺森曼二世号”科考船（NRS22-1s与NRS22-2s）温盐深仪数据》，作为2022年“变暖楚科奇海有害藻华起源与归趋”科考航次的组成部分，北极数据中心，DOI: 10.18739/A2B853K56。 2. Evangeline Fachon、Donald M Anderson、Mrunmayee Pathare、Michael Brosnahan、Eric Muhlbach、Kali Horn、Nathaniel Spada及Anushka Rajagopalan（2024）发布的《“诺森曼二世号”科考船（NRS2022_01S与NRS2022_02S）链状亚历山大藻浮游细胞丰度与毒性数据》，作为2022年“变暖楚科奇海有害藻华起源与归趋”科考航次的组成部分，北极数据中心，DOI: 10.18739/A2804XM7S。 3. Miguel Goni与Dean Stockwell（2024）发布的《“诺森曼二世号”科考航次（NRS2022_01S与NRS2022_02S）温盐深仪采水器数据，包含颗粒有机碳（POC）、颗粒氮（PN）、叶绿素（Chl）、脱镁叶绿素（Phaeo）及溶解营养盐（硝酸盐、亚硝酸盐、磷酸盐、硅酸盐与铵盐）（2022）》，北极数据中心，DOI: 10.18739/A2M90249T。