Stefano Bonaglia, Henry L. S. Cheung, Tobia Politi, Irma Vybernaite-Lubiene, Tristan McKenzie, Isaac R. Santos, Mindaugas Zilius
Coastal lagoons are important nutrient filters and carbon sinks but may release large amounts of methane (CH4) to the atmosphere. Here, we hypothesize that eutrophication and population density will turn coastal lagoons into stronger methane emitters. We report benthic fluxes from 187 sediment cores incubated from three of the largest European lagoons suffering persistent eutrophication. Methane fluxes were mainly driven by sediment porosity, organic matter, and dissolved inorganic carbon (DIC) fluxes. Methane was always supersaturated (250–49,000%) in lagoon waters leading to large, variable emissions of 0.04–26 mg CH4 m−2 d−1. Combining our new dataset with earlier estimates revealed a global coastal lagoon emission of 7.9 (1.4–34.7) Tg CH4 yr−1 with median values of 5.4 mg CH4 m−2 d−1. Lagoons with very highly populated catchments released much more methane (223 mg CH4 m−2 d−1). Overall, projected increases in eutrophication, organic loading and population densities will enhance methane fluxes from lagoons worldwide.
{"title":"Eutrophication and urbanization enhance methane emissions from coastal lagoons","authors":"Stefano Bonaglia, Henry L. S. Cheung, Tobia Politi, Irma Vybernaite-Lubiene, Tristan McKenzie, Isaac R. Santos, Mindaugas Zilius","doi":"10.1002/lol2.10430","DOIUrl":"10.1002/lol2.10430","url":null,"abstract":"<p>Coastal lagoons are important nutrient filters and carbon sinks but may release large amounts of methane (CH<sub>4</sub>) to the atmosphere. Here, we hypothesize that eutrophication and population density will turn coastal lagoons into stronger methane emitters. We report benthic fluxes from 187 sediment cores incubated from three of the largest European lagoons suffering persistent eutrophication. Methane fluxes were mainly driven by sediment porosity, organic matter, and dissolved inorganic carbon (DIC) fluxes. Methane was always supersaturated (250–49,000%) in lagoon waters leading to large, variable emissions of 0.04–26 mg CH<sub>4</sub> m<sup>−2</sup> d<sup>−1</sup>. Combining our new dataset with earlier estimates revealed a global coastal lagoon emission of 7.9 (1.4–34.7) Tg CH<sub>4</sub> yr<sup>−1</sup> with median values of 5.4 mg CH<sub>4</sub> m<sup>−2</sup> d<sup>−1</sup>. Lagoons with very highly populated catchments released much more methane (223 mg CH<sub>4</sub> m<sup>−2</sup> d<sup>−1</sup>). Overall, projected increases in eutrophication, organic loading and population densities will enhance methane fluxes from lagoons worldwide.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 1","pages":"140-150"},"PeriodicalIF":5.1,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui Zhang, Stéphane Blain, Corentin Baudet, Hélène Planquette, Frédéric Vivier, Philippe Catala, Olivier Crispi, Audrey Guéneuguès, Barbara Marie, Pavla Debeljak, Ingrid Obernosterer
Marine microbes are strongly interrelated to trace metals in the ocean. How the availability of trace metals selects for prokaryotic taxa and the potential feedback of microbial processes on the trace metal distribution in the ocean remain poorly understood. We investigate here the potential reciprocal links between diverse prokaryotic taxa and iron (Fe), manganese (Mn), copper (Cu), and nickel (Ni) as well as apparent oxygen utilization (AOU) across 12 well-defined water masses in the Southern Indian Ocean (SWINGS—South West Indian Ocean GEOTRACES GS02 Section cruise). Applying partial least square regression (PLSR) analysis, we show that the water masses are associated with particular latent vectors that are a combination of the spatial distribution of prokaryotic taxa, trace elements, and AOU. This approach provides novel insights on the potential interactions between prokaryotic taxa and trace metals in relation to organic matter remineralization in distinct water masses of the ocean.
{"title":"Tagging of water masses with covariance of trace metals and prokaryotic taxa in the Southern Ocean","authors":"Rui Zhang, Stéphane Blain, Corentin Baudet, Hélène Planquette, Frédéric Vivier, Philippe Catala, Olivier Crispi, Audrey Guéneuguès, Barbara Marie, Pavla Debeljak, Ingrid Obernosterer","doi":"10.1002/lol2.10429","DOIUrl":"10.1002/lol2.10429","url":null,"abstract":"<p>Marine microbes are strongly interrelated to trace metals in the ocean. How the availability of trace metals selects for prokaryotic taxa and the potential feedback of microbial processes on the trace metal distribution in the ocean remain poorly understood. We investigate here the potential reciprocal links between diverse prokaryotic taxa and iron (Fe), manganese (Mn), copper (Cu), and nickel (Ni) as well as apparent oxygen utilization (AOU) across 12 well-defined water masses in the Southern Indian Ocean (<i>SWINGS—South West Indian Ocean GEOTRACES GS02 Section</i> cruise). Applying partial least square regression (PLSR) analysis, we show that the water masses are associated with particular latent vectors that are a combination of the spatial distribution of prokaryotic taxa, trace elements, and AOU. This approach provides novel insights on the potential interactions between prokaryotic taxa and trace metals in relation to organic matter remineralization in distinct water masses of the ocean.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 6","pages":"776-784"},"PeriodicalIF":5.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10429","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142042544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas S. Marzolf, Michael J. Vlah, Heili E. Lowman, Weston M. Slaughter, Emily S. Bernhardt
Modeling and sensor innovations in the last decade have enabled routine and continuous estimation of daily gross primary productivity (GPP) for rivers. Here, we generate and evaluate within and across year variability for 59 US rivers for which we have compiled a 14-yr time series of daily GPP estimates. River productivity varied widely across (median annual GPP 462 g C m−2 yr−1, range 19–3445 g C m−2 yr−1) and within rivers (CVGPP-Inter 5.7–37.3%). Within this dataset, we found that five rivers have become consistently more productive over time, while 11 rivers have become consistently less productive. Furthermore, trends in ecosystem phenology were identified, where cumulative annual GPP was reached earlier (n = 3) and later (n = 13) in the year across the 25th, 50th, 75th, and 95th percentiles. Understanding the drivers of productivity trends in rivers will elucidate patterns in river food webs and the functional role of river biogeochemistry.
过去十年中,建模和传感器的创新使我们能够对河流的每日总初级生产力(GPP)进行常规、连续的估算。在此,我们生成并评估了美国 59 条河流的年内和跨年变异性,并对其进行了 14 年的每日总初级生产力估算时间序列。不同河流之间(年 GPP 中位数为 462 g C m-2 yr-1,范围为 19-3445 g C m-2 yr-1)和河流内部(CVGPP-Inter 5.7-37.3%)的河流生产力差异很大。在该数据集中,我们发现随着时间的推移,5 条河流的生产力持续提高,而 11 条河流的生产力持续降低。此外,我们还发现了生态系统物候学的趋势,在第 25、50、75 和 95 百分位数中,年累积总生产力在一年中达到的时间有早(3 条)和晚(13 条)之分。了解河流生产力趋势的驱动因素将有助于阐明河流食物网的模式以及河流生物地球化学的功能作用。
{"title":"Phenology of gross primary productivity in rivers displays high variability within years but stability across years","authors":"Nicholas S. Marzolf, Michael J. Vlah, Heili E. Lowman, Weston M. Slaughter, Emily S. Bernhardt","doi":"10.1002/lol2.10407","DOIUrl":"10.1002/lol2.10407","url":null,"abstract":"<p>Modeling and sensor innovations in the last decade have enabled routine and continuous estimation of daily gross primary productivity (GPP) for rivers. Here, we generate and evaluate within and across year variability for 59 US rivers for which we have compiled a 14-yr time series of daily GPP estimates. River productivity varied widely across (median annual GPP 462 g C m<sup>−2</sup> yr<sup>−1</sup>, range 19–3445 g C m<sup>−2</sup> yr<sup>−1</sup>) and within rivers (CV<sub>GPP-Inter</sub> 5.7–37.3%). Within this dataset, we found that five rivers have become consistently more productive over time, while 11 rivers have become consistently less productive. Furthermore, trends in ecosystem phenology were identified, where cumulative annual GPP was reached earlier (<i>n</i> = 3) and later (<i>n</i> = 13) in the year across the 25<sup>th</sup>, 50<sup>th</sup>, 75<sup>th</sup>, and 95<sup>th</sup> percentiles. Understanding the drivers of productivity trends in rivers will elucidate patterns in river food webs and the functional role of river biogeochemistry.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 5","pages":"524-531"},"PeriodicalIF":5.1,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Igor Ogashawara, Sabine Wollrab, Stella A. Berger, Christine Kiel, Andreas Jechow, Alexis L. N. Guislain, Peter Gege, Thomas Ruhtz, Martin Hieronymi, Thomas Schneider, Gunnar Lischeid, Gabriel A. Singer, Franz Hölker, Hans-Peter Grossart, Jens C. Nejstgaard
<p>The use of satellite remote sensing for monitoring water quality in inland water systems has been growing in the last decades especially due to the development of new orbital sensors (Kutser et al. <span>2020</span>; Ogashawara <span>2021</span>). Earth observations provide new angles for limnology, such as a universal perspective of multiple aquatic ecosystems simultaneously, regional to global coverage, the potential to acquire time series of data and its valuable input to predictive models. Additionally, it allows the retrieval of several parameters across the surfaces of an increasing number of smaller lakes, providing not only the surface area and elevation, but also surface biogeochemical data. The exponential growth of studies using this technology highlights that the improved computing resources, increased amount of satellite imagery, and development of operational remote sensing algorithms to understand complex inland water systems is now a reality (Topp et al. <span>2020</span>).</p><p>With the increasing access to satellite data, several organizations are developing remote sensing-based products for water quality. These products are currently distributed by national and international agencies (i.e., European Space Agency [ESA], US Geological Survey [USGS]), international programs (i.e., Copernicus Marine, Copernicus Land, and Copernicus Climate Change), academic research (i.e., Minnesota Lake Browser, https://lakes.rs.umn.edu/), and private industry (i.e., CyanoLakes, https://www.cyanolakes.com/; CyanoAlert, https://cyanoalert.com/). Typically, the data behind these products have undergone substantial processing including atmospheric correction, identification of quality issues, and bio-geo-optical algorithms to derive the desired bio-geophysical variables. Figure 1 exemplifies the main procedures for generating a quality controlled remote sensing-based water quality product (inland, coastal, and marine). Procedures are divided into five types: (1) the initial data needed (the Level 1 satellite imagery, the in situ radiometric data, the in situ bio-geo-optical properties [especially inherent optical properties] and in situ water quality curated data); (2) the remote sensing processes (atmospheric correction and bio-geo-optical modeling), 3) the validation processes (of the remote sensing processes using in situ collected data); (4) the remote sensing-based products such as the atmospheric and glint correction imagery; and (5) the water quality products which are produced by applying the selected bio-geo-optical algorithms (locally and seasonally adapted to the dominating water constituents and validated with in situ water quality data) to the atmospherically corrected image. Finally, the remote sensing-based product needs to pass a quality assurance and quality control (QA/QC) to generate a final curated product.</p><p>As presented in Fig. 1, obtaining remote sensing-based water quality products is intricate, particularly for inland
过去几十年来,卫星遥感技术在监测内陆水系水质方面的应用不断增加,特别是由于新型轨道传感器的发展(Kutser 等,2020 年;Ogashawara,2021 年)。对地观测为湖泊学提供了新的视角,如同时观测多个水生生态系统的普遍视角、区域到全球的覆盖范围、获取时间序列数据的潜力及其对预测模型的宝贵投入。此外,它还可以检索越来越多的小型湖泊表面的多个参数,不仅提供表面积和海拔高度,还提供表面生物地球化学数据。利用该技术进行的研究呈指数级增长,这突出表明计算资源的改善、卫星图像数量的增加,以及用于了解复杂内陆水系的实用遥感算法的开发现已成为现实(Topp 等,2020 年)。这些产品目前由国家和国际机构(即欧洲航天局 [ESA]、美国地质调查局 [USGS])、国际项目(即哥白尼海洋、哥白尼陆地和哥白尼气候变化)、学术研究(即明尼苏达湖泊浏览器,https://lakes.rs.umn.edu/)和私营企业(即 CyanoLakes,https://www.cyanolakes.com/;CyanoAlert,https://cyanoalert.com/)分发。通常情况下,这些产品背后的数据都经过大量处理,包括大气校正、质量问题识别和生物地球光学算法,以得出所需的生物地球物理变量。图 1 举例说明了生成基于质量控制的遥感水质产品(内陆、沿岸和海洋)的主要程序。程序分为五类:(1) 所需的初始数据(1 级卫星图像、原位辐射数据、原位生物地理光学特性[特别是固有 光学特性]和原位水质曲线数据);(2) 遥感过程(大气校正和生物地理光学建模);(3) 验证过程(利 用原位采集的数据对遥感过程进行验证);(4) 基于遥感的产品,如大气校正和闪烁校正图像;以及 (5) 水质产品,通过将选定的生物地球光学算法(根据当地和季节的主要水成 分进行调整,并利用现场水质数据进行验证)应用于大气校正图像而生成。最后,基于遥感的产品需要通过质量保证和质量控制(QA/QC),以生成最终的策划产品。如图 1 所示,获得基于遥感的水质产品非常复杂,尤其是对于内陆水域,由于水体中光学活性成分(OACs;即浮游植物色素、有色溶解有机物 [CDOM] 和沉积物)的自然波动很大,这些水域的光学特性变化很大(Ogashawara 等人,2017 年)。为了说明这种复杂性,藻类大量繁殖可表现为富含 CDOM 的褐色水体和引起浑浊的移动沉积物(Lebret 等,2018 年)。由于这种光学复杂性,许多基于遥感技术的海洋颜色产品会掩盖浑浊水域,导致许多淡水系统被排除在外。为促进对遥感技术的利用,并加强对遥感数据使用权衡的理解,本信讨论了(i)导致遥感数据解释问题的主要问题;(ii)误读的后果;以及(iii)建议利用遥感数据的策略,以及有助于可靠校准和验证基于遥感的水质产品的方法。选择遥感产品是湖泊学研究的首要考虑因素之一。基于遥感的产品是为开阔海域(海 洋颜色产品)、沿岸或内陆水域设计的,在做出选择之前,关键是要弄清它们之间的差 别。这些差异源于水体中光的可用性,近似地讲,(1) 开阔海域主要吸收可见光的红色部分,(2) 沿岸水域和清澈的内陆水域吸收蓝光和红光,(3) 浑浊的内陆水域强烈吸收可见光的短波长到红色部分(Kirk,2011 年)。了解光与水之间相互作用的这些变化,有助于在处理遥感数据时决定使用适当的光谱区域,以进行大气校正和生物地球光学建模。 从卫星数据中计算叶绿素 a(Chl a)浓度就是一个强调选择适当光谱区域重要性的例子。由于叶绿素 a 在 440 纳米附近的吸收和极低的 CDOM 背景信号,为开阔海域开发的处理算法依赖于蓝绿光谱带的比值(O'Reilly 和 Werdell,2019 年)。相比之下,沿岸水域产品采用神经网络方法利用整个光谱(Brockmann 等,2016 年),而迄今为止的内陆水域遥感产品通常基于 665 纳米(Chl a 吸收的红色峰值)和 700 纳米(藻类细胞散射,Gitelson,1992 年)附近的红边水生反射率之比进行计算。由于开阔海域的 Chl a 浓度较低,红色范围内的光谱带通常被水吸收,不适合进行 Chl a 采集。在内陆水域(通常存在 CDOM),蓝色光谱带通常被 CDOM 的吸收所主导,掩盖了 440 纳米波长处的 Chl a 吸收,从而有利于使用 665 纳米波长处的 Chl a 吸收。作为比较,最近开发的原位 Chl a 传感器使用红光激发,而不是传统的蓝光激发,以应对沿海和内陆水域的典型光学挑战。此外,必须强调的是,开阔洋、沿岸和内陆水域的 Chl a 遥感产品已针对不同的浓度范围进行了优化,这是在使用数据前应考虑的一个因素。由于不同类型的水与光之间的关系错综复杂,因此了解基于遥感技术的水质产品中的遥感数据处理方法对于了解每种产品的优缺点至关重要。图 2A 展示了不同水生环境中典型的水生反射光谱(遥感反射率)示例,直观地突出了光与水之间的对比交互作用。图 2BD,F 展示了德国东北部梅克伦堡-勃兰登堡湖区(Ogashawara 等人,2021 年)湖泊上空的哨兵 2 号多光谱仪器(MSI)提供的三种基于遥感的 Chl a 产品,以说明选择最适合的方法估算 Chl a 浓度的重要性。我们选择了传统的遥感方法:(i) 开阔海洋(图 2B);(ii) 内陆水域;(iii) 沿海水域(图 2F)。对哨兵 2 号 MSI 图像(场景 ID:GS2A_20190726T102031_021369_N02.08)的这三种不同的遥感产品之间的视觉差异,可通过各自的遥感估算 Chl a 浓度与实验室在同一天使用高效液相色谱法(HPLC)测量的水样 Chl a 浓度的散点图(分别见图 2C、E、G)得到进一步证实。在这些例子中,可以观察到开阔海域方法(图 2C)低估了 Chl a 浓度,内陆水域方法(图 2E)低估了富营养化程度较高水域的 Chl a 浓度,而沿岸方法(图 2G)则低估了所有 Chl a 浓度。这些结果与前文所述一致,即在湖泊中采用开阔海域方法时,由于可见光谱的蓝色和绿 色区域的使用受到 CDOM 的严重影响,其结果可能会严重低估 Chl a 的真实浓度,特别是在 浑浊水域中。这也凸显了使用原位数据验证所选卫星产品的重要性--因为验证过程对质量保证/质量控制至关重要(见图 1)。内陆水域(图 1)遥感数据处理的一大挑战是大气校正(Pahlevan 等,2021 年)。大气校正是在卫星或机载传感器观测地球表面目标的视场中消除大气光学效应的过程。大气校正的一部分是闪烁校正,它可以去除从太阳镜面反射到水面的光以及从天空反射到传感器的光产生的测量信号。卫星测量到的总信号中约有 90% 来自大气层(IOCCG,2010 年),闪烁光的强度可能会高于水面离开辐射的强度,这取决于水的亮度、太阳方位角和波长。因此,水上校正方法的精度要求远高于陆地。图 3 展示了一个富营养化湖泊的平均反射率光谱,该湖泊的哨兵 2 号 MSI 图像未进行大气校正(大气顶反射率-RTOA),使用了陆基大气校正(表面反射率-SR),并在计算遥感反射率 (Rrs) 时使用了水生大气校正。 最近的一项研究对大地遥
{"title":"Unleashing the power of remote sensing data in aquatic research: Guidelines for optimal utilization","authors":"Igor Ogashawara, Sabine Wollrab, Stella A. Berger, Christine Kiel, Andreas Jechow, Alexis L. N. Guislain, Peter Gege, Thomas Ruhtz, Martin Hieronymi, Thomas Schneider, Gunnar Lischeid, Gabriel A. Singer, Franz Hölker, Hans-Peter Grossart, Jens C. Nejstgaard","doi":"10.1002/lol2.10427","DOIUrl":"10.1002/lol2.10427","url":null,"abstract":"<p>The use of satellite remote sensing for monitoring water quality in inland water systems has been growing in the last decades especially due to the development of new orbital sensors (Kutser et al. <span>2020</span>; Ogashawara <span>2021</span>). Earth observations provide new angles for limnology, such as a universal perspective of multiple aquatic ecosystems simultaneously, regional to global coverage, the potential to acquire time series of data and its valuable input to predictive models. Additionally, it allows the retrieval of several parameters across the surfaces of an increasing number of smaller lakes, providing not only the surface area and elevation, but also surface biogeochemical data. The exponential growth of studies using this technology highlights that the improved computing resources, increased amount of satellite imagery, and development of operational remote sensing algorithms to understand complex inland water systems is now a reality (Topp et al. <span>2020</span>).</p><p>With the increasing access to satellite data, several organizations are developing remote sensing-based products for water quality. These products are currently distributed by national and international agencies (i.e., European Space Agency [ESA], US Geological Survey [USGS]), international programs (i.e., Copernicus Marine, Copernicus Land, and Copernicus Climate Change), academic research (i.e., Minnesota Lake Browser, https://lakes.rs.umn.edu/), and private industry (i.e., CyanoLakes, https://www.cyanolakes.com/; CyanoAlert, https://cyanoalert.com/). Typically, the data behind these products have undergone substantial processing including atmospheric correction, identification of quality issues, and bio-geo-optical algorithms to derive the desired bio-geophysical variables. Figure 1 exemplifies the main procedures for generating a quality controlled remote sensing-based water quality product (inland, coastal, and marine). Procedures are divided into five types: (1) the initial data needed (the Level 1 satellite imagery, the in situ radiometric data, the in situ bio-geo-optical properties [especially inherent optical properties] and in situ water quality curated data); (2) the remote sensing processes (atmospheric correction and bio-geo-optical modeling), 3) the validation processes (of the remote sensing processes using in situ collected data); (4) the remote sensing-based products such as the atmospheric and glint correction imagery; and (5) the water quality products which are produced by applying the selected bio-geo-optical algorithms (locally and seasonally adapted to the dominating water constituents and validated with in situ water quality data) to the atmospherically corrected image. Finally, the remote sensing-based product needs to pass a quality assurance and quality control (QA/QC) to generate a final curated product.</p><p>As presented in Fig. 1, obtaining remote sensing-based water quality products is intricate, particularly for inland","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 6","pages":"667-673"},"PeriodicalIF":5.1,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10427","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christoph J. Gey, Laurent Pfister, Guilhem Türk, Frankie Thielen, Loic Leonard, Katharina E. Schmitt, Bernd R. Schöne
Oxygen isotopes in stream water can serve as natural tracers of watershed dynamics. Freshwater pearl mussels provide δ18Owater estimates that overcome temporal and spatial limitations of instrumental records. The reliability of shell-based δ18Owater reconstructions depends on understanding which shell layer biomineralizes closer to oxygen isotopic equilibrium with ambient water. To determine this, both the (outer) prismatic and (inner) nacreous sublayers of the outer shell layer were sampled. Over 2500 isotope values were obtained from shells collected from the Our River (Luxembourg) and from mussels cultured in tanks at constant temperature and monitored δ18Owater. Calculated δ18Owater from the prismatic portion was in excellent agreement with monitored δ18Owater, while δ18Oshell of the nacreous portion was systematically offset by +0.43‰, overestimating δ18Owater by +0.53‰. Although shell portions were formed simultaneously from the same extrapallial fluid, they underwent different fractionation mechanisms, presumably due to differences in carbonic anhydrase activity catalyzing mineralization processes.
{"title":"Biologically driven isotope fractionation in ultrastructurally different shell portions of freshwater pearl mussels (Margaritifera margaritifera): Implications for stream water δ18O reconstructions","authors":"Christoph J. Gey, Laurent Pfister, Guilhem Türk, Frankie Thielen, Loic Leonard, Katharina E. Schmitt, Bernd R. Schöne","doi":"10.1002/lol2.10426","DOIUrl":"10.1002/lol2.10426","url":null,"abstract":"<p>Oxygen isotopes in stream water can serve as natural tracers of watershed dynamics. Freshwater pearl mussels provide δ<sup>18</sup>O<sub>water</sub> estimates that overcome temporal and spatial limitations of instrumental records. The reliability of shell-based δ<sup>18</sup>O<sub>water</sub> reconstructions depends on understanding which shell layer biomineralizes closer to oxygen isotopic equilibrium with ambient water. To determine this, both the (outer) prismatic and (inner) nacreous sublayers of the outer shell layer were sampled. Over 2500 isotope values were obtained from shells collected from the Our River (Luxembourg) and from mussels cultured in tanks at constant temperature and monitored δ<sup>18</sup>O<sub>water</sub>. Calculated δ<sup>18</sup>O<sub>water</sub> from the prismatic portion was in excellent agreement with monitored δ<sup>18</sup>O<sub>water</sub>, while δ<sup>18</sup>O<sub>shell</sub> of the nacreous portion was systematically offset by +0.43‰, overestimating δ<sup>18</sup>O<sub>water</sub> by +0.53‰. Although shell portions were formed simultaneously from the same extrapallial fluid, they underwent different fractionation mechanisms, presumably due to differences in carbonic anhydrase activity catalyzing mineralization processes.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 6","pages":"827-836"},"PeriodicalIF":5.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10426","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141877370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The frequency of news reporting about scientific topics is positively related to public interest as well as to public support for science funding and public policy change. This correlation can also have positive impacts on individual scientific careers depending on the chosen subject area of research. Analysis of a public news database shows the frequency and trends in news reporting of several popular research areas in the aquatic sciences. The frequency of appearance of topics in the news varies over more than three orders of magnitude. Temporal trends in reporting vary from steeply increasing (+25% per year) to declining (−4% per year). Suggestions are offered concerning the framing of research topics and overall better communication of research findings to journalists and the general public. This understanding may increase news prominence, public interest, science funding, and policy change in aquatic research areas.
{"title":"What's hot and what's not in the aquatic sciences—Understanding and improving news coverage","authors":"John A. Downing","doi":"10.1002/lol2.10425","DOIUrl":"10.1002/lol2.10425","url":null,"abstract":"<p>The frequency of news reporting about scientific topics is positively related to public interest as well as to public support for science funding and public policy change. This correlation can also have positive impacts on individual scientific careers depending on the chosen subject area of research. Analysis of a public news database shows the frequency and trends in news reporting of several popular research areas in the aquatic sciences. The frequency of appearance of topics in the news varies over more than three orders of magnitude. Temporal trends in reporting vary from steeply increasing (+25% per year) to declining (−4% per year). Suggestions are offered concerning the framing of research topics and overall better communication of research findings to journalists and the general public. This understanding may increase news prominence, public interest, science funding, and policy change in aquatic research areas.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 6","pages":"674-682"},"PeriodicalIF":5.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10425","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eric J. Raes, Shannon Myles, Liam MacNeil, Matthias Wietz, Christina Bienhold, Karen Tait, Paul J. Somerfield, Andrew Bissett, Jodie van de Kamp, Josep M. Gasol, Ramon Massana, Yi-Chun Yeh, Jed A. Fuhrman, Julie LaRoche
Understanding the patterns of marine microbial diversity (Bacteria + Archaea) is essential, as variations in their alpha- and beta-diversities can affect ecological processes. Investigations of microbial diversity from global oceanographic expeditions and basin-wide transects show positive correlations between microbial diversity and either temperature or productivity, but these studies rarely captured seasonality, especially in polar regions. Here, using multiannual alpha-diversity data from eight time series in the northern and southern hemispheres, we show that marine microbial community richness and evenness generally correlate more strongly with daylength than with temperature or chlorophyll a (a proxy for photosynthetic biomass). This pattern is observable across time series found in the northern and southern hemispheres regardless of collection method, DNA extraction protocols, targeted 16S rRNA hypervariable region, sequencing technology, or bioinformatics pipeline.
{"title":"Seasonal patterns of microbial diversity across the world oceans","authors":"Eric J. Raes, Shannon Myles, Liam MacNeil, Matthias Wietz, Christina Bienhold, Karen Tait, Paul J. Somerfield, Andrew Bissett, Jodie van de Kamp, Josep M. Gasol, Ramon Massana, Yi-Chun Yeh, Jed A. Fuhrman, Julie LaRoche","doi":"10.1002/lol2.10422","DOIUrl":"10.1002/lol2.10422","url":null,"abstract":"<p>Understanding the patterns of marine microbial diversity (Bacteria + Archaea) is essential, as variations in their alpha- and beta-diversities can affect ecological processes. Investigations of microbial diversity from global oceanographic expeditions and basin-wide transects show positive correlations between microbial diversity and either temperature or productivity, but these studies rarely captured seasonality, especially in polar regions. Here, using multiannual alpha-diversity data from eight time series in the northern and southern hemispheres, we show that marine microbial community richness and evenness generally correlate more strongly with daylength than with temperature or chlorophyll <i>a</i> (a proxy for photosynthetic biomass). This pattern is observable across time series found in the northern and southern hemispheres regardless of collection method, DNA extraction protocols, targeted <i>16S</i> rRNA hypervariable region, sequencing technology, or bioinformatics pipeline.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 5","pages":"512-523"},"PeriodicalIF":5.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10422","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141726120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evangeline Fachon, Robert S. Pickart, Gay Sheffield, Emma Pate, Mrunmayee Pathare, Michael L. Brosnahan, Eric Muhlbach, Kali Horn, Nathaniel N. Spada, Anushka Rajagopalan, Peigen Lin, Leah T. McRaven, Loreley S. Lago, Jie Huang, Frank Bahr, Dean A. Stockwell, Katherine A. Hubbard, Thomas J. Farrugia, Kathi A. Lefebvre, Donald M. Anderson
In recent years, blooms of the neurotoxic dinoflagellate Alexandrium catenella have been documented in Pacific Arctic waters, and the paralytic shellfish toxins (PSTs) that this species produces have been detected throughout the food web. These observations have raised significant concerns about the role that harmful algal blooms (HABs) will play in a rapidly changing Arctic. During a research cruise in summer 2022, a massive bloom of A. catenella was detected in real time as it was advected through the Bering Strait region. The bloom was exceptional in both spatial scale and density, extending > 600 km latitudinally, reaching concentrations > 174,000 cells L−1, and producing high-potency PST congeners. Throughout the event, coastal stakeholders in the region were engaged and a multi-faceted community response was mobilized. This unprecedented bloom highlighted the urgent need for response capabilities to ensure safe utilization of critical marine resources in a region that has little experience with HABs.
{"title":"Tracking a large-scale and highly toxic Arctic algal bloom: Rapid detection and risk communication","authors":"Evangeline Fachon, Robert S. Pickart, Gay Sheffield, Emma Pate, Mrunmayee Pathare, Michael L. Brosnahan, Eric Muhlbach, Kali Horn, Nathaniel N. Spada, Anushka Rajagopalan, Peigen Lin, Leah T. McRaven, Loreley S. Lago, Jie Huang, Frank Bahr, Dean A. Stockwell, Katherine A. Hubbard, Thomas J. Farrugia, Kathi A. Lefebvre, Donald M. Anderson","doi":"10.1002/lol2.10421","DOIUrl":"10.1002/lol2.10421","url":null,"abstract":"<p>In recent years, blooms of the neurotoxic dinoflagellate <i>Alexandrium catenella</i> have been documented in Pacific Arctic waters, and the paralytic shellfish toxins (PSTs) that this species produces have been detected throughout the food web. These observations have raised significant concerns about the role that harmful algal blooms (HABs) will play in a rapidly changing Arctic. During a research cruise in summer 2022, a massive bloom of <i>A. catenella</i> was detected in real time as it was advected through the Bering Strait region. The bloom was exceptional in both spatial scale and density, extending > 600 km latitudinally, reaching concentrations > 174,000 cells L<sup>−1</sup>, and producing high-potency PST congeners. Throughout the event, coastal stakeholders in the region were engaged and a multi-faceted community response was mobilized. This unprecedented bloom highlighted the urgent need for response capabilities to ensure safe utilization of critical marine resources in a region that has little experience with HABs.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"10 1","pages":"62-72"},"PeriodicalIF":5.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10421","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141584296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bacteria and macroalgae share an inseparable relationship, jointly influencing coastal ecosystems. Within macroalgae habitats, Planctomycetota, a group of bacteria notoriously challenging to cultivate, often dominate. However, the mechanisms facilitating their persistence in this environment remain unclear. Here, we successfully isolated a novel Planctomycetota bacterium, Stieleria sp. HD01, from the surface of kelp. We demonstrated that HD01 possesses a robust ability to metabolize fucoidan, which constitutes half of the kelp-derived organic carbon and exhibits resistance to attack by most microorganisms. Moreover, HD01 can utilize a broad spectrum of other organics, indicating its metabolic versatility and competitive prowess within algal environments. Additionally, HD01 can secrete antagonistic substances against other bacteria, form biofilms, and employ superoxide dismutase and catalase to resist oxidative stress, further consolidating its ecological fitness. Comparative metagenomics analysis suggested that Planctomycetota may have a mutually beneficial relationship with kelp.
{"title":"Adaptive traits of Planctomycetota bacteria to thrive in macroalgal habitats and establish mutually beneficial relationship with macroalgae","authors":"Xueyan Gao, Yihua Xiao, Ziwei Wang, Hanshuang Zhao, Yufei Yue, Shailesh Nair, Zenghu Zhang, Yongyu Zhang","doi":"10.1002/lol2.10424","DOIUrl":"10.1002/lol2.10424","url":null,"abstract":"<p>Bacteria and macroalgae share an inseparable relationship, jointly influencing coastal ecosystems. Within macroalgae habitats, <i>Planctomycetota</i>, a group of bacteria notoriously challenging to cultivate, often dominate. However, the mechanisms facilitating their persistence in this environment remain unclear. Here, we successfully isolated a novel <i>Planctomycetota</i> bacterium, <i>Stieleria</i> sp. HD01, from the surface of kelp. We demonstrated that HD01 possesses a robust ability to metabolize fucoidan, which constitutes half of the kelp-derived organic carbon and exhibits resistance to attack by most microorganisms. Moreover, HD01 can utilize a broad spectrum of other organics, indicating its metabolic versatility and competitive prowess within algal environments. Additionally, HD01 can secrete antagonistic substances against other bacteria, form biofilms, and employ superoxide dismutase and catalase to resist oxidative stress, further consolidating its ecological fitness. Comparative metagenomics analysis suggested that <i>Planctomycetota</i> may have a mutually beneficial relationship with kelp.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 6","pages":"745-753"},"PeriodicalIF":5.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10424","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141584425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Danielle K. Hare, Ashley M. Helton, Carolyn S. Cummins, Phillip M. Bumpers, Nathan J. Tomczyk, Phoenix A. Rogers, Seth J. Wenger, Erin R. Hotchkiss, Amy D. Rosemond, Jonathan P. Benstead
Leaf litter dominates particulate organic carbon inputs to forest streams. Using data-informed simulations, we explored how litter type (slow- vs. fast-decomposing species), pulsed autumn litter inputs, groundwater-mediated temperature regimes, and climate warming affect litter breakdown in a 3rd-order stream network. We found that the time-dependent interactions of these variables govern network-scale litter breakdown phenology, with greater thermal sensitivity of slow-decomposing litter for both current and future scenarios. Groundwater thermal inputs modified litter breakdown phenology by reducing spring and summer and elevating winter litter breakdown fluxes. Under future warming scenarios, the source depth of contributing groundwater influenced summer detrital resources; shallow groundwater-fed streams had reduced summer resources compared to deep groundwater-fed streams. Our results demonstrate that predicting in-stream carbon cycling requires explicit consideration of the phenology of resource inputs and the seasonal timing of environmental factors, notably stream thermal regimes.
{"title":"Leaf litter breakdown phenology in headwater stream networks is modulated by groundwater thermal regimes and litter type","authors":"Danielle K. Hare, Ashley M. Helton, Carolyn S. Cummins, Phillip M. Bumpers, Nathan J. Tomczyk, Phoenix A. Rogers, Seth J. Wenger, Erin R. Hotchkiss, Amy D. Rosemond, Jonathan P. Benstead","doi":"10.1002/lol2.10423","DOIUrl":"10.1002/lol2.10423","url":null,"abstract":"<p>Leaf litter dominates particulate organic carbon inputs to forest streams. Using data-informed simulations, we explored how litter type (slow- vs. fast-decomposing species), pulsed autumn litter inputs, groundwater-mediated temperature regimes, and climate warming affect litter breakdown in a 3<sup>rd</sup>-order stream network. We found that the time-dependent interactions of these variables govern network-scale litter breakdown phenology, with greater thermal sensitivity of slow-decomposing litter for both current and future scenarios. Groundwater thermal inputs modified litter breakdown phenology by reducing spring and summer and elevating winter litter breakdown fluxes. Under future warming scenarios, the source depth of contributing groundwater influenced summer detrital resources; shallow groundwater-fed streams had reduced summer resources compared to deep groundwater-fed streams. Our results demonstrate that predicting in-stream carbon cycling requires explicit consideration of the phenology of resource inputs and the seasonal timing of environmental factors, notably stream thermal regimes.</p>","PeriodicalId":18128,"journal":{"name":"Limnology and Oceanography Letters","volume":"9 5","pages":"532-542"},"PeriodicalIF":5.1,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lol2.10423","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141545774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}