作者开发使用我们的沃尔特·博因顿和皮特Sampou和协同工作对反硝化与托德假名在马里兰中心的大学环境科学开展工作，观察这种方法。我们的脱氮方法的发展不会没有支持兰州海助学计划和美国国家科学基金会是不可能的。这里使用的具有代表性的数据收集与兰州海格兰特（R / AQ-5C）和编写工作的资金由兰州海格兰特得到了支持（R / SV-2），诺阿切萨皮克湾办公室（NA13NMF4570210），牡蛎恢复合作伙伴，美国国家科学基金会（OCE1427019），艾斯能公司和马里兰环境服务/马里兰州港口管理局。

注:不受干扰的沉积物 - 水界面内核的集合是使交换良好的实验测量非常重要;高度不安的核心是可能与覆水交换孔隙水溶质和已通过的Fe（II）的氧化和还原硫化合物增强氧气摄取。在本文中，我们强调沉积物的沉积孵化程序只用粗略列入沉积物取样技术和溶质和气体的化学分析。在采样前，或根据初步结果，由整个项目的需求，统计设计或小尺度空间变异预计量确定复制的程度。重复的核心是由许多研究和式三份使用的最小是允许一个更好的统计分析是有用的。 1.沉积物收集处理注:泥沙交流实验的集合使用1）内核USI的手动插入进行纳克潜水员或在浅水或湿地，通过涉水，2）极点用铝杆用手动关闭阀以保持沉积物核化，或3）框核化。 <ol><li>在每个站点，利用GPS记录现场位置，确定底部水中的氧气，温度和盐度使用水质探头，并确定在表面和底部的光合有效辐射（PAR），使用PAR传感器/米。 <ol><li>降低水质探头至〜1米沉积物以上并记录底水特性（深度，温度，溶解氧，温度和盐度/电导率）。 </li><li>降低与水下探头采用降低帧沉积物 - 水界面PAR传感器。比较沉积物表面的PAR读数立即空气 - 水界面下方附近的PAR读数来估计环境光条件下的光的衰减。 </li><li>部署一个盒子取样器在船/船舷，降低它慢慢地减少干扰在穿透沉积物。检查可见干扰或过度悬浮芯盒。 <ol><li>为一个盒子取样器，插入芯管进入沉积物，并使用丁基塞子覆盖芯的顶部。对于通量实验，而核心内的泥沙理想/水平衡水15厘米至15cm泥沙，粗或高度压缩的沉积物收集沉渣少深度是一个可以接受的结果。如果氧气消耗率过高，转移向更水柱高度的平衡。 </li><li>通常使用6.35厘米内径内核的深水研究和底栖用微藻或大型动物种群的沉积物时，采用10厘米内径核心。主要限制到芯尺寸，以覆盖芯的底部的能力。 </li><li>盖上底部具有嵌入O型环的丙烯酸底板。直到有足够的重复收集重复此过程。随着极取样器，首先丙烯酸底板在核心里NER，请从取样器的核心，并添加制动器。 </li></ol></li></ol></li><li>地方内核在充斥着从现场环境水高大隔热水冷却器;这有助于保持原位温度。确保冷却器保持直立。丢弃在运输过程中受到干扰的核心。 </li><li>泵沉积物表面附近考虑到20升大玻璃瓶在实验使用底水。使用隔膜泵以10-20升/分钟的容量或高速蠕动泵。 <ol><li>在浅水​​不分层的水，在水中"扣篮"，它填补了坛中。使用高容量墨盒内联过滤器底部的水过滤可与水柱摄氧量或光合作用（在光）的高速率的网站是有用的，从水柱减少校正只控制核心。 </li></ol></li><li>尽可能快地运输的内核孵化设施。在扩展传输，爱尔兰的情况下，OBIC内核可以成为缺氧和人工鼓泡或流通是必要的。 </li></ol> 2.初始设置<ol><li>在温育设施，在温育浴盆地方芯无论是在一个环境室具有受控的温度，或与通过加热/冷却循环温度控制的双壁培养箱。将温度设置在1.1.1测量底水的温度。 </li><li>加入底水的孵化器，完全淹没沉积物岩芯。另外加水至5升大玻璃瓶与将用于分配更换水套管。 </li><li>一个仅水芯（无沉淀）添加到孵化器。使用水柱坯料是在大多数环境中重要的，以补偿影响气体和溶质任何水柱进程。脱硝的测定中，这些毛坯可以反映不仅水柱过程，但气体的与芯的丙烯酸壁的交换。 </li><li>泡泡核心W¯¯最少2小时的第i个空，以保证热平衡，上覆水满充氧。他们可能在一夜之间保持和时间的课程，第二天早上开始。较长预孵育期尚未评估功效。 <ol><li>对于通风，使用一个小的"T"起泡包括½"具有三路光耦PVC管; 1/8"管插入到T结果在水夹带的底部向上冒泡过程中，而不是确保只有充氧，但在孵化桶与水的芯的水的循环。 </li></ol></li></ol> 3.沉积物 - 水孵化程序<ol><li>检查温度后，以确保它的现场条件相匹配时，附加陀螺到芯的顶部。此时，密封件从水箱水的核心。留在这个过程中的核心打开取样阀。手动从纺丝顶部的底侧轻轻扫任何气泡。 </li><li> ELE瓦泰岛置换水大玻璃瓶〜30-40比孵育芯的顶部更高厘米和漏线向下，以消除在该行的任何空气。尽管仍然流淌，附加线的核心顶部，并关闭阀门。 </li><li>打开中央搅拌转盘和每分钟调整旋转速度，使得芯旋转〜40倍，或者在足以混合水柱但不重悬沉淀的速率。 </li><li>大约所有内核被密封5分钟后，打开更换水阀和样品阀门，再短管件连接到用路厄接头的样品阀。放置此采样管中有7毫升玻璃管，其被填充到溢出的底部。前封盖的管中，加入10微升为30g L -1升汞2作为防腐剂。 <ol><li>在温度接近培养温度水下存储这些样品。其他实验室已经成功地使用12毫升"测试瓶"山姆PLE存储。 </li></ol></li><li>对于溶质采样，附加20毫升注射器筒的取样阀，并打开更换水阀。注射器筒进行填充，直到完全只使用重力。附加一个柱塞和一个过滤器上，然后将样品过滤到小瓶中。这些样品用于养分分析被冻结在-20 °C，直到分析。 注意:取样的在黑暗中的时间过程通常涉及与范围从0.5至&gt; 2小时取样之间的间隔4个采样周期，这取决于氧摄取速率。随着吸氧量低利率，时间间隔长;在呼吸率高的沉积物中，需要的时间间隔要短。样品的过高卷在每个采样点取可能导致采样太大整个样品体积的比例;在我们的工作，这些样本量导致微不足道的修正。如果样品的更大体积是需要的，直径较大的芯或增加的水柱高度可能是必要的。 </li><li>不低于50％的氧气耗尽的阈值的采样的时间过程继续进行，以25％的氧损耗一般在营养物浓度提供足够的信号。在这里，使用校准光极氧气浓度和血氧饱和度的直接分析。 <ol><li>如果沉积物由浅，光照的环境中，在第4 次采样，开灯，并采取3后续样品。注意，在高度光合沉积物，O 2和气泡形成的过饱和限制在某些情况下，气体流量的测量。氧的持续监控是一个日益可行的和有价值的替代，与具有相对小的探针高度可靠和精确的光纤的测量技术。 </li></ol></li><li>在沉积物孵育结束时，任一测量水柱的高度或在虹吸水柱量筒直接determ的INE水量，并采取每个核心的照片。 </li></ol> 4.样品分析<ol><li>用于分析的N 2，O 2和Ar为膜泵样品入口质谱仪，和确定的N 2的比例:Ar和O 2的Ar为&lt;0.03％的精度12,23。 <ol><li>耦合的四极质谱仪的膜入口。推样品到使用蠕动泵在膜管。收集样品浪费在一个塑料瓶子和治疗为化学废物，由于汞防腐剂。与保温温度与空气平衡的去离子水进行校准。 </li></ol></li><li>执行手动营养分析了≤5毫升样品或使用自动分析仪更小的体积。当样品解冻，立即开始分析。营养素分析程序的选择必须产生足够的孵育期间观察养分浓度变化的精度。典型的检测限制是&lt;0.05微摩尔L -1和时间进程的发展趋势是很困难都极低和极高的营养浓度下观察。 <ol><li>对于可溶性活性磷的比色分析，使用抗坏血酸磷的技术。对于铵分析，利用使用苯酚次氯酸盐试剂24一朝一夕的显色。自动比色分析，无论是使用分段流程或离散分析仪，是一个伟大的选择和利用较低的样品体积。 </li><li>对于加硝酸亚硝酸盐的分析，利用隔夜显色用氯化钒作为还原剂25，或使用自动分析仪</li><li>比较上的U​​V / VIS分光光度计对标准曲线求出的吸光度，并从标准浓度和吸光度的回归确定的浓度。 </li></ol></li></ol> 5.计算沉积物 - 水汇率<ol><li>倒退气体或营养物质的浓度随时间独立完成黑暗和照明孵育，用斜率表示为微摩尔L -1 -1。纠正孵育芯的斜坡用于水仅列型磁芯的斜率。只可使用计算显著回归（P &lt;0.05）;在最后的数据的电子表格识别非显著数据。 </li><li>从化学成分的浓度上覆水的变化斜率计算沉积物 - 水汇率: <img alt="式（1）" src="/files/ftp_upload/54098/54098equation1.jpg" /> 其中，F是通量（微摩尔米-2小时-1），ΔC/Δt为上覆水的浓度变化（微摩尔L -1小时-1）的斜率，V是覆水（升）的体积和A是保温芯（米-2）的区域。为了估计每日光通量，乘以光小时照明率并加入了黑暗率乘以黑夜时间。 </li></ol> 6.报告<ol><li>在报告从沉积物 - 水交换测量结果提供足够的信息供其他科学家理解已采样的环境。必要的信息，包括:1）位点的位置和水深，2）的物理特性如场和孵化温度，和PAR，3）底部的水的特性，如氧，营养物浓度和盐度，和4）沉淀特性，诸如晶粒尺寸，有机物浓度和底栖动物的存在。 </li></ol>

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Mar. Biol. Ecol. 122, 63-81 (1988).</li><li>Petersen, J. E., Cornwell, J. C., Kemp, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implicit+scaling+in+experimental+enclosed+aquatic+ecosystems.">Implicit scaling in experimental enclosed aquatic ecosystems.</a> Oikos. 85, 3-18 (1999).</li><li>Kana, T. M., Weiss, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comment+on+"Comparison+of+isotope+pairing+and+N-2+:+Ar+methods+for+measuring+sediment+denitrification"+by+B.+D.+Eyre,+S.+Rysgaard,+T.+Daisgaard,+and+P.+Bondo+Christensen.+2002.+Estuaries+25:+1077-1087.">Comment on "Comparison of isotope pairing and N-2 : Ar methods for measuring sediment denitrification" by B. D. Eyre, S. Rysgaard, T. Daisgaard, and P. Bondo Christensen. 2002. Estuaries 25: 1077-1087.</a> Estuaries. 27, 173-176 (2004).</li><li>Parsons, T. R., Maita, Y., Lalli, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> A Manual of Chemical and Biological Methods for Seawater Analysis. , (1984).</li><li>Doane, T. A., Horwath, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectrophotometric+determination+of+nitrate+with+a+single+reagent.">Spectrophotometric determination of nitrate with a single reagent.</a> Analytical Letters. 36, 2713-2722 (2003).</li><li>Testa, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+the+impact+of+floating+oyster+(Crassostrea+virginica)+aquaculture+on+sediment-water+nutrient+and+oxygen+fluxes.">Modeling the impact of floating oyster (Crassostrea virginica) aquaculture on sediment-water nutrient and oxygen fluxes.</a> Aquac. Environ. Interact. 7, 205-222 (2015).</li><li>Hamme, R. C., Emerson, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+solubility+of+neon,+nitrogen+and+argon+in+distilled+water+and+seawater.">The solubility of neon, nitrogen and argon in distilled water and seawater.</a> Deep-Sea Res. Part I-Oceanogr. Res. Papers. 51, 1517-1528 (2004).</li><li>Chong, L. S., Prokopenko, M. G., Berelson, W. M., Townsend-Small, A., McManus, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitrogen+cycling+within+suboxic+and+anoxic+sediments+from+the+continental+margin+of+Western+North+America.">Nitrogen cycling within suboxic and anoxic sediments from the continental margin of Western North America.</a> Marine Chemistry. 128, 13-25 (2012).</li><li>Eyre, B. D., Rysgaard, S., Dalsgaard, T., Christensen, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+isotope+pairing+and+N-2+:+Ar+methods+for+measuring+sediment-denitrification-assumptions,+modifications,+and+implications.">Comparison of isotope pairing and N-2 : Ar methods for measuring sediment-denitrification-assumptions, modifications, and implications.</a> Estuaries. 25, 1077-1087 (2002).</li><li>Lee, D. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Effects+of+Oxygen+Transition+on+Community+Respiration+and+Potential+Chemoautotrophic+Production+in+a+Seasonally+Stratified+Anoxic+Estuary.">The Effects of Oxygen Transition on Community Respiration and Potential Chemoautotrophic Production in a Seasonally Stratified Anoxic Estuary.</a> Estuar.Coasts. 38, 104-117 (2015).</li><li>MacIntyre, H. L., Geider, R. J., Miller, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microphytobenthos:+The+ecological+role+of+the+"secret+garden"+of+unvegetated,+shallow-water+marine+habitats+.1.+Distribution,+abundance+and+primary+production.">Microphytobenthos: The ecological role of the "secret garden" of unvegetated, shallow-water marine habitats .1. Distribution, abundance and primary production.</a> Estuaries. 19, 186-201 (1996).</li><li>Aller, R. C., Mackin, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Open-incubation,+diffusion+methods+for+measuring+solute+reaction+rates+in+sediments.">Open-incubation, diffusion methods for measuring solute reaction rates in sediments.</a> J. Mar. Res. 47, 411-440 (1989).</li></ol>

作者什么都没有透露。

这里所描述的技术已经被应用到无数种水生系统，浅层和深层的，我们已经发现它在大多数情况下很好地工作。这种方法是改编自他的同事利用，并在文献中提出的方法;它是通过膜进口质谱法脱硝的测量进行了优化。这种方法的优势之一是可以同时处理大量核心的能力。复制具有重复或三次铁心各部位增加测量的信心，虽然另一种方法是，以最大限度地与较少的复制位点，在这些情况下对环境段的平均值可能更代表性质的变异性的。为阐明季节差异，在较少数量的位点的测量的时间序列可以是一个有用的策略。 在这个协议中，有几个关键的步骤。派拉蒙制作小号uccessful测量是具有完整沉积物 - 水界面芯的集合。虽然拒绝不符合这个标准在现场可累核心，核心不佳会导致精度差和精度。保持有氧核心曝气接近原始采集的温度会减少伪和保持健康的，完整的微生物和后生动物种群。最后，对于O 2和N 2的样品，在加入氯化汞防腐剂是至关重要的。我们已经观察到保护气体样品的不当，包括小瓶的过度加热和冷却，可以妥协这些通量测量。其他实验室已经成功地采用7.0μm的氯化锌为毒性较低的防腐剂有降低废物处理成本;对于一个7毫升样品30微升加入是合适的。 的N 2和Ar的比率的准确和精确的分析是关键的N 2的测定</sUB&gt;通量。观察N 2:氩比变化的氧浓度导致一些研究者主张之前分析除氧的功能，一般采用加热铜28。在我们的实验室中使用的仪器是用来确定氧气对N 2的效果:氩比23和效果被发现是非常小的，&lt;0.03％为适度氧气耗尽。在方法上的差异，以评估氧 ​​"效应"的出现由不同的研究者23,28,29导致不同的结论。在N 2大氧效应:氩比会导致N 2 -N外流错误率高;根据我们的经验，我们有可以忽略不计N多观察下氧气消耗率高2 -N流出。在实验室中，在N 2中的氧作用:氩比出现大面积，一个有用的方法是使用电极或光极和氧气浓度氧的独立测量使用内联加热铜从质谱分析的去除。 故障排除这种技术只有在泥沙通量数据的检查是可能的。关键因素时要考虑的回归是穷人搅拌是否是连续的，样品收集和保存正确，以及是否课程时间太短，让低利率的估计。实验的长度一般由氧气时间过程设置，与需要较长的温育以增加信号嵌入在时间过程回归信噪比代谢率较低。氧气生产率高的能产生O 2气泡使气体通量困难，但溶质通量可能会受到影响。 有必要了解这种方法的局限性。小芯覆盖平方米0.3％和较大的芯覆盖0.6％。在与仪表刻度大幅异质性，动画的异构​​分布的站点ALS或植物可以表明一个或两个芯可以不是足够的代表性。也有呈现测量的困难某些环境。脱硝的测定中，甲烷或氧的气泡的存在可能失效的技术中，用N 2:氩比由气体进入气泡的差动掺入的影响。在沉积物底栖微藻殖民的氧气泡的结果相对于氩N 2，和下降的优惠剥离的N 2的形成:氩比。一般情况下，我们不能在那里形成气泡点测量脱硝。厌氧环境带来不同的挑战以及核心曝气在沉积物 - 水界面改变了氧化还原动态。我们查封搅拌上衣核心采集后立即开始通量没有完全更换30水柱。我们与照明沉积物实验通常已经饱和或接近saturatING照明31的水平，以及由此最大化底栖微藻的效果。 沉积物 - 水交换测量跨越沉积物 - 水界面材料的净通量的测量。然而，这些测量单独往往不能识别控制这些界面交流的机制。如果研究的问题包括了解的机制，对有机物反应等信息，终端电子受体区划，bioirrigation和生物扰动和光合生物可能是必要的。建模工作7可能需要孔隙水化学，有机物质反应32直接措施，动物种群的枚举，沉积物生物灌溉，泥沙堆积，或氧化还原或覆水化学13的实验操作的决心。在我们的研究中，良好的沉积物 - 水交换数据是水体沉积物的化学性质理解的重要组成部分，并与其它测量一起，确定了水生生物地球化学循环沉淀回收过程中的作用。 小心关于泥沙处理，温度控制和水柱混合，核心的孵化是溶质和气体在沉积物 - 水界面交换的估计一个有用的方法。然而，在这里所使用的技术，可能需要修改为某些环境和困难的物流，如温育之前延长的时间段。到目前为止，我们已经成功地应用这个孵化方法河口，海岸，湿地，湖泊，水库，河流和池塘保留以最小的修改环境。

沉积物是水生生态系统的生物地球化学的关键组成部分，往往是营养物质和污染物的重要汇。营养，天然气和过渡金属中的生物地球化学湖泊沉积物的开创性研究表明溶质和气体与覆水的均有不同氧化还原条件1,2泥沙交换。对营养元素，沉积物可以是磷源以及有机物质再矿化后固定氮，和在非光合环境3,4-氧水槽。沉水植物，藻类和底栖微藻光合作用可以对溶解物质穿过沉积物-水界面5,6交流深远的影响。 整个沉积物 - 水界面溶质和气体交换的测量进行了两个基础科学和应用科学的目的，包括工程和科学笏校准ER模型质量7,8。这些方法的目标，以尽最大可能，是提供可靠和准确的沉积物 - 水汇率。各种各样的方法已被用来评估在沉积物 - 水界面化学交换。在分层系统中的气体和溶质的底部积水可能是有用的9，但不适用于上述温跃层或pycnoclines沉积物-水交换。涡度相关要求的气体，一般氧，垂直水流速度的高频率测量相结合的高频测量;这种技术具有巨大希望，但是目前还不能提供用于物质交换研究的数据， 在原位圆顶或腔室是一个高度优选的方法中，有覆盖的沉积物的较大表面面积，并在保持原位的温度下，深水压力和光的水平的优点10。在实践中，这些都是非常昂贵的测量，需要大量的时间在更大的研究船;大多数应用程序是更深层次的沿海地带或海洋沉积物。通过使用流动室是达到稳态的核心孵化技术是非常适合孵育11时，保持相对恒定的覆水化学，包括氧气。因为速度由流入和流出的水​​，并且通过水兑换率之间浓度差在稳定状态下确定的，这些孵育可能需要相当长的时间。 我们实验室所用的时间过程的核心孵化方法改编自一些在北美和欧洲不同的实验室所采用的方法，并没有在此基础上一般做法相当数量的文学作品。我们适于这种方法的N 2的测量-N通量12，通常被称为反硝化，并将它施加到光合和非光合沉淀环境，包括estuarie第13条 ，湖泊，水库，湿地和14。通过这些研究，我们发现在我们的整体方法很奏效许多环境中，有的在它没有。反硝化的测量在许多不同的陆地和水生环境中进行了，因为这个过程代表氮的生态系统的重要损失。许多方法已经用于使反硝化测量，一些直接和一些间接的15。直接N 2通量测量是非常困难的，因为大气中高含量的N 2，和随后的高浓度溶解于水16。两种方法已成为具有环境有关率的最佳表现:以N同位素配对同位素17和N 2:在我们的实验室中使用氩气的比例。同位素配对方法已在许多环境中成功应用，在低利率极高的灵敏度。我们利用N2:因为它的简单氩比例的做法，因为它在影响环境足够敏感，我们经常研究。 在本文中，我们将介绍我们已经使用在过去的二十年里，使气体和溶质的沉积物 - 水交换的测量技术方法。沉积物 - 水交换任何测量需要考虑到现场条件和一些实验参数。这些因素包括温度，光照/黑暗条件下18，混合/物理的沉积物-水界面流动19，溶解氧浓度20，这是取得良好测量的关键要素等因素的影响。例如，如果内核从中得到足够的光照底栖微藻的生长地区采集，有必要制定实验，包括黑暗和光照条件下21。同样，加入含氧覆水至缺氧核心不复制的现场条件。水生生态系统可能导致不可避免的工件22的任何部分的实验外壳;这是至关重要的）在沉积物 - 水交换测量程序1所采用的方法识别控制每一种生态系统沉积物 - 水交换的因素; 2）尽量减少实验操作衍生文物。

<table border="0" cellpadding="0" cellspacing="0" width="638">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="64">
			<td height="64" style="height:64px;width:179px;">Multiparameter sonde - temperature, oxygen, salinity</td>
			<td style="width:135px;">YSI</td>
			<td style="width:123px;">&#34;</td>
			<td style="width:203px;">Any high quality equipment will suffice</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">PAR Measurement</td>
			<td style="width:135px;">Li-Cor</td>
			<td align="right" style="width:123px;">6050000</td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Pole corer</td>
			<td style="width:135px;"></td>
			<td style="width:123px;"></td>
			<td style="width:203px;">Built by machine shop</td>
		</tr>
		<tr height="49">
			<td height="49" style="height:49px;width:179px;">Box corer</td>
			<td style="width:135px;">DK-Denmark</td>
			<td style="width:123px;">HAPS Corer</td>
			<td style="width:203px;">We also use light box coring equipment</td>
		</tr>
		<tr height="67">
			<td height="67" style="height:67px;width:179px;">Small core tubes with o-ring fitted bottom, 3&#39; OD, 2.5&#39; Id.</td>
			<td style="width:135px;">various plastics companies</td>
			<td style="width:123px;"></td>
			<td style="width:203px;">Clear acrylic</td>
		</tr>
		<tr height="67">
			<td height="67" style="height:67px;width:179px;">Medium core tubes with o-ring, 4.5&#34; od, 4&#34; id</td>
			<td style="width:135px;">various plastics companies</td>
			<td style="width:123px;"></td>
			<td style="width:203px;">Clear acrylic</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Butyl stopper size 13.5</td>
			<td style="width:135px;">generic</td>
			<td style="width:123px;"></td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Stirring turntable</td>
			<td style="width:135px;"></td>
			<td style="width:123px;"></td>
			<td style="width:203px;">Built by machine shop</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Incubation tub</td>
			<td style="width:135px;"></td>
			<td style="width:123px;"></td>
			<td style="width:203px;">Built by machine shop</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Replacement water carboy</td>
			<td style="width:135px;">Nalgene</td>
			<td style="width:123px;">2320-0050</td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">7 mL glass stoppered tube</td>
			<td style="width:135px;">Chemglass</td>
			<td style="width:123px;">not on inventory</td>
			<td style="width:203px;">&#34;Exetainers&#34; used by other labs</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">20 mL plastic syringe</td>
			<td style="width:135px;">generic</td>
			<td style="width:123px;"></td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Syringe filters</td>
			<td style="width:135px;"></td>
			<td style="width:123px;"></td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:179px;">Plastic tubing</td>
			<td style="width:135px;">Tygon</td>
			<td style="width:123px;">ACF00004-CP</td>
			<td style="width:203px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:179px;">Compact Fluorescent Lights</td>
			<td style="width:135px;">Apollo Horticulture</td>
			<td style="width:123px;">CFL 8U 250W</td>
			<td style="width:203px;"></td>
		</tr>
	</tbody>
</table>

the benthic exchange of o2, n2 and dissolved nutrients using small core incubations

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in nutrient and gas cycles. After cores with intact sediment-water interfaces are collected, they are submerged in incubation tanks and kept under aerobic conditions at in situ temperatures. To initiate a time course of overlying water chemistry, cores are sealed without bubbles using a top cap with a suspended stirrer. Time courses of 4-7 sample points are used to determine the rate of sediment water exchange. Artificial illumination simulates day-time conditions for shallow photosynthetic sediments, and in conjunction with dark incubations can provide net exchanges on a daily basis. The net measurement of N2 is made possible by sampling a time course of dissolved gas concentrations, with high precision mass spectrometric analysis of N2:Ar ratios providing a means to measure N2 concentrations. We have successfully applied this approach to lakes, reservoirs, estuaries, wetlands and storm water ponds, and with care, this approach provides valuable information on biogeochemical balances in aquatic ecosystems.

从附近的Choptank河（切萨皮克湾，MD）水产养殖设施泥沙通量测量结果如图1所示，这些结果在生态系统中的解释在其他地方提出26。在孵育7小时进行，暗孵育接着照亮孵育数据。从两个芯数据示以及水柱只控制。在氧的迅速下降在黑暗中被光照减弱几分;微藻生产的光合速率并不如呼吸，与照明为氧的变化率下降的主要影响。控制核心经历了氧浓度小幅下降，在光线黑暗和小的增加。 氩比和:在N 2浓度由N 2确定所观察到的温度和盐度27计算的饱和氩文献值。在0.02％的典型精度为N 2:氩比，这些数据是精确至〜0.1微摩尔L -1 的 N 2。沉积物核心和水柱空白芯曾在N 2随时间增加，与增加的核率要高得多。在光照条件下，山坡上大体相似，以N 2变化率暗。 溶解NH 4 +通量相当高的在这个网站上，有&gt; 20微摩尔升暗增加-1一个核心。照亮NH + 4通量要低得多。两个内核和水柱空白降低了NOx的-浓度随着时间的推移，光照时拉平。对于所有的通量，芯体积和其他有关参数对浓度数据和数据示于<st<html>荣&gt;表1和2。 <img alt="图1" src="/files/ftp_upload/54098/54098fig1.jpg" /> 图从Choptank河浅水站点被覆盖有含有培养的牡蛎浮筒1时间过程的数据，这些数据是从复制芯（A和B）和从水柱空白数据被示出。的氧的 N 2浓度，NH 4 +和NO x的- （中NO 3的总和-和NO 2 -呈现为两者的孵化（阴影区域的暗部）和用于培养的照明部分的第四个时间。在黑暗中孵育的点也被照时间序列的第一时间点;灯光在采样的时间导通的行是线性回归和斜坡列于表1中。98 / 54098fig1large.jpg"目标="_空白"&gt;点击此处查看该图的放大版本。 <table fo:keep-together.within-page="1"><tbody><tr><td fo:width="1.8in" style="width:220px"> 氧-黑暗 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 0 </td><td> 235.1 </td><td> 221.7 </td><td> 235.2 </td></tr><tr><td></td><td> 1.3 </td><td> 204.3 </td><td> 170.6 </td><td> 235.3 </td></tr><tr><td></td><td> 2.32 </td><td> 162.7 </td><td> 138.9 </td><td> 232 </td></tr><tr><td></td><td> 3.97 </td><td> 145.3 </td><td> 77.9 </td><td> 222.2 </td></tr><tr><td> R 2 </td><td></td><td> 0.943 </td><td> 0.999 </td><td> 0.836 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> -23.5 </td><td> -35.9 </td><td> -3.4 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> -20.1 </td><td> -32.5 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> -3,095 </td><td> -4,875 </td><td></td></tr><tr><td> 氧-光 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 3.97 </td><td> 145.3 </td><td> 77.9 </td><td> 222.2 </td></tr><tr><td></td><td> 4.88 </td><td> 133.5 </td><td> 68.8 </td><td> 224.3 </td></tr><tr><td></td><td> 5.88 </td><td> 122.8 </td><td> 40.3 </td><td> 221.6 </td></tr><tr><td></td><td> 6.88 </td><td> 116 </td><td> 49.2 </td><td> 230.5 </td></tr><tr><td> R 2 </td><td></td><td> 0.981 </td><td> 0.999 </td><td> 0.994 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> -10.1 </td><td> -9.8 </td><td> 2.9 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> -13 </td><td> -12.7 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> -2,000 </td><td> -1,905 </td><td></td></tr><tr><td> N 2 -黑暗 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 0 </td><td> 466.46 </td><td> 466.40 </td><td> 466.62 </td></tr><tr><td></td><td> 1.3 </td><td> 466.74 </td><td> 467.49 </td><td> 466.11 </td></tr><tr><td></td><td> 2.32 </td><td> 467.55 </td><td> 468.18 </td><td> 466.74 </td></tr><tr><tD&gt; </td><td> 3.97 </td><td> 468.24 </td><td> 468.98 </td><td> 467.12 </td></tr><tr><td> R 2 </td><td></td><td> 0.963 </td><td> 0.98 </td><td> 0.854 </td></tr><tr><td>斜率N 2（微摩尔L -1小时-1） </td><td></td><td> 0.471 </td><td> 0.645 </td><td> 0.12 </td></tr><tr><td>更正斜率N 2（微摩尔L -1小时-1） </td><td></td><td> 0.351 </td><td> 0.525 </td><td></td></tr><tr><td>率N 2 -N（微摩尔米-2小时-1） </td><td></td><td> 108.1 </td><td> 157.5 </td><td></td></tr><tr><td> N 2 -光 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 3.97 </td><td> 468.24 </td><td> 468.98 </td><td> 467.12 </td></tr><tr><td></td><td> 4.88 </td><td> 468.84 </td><td> 469.21 </td><td> 467.26 </td></tr><tr><td></td><td> 5.88 </td><td> 469.39 </td><td> 469.71 </td><td> 467.47 </td></tr><tr><td></td><td> 6.88 </td><td> 469.62 </td><td> 470.04 </td><td> 467.41 </td></tr><tr><td> R 2 </td><td></td><td> 0.96 </td><td> 0.987 </td><td> 0.967 </td></tr><tr><td>斜率N 2（微摩尔L -1小时-1） </td><td></td><td> 0.481 </td><td> 0.378 </td><td> 0.096 </td></tr><tr><td>更正斜率N 2（微摩尔L -1小时-1） </td><td></td><td> 0.386 </td><td> 0.282 </td><td></td></tr><tr><td>率N 2 -N（微摩尔米-2小时-1） </td><td></td><td> 118.9 </td><td> 84.6 </td><td></td></tr><tr><td>芯表面面积（m 2） </td><td></td><td> 0.003165 </td><td> 0.003165 </td><td></td></tR&gt; <tr><td>核心容积（L） </td><td></td><td> 0.4874 </td><td> 0.4747 </td><td></td></tr></tbody></table> 。Ar和N 2: 对O 2 和N 2 从Choptank河，一个subestuary切萨皮克湾牡蛎养殖浮标下方的沉积物 表1.时间过程数据气体浓度是从O 2派生通过膜入口确定氩比质谱。的时间过程的回归，R 2的值是值&gt; 0.9025（P &lt;0.05）显著。斜率通过线性回归确定和校正斜坡减去水柱只有空白的变化率来确定。阳性率分别为净通量出来的泥沙，阴性率表明通量成沉淀物。在N 2通量数据被表示为N 2 -N，使得COMPA里森到NH 4 +和NO x的-通量更容易。本网站有沉积物主要由淤泥和粘土的具有完全有氧水柱的条件。芯的面积为31.65厘米-2和水柱的深度分别为15.4厘米核心A和15.0为核心B.对于N 2的所有浓度和O 2是微摩尔L-1。对于N 2通量的最后速率N 2 -N表示。 <table fo:keep-together.within-page="1"><tbody><tr><td fo:width="1.8in" style="width:220px"> NH 4 + -黑暗 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 0 </td><td> 10.84 </td><td> 14.09 </td><td> 6.91 </td></tr><tr><td></td><td> 1.3 </td><td> 16.19 </td><td> 20.26 </td><td> 5.83 </td></tr><tr><td></td><td> 2.32 </td><td> 17.07 </td><td> 24.93 </td><td> 5.42 </td></tr><tr><td></td><td> 3.97 </td><td> 22.83 </td><td> 35.43 </td><td> 4.67 </td></tr><tr><td> R 2 </td><td></td><td> 0.968 </td><td> 0.993 </td><td> 0.853 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> 2.88 </td><td> 5.36 </td><td> -0.53 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> 3.41 </td><td> 5.89 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> 525 </td><td> 884 </td><td></td></tr><tr><td> NH + 4 -光 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 3.97 </td><td> 22.83 </TD&gt; <td> 35.43 </td><td> 4.67 </td></tr><tr><td></td><td> 4.88 </td><td> 24.05 </td><td> 36.45 </td><td> 4.13 </td></tr><tr><td></td><td> 5.88 </td><td> 25.00 </td><td> 37.60 </td><td> 3.79 </td></tr><tr><td></td><td> 6.88 </td><td> 26.96 </td><td></td><td></td></tr><tr><td> R 2 </td><td></td><td> 0.978 </td><td> 1 </td><td> 0.966 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> 1.37 </td><td> 1.13 </td><td> -0.55 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> 1.92 </td><td> 1.68 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> 296 </td><td> 252 </td><td></td></tr><tr><td> NO X - - ​​黑暗 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 0 </td><td> 4.12 </td><td> 4.01 </td><td> 4.53 </td></tr><tr><td></td><td> 1.3 </td><td> 3.82 </td><td> 3.58 </td><td> 4.43 </td></tr><tr><td></td><td> 2.32 </td><td> 3.70 </td><td> 3.25 </td><td> 4.28 </td></tr><tr><td></td><td> 3.97 </td><td> 3.19 </td><td> 2.64 </td><td> 4.19 </td></tr><tr><td> R 2 </td><td></td><td> 0.976 </td><td> 0.992 </td><td> 0.967 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> -0.229 </td><td> -0.345 </td><td> -0.089 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> -0.14 </td><td> -0.256 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> -21.6 </td><td> -38.4 </td><td></td></tr><tr><td> 的 NO x - -光 </td><td> 时间（hr） </td><td> 核心A </td><td> 核心B </td><td> 控制 </td></tr><tr><td></td><td> 3.97 </td><td> 3.19 </td><td> 2.64 </td><td> 4.19 </td></tr><tr><td></td><td> 4.88 </td><td> 3.06 </td><td> 2.59 </td><td> 4.06 </td></tr><tr><td></td><td> 5.88 </td><td> 3.18 </td><td> 2.41 </td><td> 4.02 </td></tr><tr><td></td><td> 6.88 </td><td> 2.95 </td><td> 2.35 </td><td> 4.2 </td></tr><tr><td> R 2 </td><td></td><td> 0.934 </td><td> 0.909 </td><td> 0.9 </td></tr><tr><td>斜率（微摩尔L -1小时-1） </td><td></td><td> -0.078 </td><td> -0.103 </td><td> 0 </td></tr><tr><td>更正斜率（微摩尔L -1小时-1） </td><td></td><td> -0.078 </td><td> -0.103 </td><td></td></tr><tr><td>速率（微摩尔米-2小时-1） </td><td></td><td> -12 </td><td> -15.5 </td><td></td></tr><tr><td>芯表面面积（m 2） </td><td></td><td> 0.003165 </td><td> 0.003165 </td><td></td></tr><tr><td>核心容积（L） </td><td></td><td> 0.4874 </td><td> 0.4747 </td><td></td></tr></tbody></table> 表2. NH 4 + 和NO x 的 时间过程数据 - 来自用于表1中的时间过程回归的 R 相同沉积物芯 2的值是值&gt; 0.9025（P &lt;0.05）显著。斜率通过线性回归确定和校正斜坡减去水柱只有空白的变化率来确定。阳性率分别为净通量出了泥沙，阴性率表明通量成沉淀物。为NH 4 +和NO 2浓度全部-都是微摩尔L -1。

Watch this Scientific Journal Video about The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations at JoVE.com

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Here, we present small core incubations for the measurement of sediment-water gas and solute exchange. These will provide reliable measurements of sediment-water exchange that assess the role of sediment in influencing biological and biogeochemical processes in aquatic ecosystems.

Ø的底栖交易所<sub&gt; 2</sub&gt;，N<sub&gt; 2</sub&gt;和营养盐使用小的核心孵化

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in ...

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Environment

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

9.5K 次观看.  University of Maryland Center for Environmental Science. Here, we present small core incubations for the measurement of sediment-water gas and solute exchange. These will provide reliable measurements of sediment-water exchange that assess the role of sediment in influencing biological and biogeochemical processes in aquatic ecosystems. 

视频: The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Measuring Fluxes of Mineral Nutrients and Toxicants in Plants with Radioactive Tracers

Unidirectional influx and efflux of nutrients and toxicants, and their resultant net fluxes, are central to the nutrition and toxicology of plants. Radioisotope tracing is a major technique used to measure such fluxes, both within plants, and between plants and their environments. Flux data obtained with radiotracer protocols can help elucidate the capacity, mechanism, regulation, and energetics of transport systems for specific mineral nutrients or toxicants, and can provide insight into compartmentation and turnover rates of subcellular mineral and metabolite pools. Here, we describe two major radioisotope protocols used in plant biology: direct influx (DI) and compartmental analysis by tracer efflux (CATE). We focus on flux measurement of potassium (K+) as a nutrient, and ammonia/ammonium (NH3/NH4+) as a toxicant, in intact seedlings of the model species barley (Hordeum vulgare L.). These protocols can be readily adapted to other experimental systems (e.g., different species, excised plant material, and other nutrients/toxicants). Advantages and limitations of these protocols are discussed.

In planta measurement of nutrient and toxicant fluxes is essential to the study of plant nutrition and toxicity. Here, we cover radiotracer protocols for influx and efflux determination in intact plant roots, using potassium (K+) and ammonia/ammonium (NH3/NH4+) fluxes as examples. Advantages and limitations of such techniques are discussed.

植物与放射性示踪剂测量矿质营养和毒物的通量

Unidirectional influx and efflux of nutrients and toxicants, and their resultant net fluxes, are central to the nutrition and toxicology of plants. ...

科研

环境科学

Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is built and can be transported to a temporary work space close to field sampling site(s) to facilitate rapid analysis. Cores are extruded into a portable glove bag, where they are sectioned and each 1-3 cm thick section (depending on core diameter) is sealed into 50 ml centrifuge tubes. Pore waters are separated with centrifugation outside of the glove bag and then returned to the glove bag for separation from the sediment. These extracted pore water samples can be analyzed immediately. Immediate analyses of redox sensitive species, such as sulfide, iron speciation, and arsenic speciation indicate that oxidation of pore waters is minimal; some samples show approximately 100% of the reduced species, e.g. 100% Fe(II) with no detectable Fe(III). Both sediment and pore water samples can be preserved to maintain chemical species for further analysis upon return to the laboratory.

A protocol for sectioning sediment cores and extracting pore waters under anoxic conditions in order to permit analysis of redox sensitive species in both solids and fluids is presented.

沉积物核心切片和孔隙水萃取缺氧条件下

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is ...

A Protocol for Collecting and Constructing Soil Core Lysimeters

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the landscape has complex and varied soil morphology, an accompanying disparity in flow paths for leachate through the soil macropore and matrix structure is present. The rate of flow through these paths is further affected by antecedent soil moisture. Lysimeters are used to quantify flow rate, volume of water and concentration of nutrients leaching downward through soils. While many lysimeter designs exist, accurately determining the volume of water and mass balance of nutrients is best accomplished with bounded lysimeters that leave the natural soil structure intact. 
Here we present a detailed method for the extraction and construction of soil core lysimeters equipped with soil moisture sensors at 5 cm and 25 cm depths. Lysimeters from four different Coastal Plain soils (Bojac, Evesboro, Quindocqua and Sassafras) were collected on the Delmarva Peninsula and moved to an indoor climate controlled facility. Soils were irrigated once weekly with the equivalent of 2 cm of rainfall to draw down soil nitrate-N concentrations. At the end of the draw down period, poultry litter was applied (162 kg TN ha-1) and leaching was resumed for an additional five weeks. Total recovery of applied irrigation water varied from 71% to 85%. Nitrate-N concentration varied over the course of the study from an average of 27.1 mg L-1 before litter application to 40.3 mg L-1 following litter application. While greatest flux of nutrients was measured in soils dominated by coarse sand (Sassafras) the greatest immediate flux occurred from the finest textured soil with pronounced macropore development (Quindocqua).

A detailed method for extraction and assembly of intact soil core lysimeters and their use for study of leachate and associated loss of nutrients from surface applied poultry litter is demonstrated.

一种用于收集和构建土芯协议测渗计

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the ...

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and detritus, and excreting particulate and dissolved compounds, they serve as important agents for benthic-pelagic coupling. Accurately measuring the compounds removed and excreted by suspension feeders (such as sponges, ascidians, polychaetes, bivalves) is crucial for the study of their physiology, metabolism, and feeding ecology, and is fundamental to determine the ecological relevance of the nutrient fluxes mediated by these organisms. However, the assessment of the rate by which suspension feeders process particulate and dissolved compounds in nature is restricted by the limitations of the currently available methodologies. Our goal was to develop a simple, reliable, and non-intrusive method that would allow clean and controlled water sampling from a specific point, such as the excurrent aperture of benthic suspension feeders, in situ. Our method allows simultaneous sampling of inhaled and exhaled water of the studied organism by using minute tubes installed on a custom-built manipulator device and carefully positioned inside the exhalant orifice of the sampled organism. Piercing a septum on the collecting vessel with a syringe needle attached to the distal end of each tube allows the external pressure to slowly force the sampled water into the vessel through the sampling tube. The slow and controlled sampling rate allows integrating the inherent patchiness in the water while ensuring contamination free sampling. We provide recommendations for the most suitable filtering devices, collection vessel, and storing procedures for the analyses of different particulate and dissolved compounds. The VacuSIP system offers a reliable method for the quantification of undisturbed suspension feeder metabolism in natural conditions that is cheap and easy to learn and apply to assess the physiology and functional role of filter feeders in different ecosystems.

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

VacuSIP，对改进的方法INEX<em&gt;原位</em&gt;颗粒物与测量溶解的化合物加工后主动悬挂给料机

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and ...

A Simple Approach to Manipulate Dissolved Oxygen for Animal Behavior Observations

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal behavior questions. The protocol described here provides a simple, reproducible, and controlled method to manipulate DO to study behavioral response in aquatic organisms resulting from hypoxic and anoxic conditions. While performing degasification of water with nitrogen is commonly used in laboratory settings, no explicit method for ecological (aquatic) application exists in the literature, and this protocol is the first to describe a protocol to degasify water to observe organismal response. This technique and protocol were developed for direct application for aquatic macroinvertebrates; however, small fish, amphibians, and other aquatic vertebrates could be easily substituted. It allows for easy manipulation of DO levels ranging from 2 mg/L to 11 mg/L with stability for up to a 5 min animal-observation period. Beyond a 5 min observation period water temperatures began to rise, and at 10 min DO levels became too unstable to maintain. The protocol is scalable to the study organism, reproducible, and reliable, allowing for rapid implementation into introductory teaching labs and high-level research applications. The expected results of this technique should relate dissolved oxygen changes to behavioral responses of organisms.

This article describes a simple and reproducible protocol to manipulate dissolved oxygen conditions in a laboratory setting for animal behavior studies. This protocol may be used in both teaching and research laboratory settings to evaluate organismal response of macroinvertebrates, fishes, or amphibians to changes in dissolved oxygen concentration.

一个简单的方法来操作的动物行为观察溶解氧

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal ...

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Dissolved organic matter (DOM) is a highly diverse mixture of molecules providing one of the largest sources of energy and nutrients to stream ecosystems. Yet the in situ study of DOM is difficult as the molecular complexity of the DOM pool cannot be easily reproduced for experimental purposes. Nutrient additions to streams however, have been shown to repeatedly alter the in situ and ambient DOM pool. Here we demonstrate an easily replicable field-based method for manipulating the ambient pool of DOM at the ecosystem scale. During nutrient pulse experiments changes in the concentration of both dissolved organic carbon and dissolved organic nitrogen can be examined across a wide-range of nutrient concentrations. This method allows researchers to examine the controls on the DOM pool and make inferences regarding the role and function that certain fractions of the DOM pool play within ecosystems. We advocate the use of this method as a technique to help develop a deeper understanding of DOM biogeochemistry and how it interacts with nutrients. With further development this method may help elucidate the dynamics of DOM in other ecosystems.

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Dissolved organic matter provides an important source of energy and nutrients to stream ecosystems. Here we demonstrate a field-based method to manipulate the ambient pool of dissolved organic matter in situ through easily replicable nutrient pulses.

了解溶解有机物生物地球化学通过<em&gt;原位</em&gt;在河流生态系统营养手法

Dissolved organic matter (DOM) is a highly diverse mixture of molecules providing one of the largest sources of energy and nutrients to stream ecosystems. ...

Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in water resources is a prerequisite for understanding the drivers of the pollutant loads and for making informed water resource management decisions. The commonly used &#34;grab sampling&#34; method provides the concentrations of pollutants at the time of sampling (i.e., a snapshot concentration) and may under- or overpredict the pollutant concentrations and loads. Continuous monitoring of nutrients and sediment has recently received more attention due to advances in computing, sensing technology, and storage devices. This protocol demonstrates the use of sensors, sondes, and instrumentation to continuously monitor in situ nitrate, ammonium, turbidity, pH, conductivity, temperature, and dissolved oxygen (DO) and to calculate the loads from two streams (ditches) in two agricultural watersheds. With the proper calibration, maintenance, and operation of sensors and sondes, good water quality data can be obtained by overcoming challenging conditions such as fouling and debris buildup. The method can also be used in watersheds of various sizes and characterized by agricultural, forested, and/or urban land.

With the advancement of technology and the rise in end-user expectations, the need and use of higher temporal resolution data for pollutant load estimation has increased. This protocol describes a method for continuous in situ water quality monitoring to obtain higher temporal resolution data for informed water resource management decisions.

农业流域营养盐和泥沙的连续河道监测

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in ...

Measuring the Flight Ability of the Ambrosia Beetle, Platypus Quercivorus (Murayama), Using a Low-Cost, Small, and Easily Constructed Flight Mill

The ambrosia beetle, Platypus quercivorus (Murayama), is the vector of a fungal pathogen that causes mass mortality of Fagaceae trees (Japanese oak wilt). Therefore, knowing the dispersal capacity may help inform trapping/tree removal efforts to prevent this disease more effectively. In this study, we measured the flight velocity and duration and estimated the flight distance of the beetle using a newly developed flight mill. The flight mill is low cost, small, and constructed using commonly available items. Both the flight mill arm and its vertical axis comprise a thin needle. A beetle specimen is glued to one tip of the arm using instant glue. The other tip is thick due to being covered with plastic, thus it facilitates the detection of rotations of the arm. The revolution of the arm is detected by a photo sensor mounted on an infrared LED, and is indicated by a change in the output voltage when the arm passed above the LED. The photo sensor is connected to a personal computer and the output voltage data are stored at a sampling rate of 1 kHz. By conducting experiments using this flight mill, we found that P. quercivorus can fly at least 27 km. Because our flight mill comprises cheap and small ordinary items, many flight mills can be prepared and used simultaneously in a small laboratory space. This enables experimenters to obtain a sufficient amount of data within a short period.

Measuring the Flight Ability of the Ambrosia Beetle, Platypus Quercivorus Murayama, Using a Low-Cost, Small, and Easily Constructed Flight Mill

We developed a low cost and small flight mill, constructed with commonly available items and easily used in experimentation. Using this apparatus, we measured the flight ability of an ambrosia beetle, Platypus quercivorus.

利用低成本、小型、易于建造的Quercivorus测量豚草甲虫、鸭嘴兽的飞行能力 (村山富市)

The ambrosia beetle, Platypus quercivorus (Murayama), is the vector of a fungal pathogen that causes mass mortality of Fagaceae trees (Japanese oak wilt). ...

Methods for Image-based Surveys of Benthic Macroinvertebrates and Their Habitat Exemplified by the Drop Camera Survey for the Atlantic Sea Scallop

Underwater imaging has long been used in the field of marine ecology but decreasing costs of high-resolution cameras and data storage have made the approach more practical than in the past. Image-based surveys allow for initial samples to be revisited and are non-invasive compared to traditional survey methods that typically involve nets or dredges. Protocols for image-based surveys can vary greatly but should be driven by target species behavior and survey objectives. To demonstrate this, we describe our most recent methods for an Atlantic sea scallop (Placopecten magellanicus) drop camera survey to provide a procedural example and representative results. The procedure is divided into three critical steps that include survey design, data collection, and data products. The influence of scallop behavior and the survey goal of providing an independent assessment of the U.S. sea scallop resource on the survey procedure are then discussed in the context of generalizing the method. Overall, the broad applicability and flexibility of the University of Massachusetts Dartmouth School for Marine Science and Technology (SMAST) drop camera survey demonstrates the method could be generalized and applied to a variety of sessile invertebrates or habitat focused research.

Image based surveying is an increasingly practical, non-invasive method to sample the marine environment. We present the protocol of a drop camera survey that estimates the abundance and distribution of the Atlantic sea scallop (Placopecten magellanicus). We discuss how this protocol can be generalized for application to other benthic macroinvertebrates.

基于图像的海底无脊椎动物及其栖息地调查方法大西洋扇贝落相机调查

Underwater imaging has long been used in the field of marine ecology but decreasing costs of high-resolution cameras and data storage have made the ...

Detection of Viruses from Bioaerosols Using Anion Exchange Resin

This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid impingement-based air sampling devices for efficacious concentration of negatively-charged viruses from bioaerosols. Thus, the resin serves as an additional concentration step in the bioaerosol sampling workflow. Nucleic acid extraction of the viral particles is then performed directly from the anion exchange resin, with the resulting sample suitable for molecular analyses. Further, this protocol describes a custom-built bioaerosol chamber capable of generating virus-laden bioaerosols under a variety of environmental conditions and allowing for continuous monitoring of environmental variables such as temperature, humidity, wind speed, and aerosol mass concentration. The main advantage of using this protocol is increased sensitivity of viral detection, as assessed via direct comparison to an unmodified conventional liquid impinger. Other advantages include the potential to concentrate diverse negatively-charged viruses, the low cost of anion exchange resin (~$0.14 per sample), and ease of use. Disadvantages include the inability of this protocol to assess infectivity of resin-adsorbed viral particles, and potentially the need for the optimization of the liquid sampling buffer used within the impinger.

An anion exchange resin-based method, adapted to liquid impingement-based bioaerosol sampling of viruses is demonstrated. When coupled with downstream molecular detection, the method allows for facile and sensitive detection of viruses from bioaerosols.