Agradecemos Manel Bolivar por sua ajuda no trabalho de campo. Somos gratos ao &quot;Parc Natural del Montgrí, les Illes Medes i el Baix Ter&quot; por seu apoio às nossas pesquisas e amostragem permissões. O manipulador submarino foi projetado por Ayelet Dadon-Pilosof e fabricado pelo Sr. Pilosof. Este trabalho foi apoiado pelo projecto Governo espanhol CSI-Coral [número de concessão CGL2013-43106-R para RC e MR] e por uma bolsa FPU do &quot;Ministerio de Educación, Cultura y Deporte (MECD)&quot; a TM. Esta é uma contribuição do Biogeoquímica Marinha e grupo Pesquisa em Mudanças Globais financiado pelo Governo Catalão [número de concessão 2014SGR1029] e ISF concessão 1280/13 e BSF concessão 2.012.089 para G. Yahel.

<ol>
	<li>Gili, J. M., Coma, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benthic+suspension+feeders:+their+paramount+role+in+littoral+marine+food+webs.">Benthic suspension feeders: their paramount role in littoral marine food webs.</a> Trends. Ecol. Evol. 13 (8), 316-321 (1998).</li><li>Reiswig, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+pumping+activities+of+tropical+Demospongiae.">In situ pumping activities of tropical Demospongiae.</a> Mar. 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The authors have nothing to disclose.

etapas preparatórias Frascos de colector para os DOM e análise de nutrientes Uma vez que os navios de colector podem interagir com micro-constituintes dissolvidos e as paredes do amostrador pode ser um substrato para as bactérias de crescimento 30-34, diferentes frascos de DOM e recolha de nutrientes foram testados. Borosilicato não é recomendado para a quantificação de sílica 33,35, uma vez...

Alimentadores de suspensão bentônicos desempenham um papel essencial no funcionamento dos ecossistemas marinhos 1. Ao filtrar grandes volumes de água 2,3, eles removem e excretar partículas (plâncton e detritos) e compostos dissolvidos 1 (e referências) e são um importante agente de acoplamento de 4,5 bentônica-pelágica e ciclagem de nutrientes 6,7. Com precisão medir a partículas e compostos dissolvidos removidos e excretados pelos alimentadores de suspensão bentônicas (como esponjas, ascídias, poliquetas, e bivalves) é fundamental para compreender a sua fisiologia, metabolismo e ecologia alimentar. Juntamente com bombeamento medições da taxa, ele também permite a quantificação dos fluxos de nutrientes mediadas por estes organismos e seu impacto ecológico na qualidade da água, bem como em processos de escala do ecossistema. Escolhendo o método adequado para medir as taxas de remoção e produção de partículas e com dissolvidalibras por filtradores de suspensão é fundamental para a obtenção de dados fiáveis ​​sobre a sua atividade alimentar 8. Como apontado por Riisgård e outros, inadequadas metodologias viés resultados, distorcer as condições experimentais, produzir estimativas incorretas de ingestão e excreção de certas substâncias, e pode levar à quantificação errônea dos fluxos de nutrientes processados ​​por esses organismos. Os dois métodos mais utilizados para medir partículas e fluxos de nutrientes dissolvidos em alimentadores do filtro envolver a incubação (técnicas indiretas) ou cobrança simultânea de ambiente e água expirado (técnicas diretas). Incubação técnicas baseiam-se na medição da taxa de alteração da concentração de partículas e nutrientes dissolvidos na água incubadas, e estimar as taxas de produção ou remoção comparação com os controlos adequados 8. No entanto, encerrando um organismo em uma câmara de incubação pode alterar a sua feeding e comportamento de bombagem devido a alterações no regime de fluxo natural, devido a uma diminuição em oxigénio e / ou na concentração de alimentos, ou devido à acumulação de compostos excreção na água de incubação 7,9 (e suas referências). Em adição aos efeitos de confinamento e de abastecimento de água modificado, uma grande tendência de técnicas de incubação decorre de efeitos de re-filtração (ver por exemplo 10). Embora alguns destes problemas metodológicos foram superadas, utilizando o volume direito e forma do recipiente de incubação 11 ou com a introdução de um sistema de redoma de recirculação 12 in situ, esta técnica muitas vezes subestima taxas de remoção e de produção. A quantificação do metabolismo de compostos dissolvidos tais como o azoto orgânico dissolvido (DON) e o carbono (DOC) ou nutrientes inorgânicos, tem provado ser especialmente propensos a erros causados ​​por técnicas de incubação 13. No final dos anos 60 e início dos anos 70, Henry Reiswig9,14,15 foi pioneira na aplicação de técnicas diretas para quantificar remoção de partículas por esponjas Caribe gigantes, por amostragem separadamente a água inspirado e expirado pelos organismos in situ. Devido à dificuldade de aplicar a técnica de Reiswig em alimentadores de suspensão menores e em condições submarinas mais desafiadoras, a maior parte da investigação neste campo foi restrito ao laboratório (in vitro) empregando principalmente técnicas de incubação indiretos 16. Yahel e colegas reaparelhado Reiswig do direta técnica in situ a trabalhar em condições de menor escala. Seu método, denominado Inex 16, é baseado em amostragem subaquática simultânea da água inalado (In) e expirado (Ex) por organismos não perturbadas. A concentração diferente de uma substância (por exemplo, bactérias) entre um par de amostras (iNEX) proporciona uma medida da retenção (ou produção) de substância que pelo animal. A técnica Inex emprega tubos abertas ebaseia-se no jacto excurrente produzido pela actividade de bombeamento do organismo estudado para substituir passivamente a água ambiente no tubo de recolha. Enquanto Yahel e colegas aplicaram com sucesso esta técnica no estudo de mais de 15 suspensão alimentadores diferentes taxa (por exemplo, 17), o método é limitado pelo alto nível de prática e experiência necessários, pelo tamanho minúsculo de alguns orifícios excurrentes, e por condições do mar. Para superar esses obstáculos, desenvolvemos uma técnica alternativa baseada na sucção controlada da água amostrada através de tubos hora (diâmetro externo &lt;1,6 mm). Nosso objetivo era criar um dispositivo simples, confiável e de baixo custo que permitiria limpo e controlado de amostragem de água situ a partir de um ponto muito específico, como o orifício excurrent de alimentadores de suspensão bentônicos. Para ser eficaz, o método tem de ser não-intrusivo, de modo a não afectar o regime de fluxo ambiente ou modificar o behavior dos organismos estudados. O dispositivo apresentado aqui é denominado VacuSIP. É uma simplificação do sistema desenvolvido pelo SIP Yahel et ai. (2007) 18 para amostragem por pontos baseado em ROV no fundo do mar. O VacuSIP é consideravelmente mais barato do que a SIP original e foi adaptado para o trabalho baseado em mergulho. O sistema foi projetado de acordo com os princípios apresentados e testados por Wright e Stephens (1978) 19 e Møhlenberg e Riisgård (1978) 20 para ambientes de laboratório. Embora o sistema VacuSIP foi concebido para estudos in situ do metabolismo dos alimentadores de suspensão bentônicos, ele também pode ser usado para os estudos de laboratório e onde é necessária, uma amostra de água de ponto fonte controlada e limpo. O sistema é especialmente útil quando a integração ao longo de períodos prolongados (mínimo de-horas) ou em filtrações in situ são obrigatórios. O VacuSIP tem sido utilizado com sucesso no laboratório Yahel desde 2011, e tem tambémsido empregado em dois estudos recentes de fluxos de nutrientes mediadas por espécies de esponjas das Caraíbas e Mediterrâneo 21 (Morganti et al. apresentado). O uso de samplers específicas, a duração de amostragem prolongada, e as condições de campo, em que VacuSIP é aplicado, implicará alguns desvios protocolos oceanográficos padrão para coletar, filtrar, analisar e armazenar amostras de analitos sensíveis. Para reduzir o risco de contaminação pelo sistema VacuSIP ou o risco de modificação da água amostrada por actividade bacteriana após a recolha, foi testada em vários procedimentos de filtração e de armazenamento in situ. Diferentes dispositivos de filtragem, recipientes de recolha, armazenamento e procedimentos foram examinados a fim de alcançar a técnica mais adequada para a análise de dissolvido inorgânico (PO 4 3-, NO x -, NH 4 +, SiO 4) e orgânico (DOC + DON) compostos e ultra-plâncton (&lt;1081; m) e partículas orgânicas (POC + PON amostragem). Para reduzir ainda mais o risco de contaminação, especialmente em condições de campo, o número de passos de manipulação foi reduzida ao mínimo. O formato visual no qual o método é apresentado é orientada para facilitar a reprodutibilidade e a reduzir o tempo necessário para aplicar a técnica de forma eficiente. Visão geral do sistema Para obter a amostra em água in situ bombeada de alimentadores de suspensão com orifícios exhalant tão pequenas quanto 2 mm, a actividade de bombagem de cada espécime é primeiramente visualizada através da libertação filtrada fluoresceína tingido água do mar junto ao orifício de inalação (s) e observando-se o seu fluxo a partir da abertura excurrente 16 (ver também a Figura 2B em 18). A água inspirado e expirado pelo espécimen do estudo (incurrent e excurrentes) são então amostrados simultaneamente com a utilização de um par de tubos instalados na hora manipulador-construído sob encomenda ou em dois dos &quot;ARMS &quot;de um tripé portátil flexível de cabeça para baixo (Figura 1 e suplementares Vídeo 1). A água inalado pelo organismo estudo é recolhido por posicionando cuidadosamente a extremidade proximal de um tubo no interior ou perto da abertura de inalação do organismo estudo. Um idêntico tubo é então posicionado no interior do orifício excurrente. Esta operação requer o cuidado de evitar o contacto ou perturbação do animal, por exemplo, por ressuspensão do sedimento. para iniciar a amostragem, um mergulhador perfura um septo no recipiente de recolha com uma agulha de seringa ligado à extremidade distal de cada tubo, permitindo que a pressão de água externa para forçar a água amostrada para dentro do recipiente através do tubo de amostragem. a sucção é iniciada pelo vácuo criado previamente nos frascos e pela diferença de pressão entre a água externa e o recipiente da amostra evacuada . Para garantir uma coleção de água limpa exalado e evitar aspiração acidental de ambiágua ent 16, a taxa de amostragem da água deve ser mantida a uma taxa significativamente mais baixa (&lt;10%) do que a taxa de fluxo excurrent. A taxa de sucção é controlada pelo comprimento do tubo e o seu diâmetro interno (ID). O diâmetro interno pequeno também garante um volume morto insignificante (&lt;200 ul por metro de tubo). Recolha de amostras durante períodos prolongados (minutos a horas) faz com que seja possível integrar o patchiness inerente da maioria das substâncias de interesse. Para garantir que as amostras sejam adequadamente preservadas em sessões de amostragem subaquáticas prolongadas, bem como para o transporte para o laboratório, uma filtração em situ é recomendado para analitos sensíveis. A seleção dos vasos de amostragem, montagem de filtração, e tubos são ditadas pelos organismos de estudo e a questão de pesquisa específica. O protocolo descrito abaixo assume que um perfil metabólico completo é de interesse (para um resumo ver Figura 2). No entanto, a natureza modular do protocolo permite Fou modificação fácil para acomodar esquemas de amostragem simples ou até mesmo muito diferentes. Para um perfil metabólico completo, o protocolo de amostragem deve incluir os seguintes passos: (1) A visualização de fluxo; (2) alimentação amostragem ultra-plâncton (plâncton &lt;10 mm); (3) A amostragem absorção de nutrientes inorgânicos e excreção (usando filtros em linha); (4) Amostra dissolvida absorção orgânica e excreção (usando filtros em linha); (5) a alimentação de partículas e excreção (usando filtros em linha); (6) Repita o passo 2 (alimentação ultra-plâncton como verificação de qualidade); (7) O fluxo de visualização. Quando logisticamente viável, recomenda-se que as medições de perfil metabólicas são combinados com a taxa de bombeamento (por exemplo, o método a velocidade da frente de corante, em 16), bem como com as medições de respiração. Estas medições são as melhores tomadas no início e no final da sessão de amostragem. Para a medição da respiração, optodes subaquáticas ou micro-eletrodos são preferíveis.

<table><tbody><tr><td>GorillaPod, Original</td><td>Joby</td><td>GP000001</td><td>flexible portable tripod&amp;nbsp;</td></tr><tr><td>Flangeless Ferrule</td><td>IDEX Health &amp;amp; Science&amp;nbsp;</td><td>P-200X</td><td>1/16&quot; in Blue/pk</td></tr><tr><td>Male Nut</td><td>IDEX Health &amp;amp; Science</td><td>P-205X&amp;nbsp;</td><td>1/16&quot; in Green/10&amp;nbsp;pk</td></tr><tr><td>Female to Female Luer</td><td>IDEX Health &amp;amp; Science&amp;nbsp;</td><td>P-658</td><td></td></tr><tr><td>Female-Male Luer</td><td>IDEX Health &amp;amp; Science&amp;nbsp;</td><td>P-655</td><td></td></tr><tr><td>Peek Tubing (254&amp;nbsp;&amp;micro;m ID)</td><td>IDEX Health &amp;amp; Science&amp;nbsp;</td><td>1531</td><td>1/16&quot; OD x 0.01&amp;nbsp;in ID x 5&amp;nbsp;ft length. Alternative ID can be used.</td></tr><tr><td>Two component resin epoxy</td><td>IVEGOR</td><td>9257</td><td>Mix well the two component resin before use</td></tr><tr><td>(TOC) EPA Vials</td><td>Cole -Parmer</td><td>03756-20</td><td>40 ml glass vials. Manufactured also by Thomas Scientific (ref. number 9711F09).</td></tr><tr><td>HDPE Vials</td><td>Wheaton</td><td>986701 (E78620)</td><td>20 ml high-density polyethylene vials</td></tr><tr><td>Vacuette Z no additive</td><td>Greiner bio-one</td><td>455001</td><td>pre-vacuum by the manufacturer&amp;nbsp;</td></tr><tr><td>Septum Sample Bottles</td><td>Thomas Scientific</td><td>1755C01</td><td>250 ml glass bottles&amp;nbsp;</td></tr><tr><td>Septum Cap 1</td><td>Wheaton</td><td>W240844SP (E7865R)</td><td>22-400 for HDPE vials&amp;nbsp;</td></tr><tr><td>Septum Cap 2</td><td>Wheaton</td><td>W240846 (1078-5553)</td><td>24-400 for glass vials and bottles. Also manufactured by Thermo Scientific National (ref. 03-377-42).</td></tr><tr><td>In-line stainless steel Swinney Filter holders</td><td>Pall</td><td>516-9067</td><td>13 mm of diameter</td></tr><tr><td>PTFE Seal Washer</td><td>Pall&amp;nbsp;</td><td>516-8064</td><td>ring for stainless steel filter holders</td></tr><tr><td>TCLP Glass Filters</td><td>Pall&amp;nbsp;</td><td>516-9126</td><td>binder-free glass fiber filters, 13&amp;nbsp;mm of diameter, pore size 0.7&amp;nbsp;&amp;micro;m</td></tr><tr><td>Polycarbonate Filter Holders</td><td>Cole -Parmer</td><td>17295</td><td>13 mm of diameter</td></tr><tr><td>Isopore Membrane Filters</td><td>Millipore</td><td>GTTP01300</td><td>13&amp;nbsp;mm of diameter, pore size 0.2&amp;nbsp;&amp;micro;m</td></tr><tr><td>Contrad 70 Solution&amp;nbsp;</td><td>Decon Labs</td><td>1002</td><td>highly soluble basic mix of anionic and non-ionic surfactant solution&amp;nbsp;</td></tr><tr><td>Sterile Syringe Filters</td><td>VWR International Eurolab S.L.</td><td>514-0061P</td><td>25&amp;nbsp;mm of diameter , pore size 0.2&amp;nbsp;&amp;micro;m</td></tr><tr><td>Fluorescein</td><td>Sigma-Aldrich</td><td>(old ref.28802) 46955-100G</td><td>100&amp;nbsp;g</td></tr><tr><td>Holdex, disposable,sterile</td><td>Greiner bio-one</td><td>450263</td><td>sterile, single-use tube holder with off-center luer for Vacuette</td></tr><tr><td>Sterile Needles</td><td>IcoGammaPlus</td><td>5160</td><td>0.7&amp;nbsp;mm x 30&amp;nbsp;mm</td></tr><tr><td>Cryovials Nalgene</td><td>Nalgene</td><td>V5007(Cat. No.5000-0020)</td><td>2&amp;nbsp;ml</td></tr><tr><td>Cryobox carton&amp;nbsp;</td><td>Rubilabor</td><td>M-600</td><td>145x145x55&amp;nbsp;mm p/microtube 1.5&amp;nbsp;ml</td></tr><tr><td>Orthophosphoric Acid</td><td>Sigma</td><td>79617 or Alternatively use Ultra-Pure Hydrochloric acid, final concertation 0.1%</td><td></td></tr><tr><td>Paraformaldehyde</td><td>Sigma</td><td>P6148</td><td>500&amp;nbsp;g</td></tr><tr><td>Glutaraldehyde</td><td>Merck</td><td>8,206,031,000</td><td>25%, 1 L</td></tr><tr><td>Hand Vacuum Pump&amp;nbsp;</td><td>B&amp;uuml;rkle&amp;nbsp;</td><td>5620-2181 or Alternatively use standard laboratory vacuum pump</td><td></td></tr></tbody></table>

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.

Otimização dos métodos de coleta de água do mar Seleção de frascos de coletor e procedimento de limpeza vasos de coleta VacuSIP compatíveis devem ter um septo que permite amostragem a ser iniciada por perfuração com uma agulha de seringa. Eles devem suportar a pressão debaixo d&#39;água elevada (2-3 bares no scub...

Watch this Scientific Journal Video about VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders at JoVE.com

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, um método melhorado para Inex<em&gt; In Situ</em&gt; Medição de partículas e dissolvidos compostos Processado por alimentadores de suspensão ativa

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

vacusip-an-improved-inex-method-for-situ-measurement-particulate

Research

JoVE Journal

Environment

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

10.8K visualizações.  Centre d’Estudis Avançats de Blanes (CEAB-CSIC). 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.

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

Quantitatively Measuring In situ Flows using a Self-Contained Underwater Velocimetry Apparatus (SCUVA)

The ability to directly measure velocity fields in a fluid environment is necessary to provide empirical data for studies in fields as diverse as oceanography, ecology, biology, and fluid mechanics. Field measurements introduce practical challenges such as environmental conditions, animal availability, and the need for field-compatible measurement techniques. To avoid these challenges, scientists typically use controlled laboratory environments to study animal-fluid interactions. However, it is reasonable to question whether one can extrapolate natural behavior (i.e., that which occurs in the field) from laboratory measurements. Therefore, in situ quantitative flow measurements are needed to accurately describe animal swimming in their natural environment.
We designed a self-contained, portable device that operates independent of any connection to the surface, and can provide quantitative measurements of the flow field surrounding an animal. This apparatus, a self-contained underwater velocimetry apparatus (SCUVA), can be operated by a single scuba diver in depths up to 40 m. Due to the added complexity inherent of field conditions, additional considerations and preparation are required when compared to laboratory measurements. These considerations include, but are not limited to, operator motion, predicting position of swimming targets, available natural suspended particulate, and orientation of SCUVA relative to the flow of interest. The following protocol is intended to address these common field challenges and to maximize measurement success.

Quantitatively Measuring In situ Flows using a Self-Contained Underwater Velocimetry Apparatus SCUVA

This protocol provides instructions on how to use a self-contained underwater velocimetry apparatus (SCUVA), which is designed for quantification of in situ animal-generated flows. In addition, this protocol addresses challenges posed by field conditions, and includes operator motion, predicting position of animals, and orientation of SCUVA.

Medir quantitativamente In situ Fluxos usando um Aparelho Autônomo de Velocimetria Underwater (SCUVA)

The ability to directly measure velocity fields in a fluid environment is necessary to provide empirical data for studies in fields as diverse as ...

Bioengenharia

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination control. Developments of some techniques aiming to reduce trace metal contamination in the last couple of decades have resulted in concentrations reported now being orders of magnitude lower than those in the past. These low concentrations often necessitate preconcentration of water samples prior to instrumental analysis of samples. Since contamination can appear in all phases of trace metal analyses, including sample collection (and during preparation of sampling containers), storage and handling, pretreatments, and instrumental analysis, specific care needs to be taken in order to reduce contamination levels at all steps. The effort to develop and utilize "clean techniques" in trace metal studies allows scientists to investigate trace metal distributions and chemical and biological behavior in greater details. This advancement also provides the required accuracy and precision of trace metal data allowing for environmental conditions to be related to trace metal concentrations in aquatic environments.
This protocol that is presented here details needed materials for sample preparation, sample collection, sample pretreatment including preconcentration, and instrumental analysis. By reducing contamination throughout all phases mentioned above for trace metal analysis, much lower detection limits and thus accuracy can be achieved. The effectiveness of "clean techniques" is further demonstrated using low field blanks and good recoveries for standard reference material. The data quality that can be obtained thus enables the assessment of trace metal distributions and their relationships to environmental parameters.

Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

Limpo Amostragem e Análise do Rio e Estuarina Waters de Estudos de metal de rastreamento

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination ...

Ambiente

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.

Monitoramento Contínuo de Nutrientes e Sedimentos em Bacias Agrícolas

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

Capturing Flow-weighted Water and Suspended Particulates from Agricultural Canals During Drainage Events

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.

Nutrients present in particulate form can contribute significantly to the overall loads in agricultural drainage waters. This study describes a novel method to capture flow-weighted water and suspended particulates from farm canal drainage over the entire duration of the drainage event.

Capturando o fluxo ponderado água e partículas em suspensa de canais agrícolas durante eventos de drenagem

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage ...

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

Understanding the ecosystem services and processes provided by vernal ponds and the impacts of anthropogenic activities on their ability to provide these services requires intensive hydrologic monitoring. This sampling protocol using in-situ monitoring equipment was developed to understand the impact of anthropogenic activities on water levels and quality.

Contínua hidrológicos e monitoramento da qualidade do Vernal lagoas de água

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. ...

An Ultra-clean Multilayer Apparatus for Collecting Size Fractionated Marine Plankton and Suspended Particles

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those of suspended/sinking particles. Here, we present an all plastic (Polypropylene and Polycarbonate), multi-layer filtration system for collection of suspended particulate matter (SPM) at sea. This ultra-clean sampling device has been designed and developed specifically for trace element studies. Meticulous selection of all non-metallic materials and utilization of an in-line flow-through procedure minimizes any possible metal contamination during sampling. This system has been successfully tested and tweaked for determining trace metals (e.g., Fe, Al, Mn, Cd, Cu, Ni) on particles of varying size in coastal and open ocean waters. Results from the South China Sea at the South East Asia Time-Series (SEATS) station indicate that diurnal variations and spatial distribution of plankton in the euphotic zone can be easily resolved and recognized. Chemical analysis of size-fractionated particles in surface waters of the Taiwan Strait suggests that the larger particles (&#62;153 &#181;m) were mostly biologically derived, while the smaller particles (10 - 63 &#181;m) were mostly composed of inorganic matter. Apart from Cd, the concentrations of metals (Fe, Al, Mn, Cu, Ni) decreased with increasing size.

Plankton and suspended particles play a major role in the biogeochemical cycles in the ocean. Here, we provide an ultra-clean, low stress method for the collection of various sizes of particles and plankton at sea with the capability of handling large volumes of seawater.

Um aparelho ultra limpo Multicamado para coleta de plâncton marinho tamanho fracionado e partículas em suspensão

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those ...

Design and Use of an Apparatus for Quantifying Bivalve Suspension Feeding at Sea

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves (i.e., mussels, oysters, and clams) presents new challenges. Quantitative data on the feeding behavior of suspension-feeding mollusks is necessary to determine important ecosystem interactions of offshore shellfish farms, including their carrying capacity, the competition with the zooplankton community, the availability of trophic resources at different depths, and the deposition to the benthos. The biodeposition method is used to quantify feeding variables in suspension-feeding bivalves in a natural setting and represents a more realistic proxy than laboratory experiments. This method, however, relies upon a stable platform to satisfy the requirements that water flow rates supplied to the shellfish remain constant and the bivalves are undisturbed. A flow-through device and process for using the biodeposition method to quantify the feeding of bivalve mollusks were modified from a land-based format for shipboard use by building a two-dimensional gimbal table around the device. Planimeter data reveal a minimal pitch and yaw of the chambers containing the test shellfish despite boat motion, the flow rates within the chambers remain constant, and operators are able to collect the biodeposits (feces and pseudofeces) with sufficient consistency to obtain accurate measurements of the bivalve clearance, filtration, selection, ingestion, rejection, and absorption at offshore shellfish aquaculture sites.

A flow-through device for using the biodeposition method to quantify filtration and feeding behavior of bivalve mollusks was modified for shipboard use. A two-dimensional gimbal table built around the device isolates the apparatus from boat motion, thereby allowing the accurate quantification of bivalve filtration variables at offshore shellfish aquaculture sites.

Concepção e utilização de aparelhagem para quantificar a suspensão bivalves alimentação no mar

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves ...

In Situ Chemotaxis Assay to Examine Microbial Behavior in Aquatic Ecosystems

Microbial behaviors, such as motility and chemotaxis (the ability of a cell to alter its movement in response to a chemical gradient), are widespread across the bacterial and archaeal domains. Chemotaxis can result in substantial resource acquisition advantages in heterogeneous environments. It also plays a crucial role in symbiotic interactions, disease, and global processes, such as biogeochemical cycling. However, current techniques restrict chemotaxis research to the laboratory and are not easily applicable in the field. Presented here is a step-by-step protocol for the deployment of the in situ chemotaxis assay (ISCA), a device that enables robust interrogation of microbial chemotaxis directly in the natural environment. The ISCA is a microfluidic device consisting of a 20 well array, in which chemicals of interest can be loaded. Once deployed in aqueous environments, chemicals diffuse out of the wells, creating concentration gradients that microbes sense and respond to by swimming into the wells via chemotaxis. The well contents can then be sampled and used to (1) quantify strength of the chemotactic responses to specific compounds through flow cytometry, (2) isolate and culture responsive microorganisms, and (3) characterize the identity and genomic potential of the responding populations through molecular techniques. The ISCA is a flexible platform that can be deployed in any system with an aqueous phase, including marine, freshwater, and soil environments.

Presented here is the protocol for an in situ chemotaxis assay, a recently developed microfluidic device that enables studies of microbial behavior directly in the environment.

In Situ Chemotaxis Assay para examinar o comportamento microbiano em ecossistemas aquáticos

Microbial behaviors, such as motility and chemotaxis (the ability of a cell to alter its movement in response to a chemical gradient), are widespread ...

Microparticle Manipulation by Standing Surface Acoustic Waves with Dual-frequency Excitations

We demonstrate a method for increasing the tuning ability of a standing surface acoustic wave (SSAW) for microparticles manipulation in a lab-on-a-chip (LOC) system. The simultaneous excitation of the fundamental frequency and its third harmonic, which is termed as dual-frequency excitation, to a pair of interdigital transducers (IDTs) could generate a new type of standing acoustic waves in a microfluidic channel. Varying the power and the phase in the dual-frequency excitation signals results in a reconfigurable field of the acoustic radiation force applied to the microparticles across the microchannel (e.g., the number and location of the pressure nodes and the microparticle concentrations at the corresponding pressure nodes). This article demonstrates that the motion time of the microparticle to only one pressure node can be reduced ~2-fold at the power ratio of the fundamental frequency greater than ~90%. In contrast, there are three pressure nodes in the microchannel if less than this threshold. Furthermore, adjusting the initial phase between the fundamental frequency and the third harmonic results in different motion rates of the three SSAW pressure nodes, as well as in the percentage of microparticles at each pressure node in the microchannel. There is a good agreement between the experimental observation and the numerical predictions. This novel excitation method can easily and non-invasively integrate into the LOC system, with a wide tenability and only a few changes to the experimental set-up.

A protocol for manipulating the microparticles in a microfluidic channel with a dual-frequency excitation is presented.

Manipulação de micropartículas de ondas acústicas de superfície com dupla frequência excitações de pé

We demonstrate a method for increasing the tuning ability of a standing surface acoustic wave (SSAW) for microparticles manipulation in a lab-on-a-chip ...

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Dissolved Solute Sampling Across an Oxic-Anoxic Soil-Water Interface Using Microdialysis Profilers

Biogeochemical processes shift rapidly in both spatial (millimeter scale) and temporal (hour scale to day scale) dimensions at the oxic-anoxic interface in response to disturbances. Deciphering the rapid biogeochemical changes requires in situ, minimally invasive tools with high spatial and temporal sampling resolution. However, the available passive sampling devices are not very useful in many cases either due to their disposable nature or the complexity and extensive workload for sample preparation.
To address this problem, a microdialysis profiler with 33 individual polyethersulfone nanomembrane tubes (semipermeable, &#60;20 nm pore size) integrated into the one-dimensional skeleton (60 mm) was established to iteratively sample the dissolved compounds in porewater across the soil-water interface at a high resolution of 1.8 mm (outer diameter plus one spacing, i.e., 0.1 mm between probes). The sampling mechanism is based on the principle of concentration gradient diffusion. The automatic loading of degassed water allows minimal disturbance to the chemical species across the oxic-anoxic interface.
This paper describes the procedures of device setup and continuous porewater sampling across the soil-water interface on a daily basis. Concentration-depth profiles were selectively measured before (on Day 6) and after (on Day 7) disturbances induced by irrigation. The results showed that concentration-depth profiles were undergoing rapid changes, especially for redox-sensitive elements (i.e., iron and arsenic). These protocols can help investigate the biogeochemical responses across the soil-water interface under various disturbances caused by physical, chemical, and biological factors. The paper thoroughly discusses the advantages and disadvantages of this method for potential use in the environmental sciences.

A microdialysis profiler is described to sample dissolved porewater solutes across an oxic-anoxic soil-water interface in situ with minimal disturbance. This device is designed to capture rapid changes in concentration-depth profiles induced by disturbances at the soil-water interface and beyond.

Amostragem de soluto dissolvido em uma interface água-solo óxico-anóxica usando perfiladores de microdiálise

Biogeochemical processes shift rapidly in both spatial (millimeter scale) and temporal (hour scale to day scale) dimensions at the oxic-anoxic interface ...

VacuSIP, um método melhorado para Inex

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