Name: continuous hydrologic and water quality monitoring of vernal ponds
Uploaded: 2017-11-13T15:00:00
Description: Watch this Scientific Journal Video about Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds at JoVE.com

The authors would like to thank the Pennsylvania State University Office of Physical Plant (OPP) for funding to support this research. Additionally, we would like to thank Drs. Elizabeth W. Boyer, David A. Miller, and Tracy Langkilde at The Pennsylvania State University for their collaborative support of this project.

1. Conducting a Survey of a Vernal Pond Morphology
<ol>
	<li>Select a location to designate as the benchmark and mark it with a small survey or marking flag. 
	NOTE: The location should be a higher elevation than the pond and have line-of-sight from all locations across the pond.</li>
	<li>Assign the benchmark a reference elevation; the exact number does not matter, it simply provides a reference to which all other elevations can be compared.</li>
	<li>Using a tape measure and marking flags, make transects at a 3 ...

<ol>
	<li>Korfel, C. A., Mitsch, W. J., Hetherington, T. E., Mack, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrology+physiochemistry,+and+amphibians+in+natural+and+created+vernal+pool+wetlands.">Hydrology physiochemistry, and amphibians in natural and created vernal pool wetlands.</a> Restor. Ecol. 18 (6), 843-854 (2010).</li><li>Colburn, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Vernal Pools: Natural History and Conservation. , (2004).</li><li>Collins, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amphibian+decline+and+extinction:+What+we+know+and+what+we+need+to+learn.">Amphibian decline and extinction: What we know and what we need to learn.</a> Dis Aquat Org. 92, 93-99 (2013).</li><li>Wake, D. B., Vredenburg, V. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Are+we+in+the+midst+of+the+sixth+mass+extinction?+A+view+from+the+world+of+amphibians.">Are we in the midst of the sixth mass extinction? A view from the world of amphibians.</a> Proc Nat Acad Sci USA. 105, 11466-11473 (2008).</li><li>IUCN. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Conservation International and Nature Conservancy. , (2004).</li><li>Smits, A. P., Skelly, D. K., Bolden, 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=Amphibian+intersex+in+suburban+landscapes.">Amphibian intersex in suburban landscapes.</a> Ecosphere. 5 (1), 11 (2014).</li><li>Brooks, R. T., Miller, S. D., Newsted, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+urbanization+on+water+and+sediment+chemistry+of+ephemeral+forest+pools.">The impact of urbanization on water and sediment chemistry of ephemeral forest pools.</a> J. Freshwater Ecol. 17 (3), (2002).</li><li>Czajka, C. P., Londry, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anaerobic+transformation+of+estrogens.">Anaerobic transformation of estrogens.</a> Environ. Sci. Technol. 367, 932-941 (2006).</li><li>Dytczak, M. A., Londry, K. L., Oleszkiewicz, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biotransformation+of+estrogens+in+nitrifying+activated+sludge+under+aerobic+and+alternating+anoxic/aerobic+conditions.">Biotransformation of estrogens in nitrifying activated sludge under aerobic and alternating anoxic/aerobic conditions.</a> Water Environ. Res. 80 (1), 47-52 (2008).</li><li>Field, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Landscape Surveying. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solar+Angle+Calculator.">Solar Angle Calculator.</a> Solar Electricity Handbook. , (2017).</li><li>Brooks, R. T., Hayashi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Depth-area-volume+and+hydroperiod+relationships+of+ephemeral+(vernal)+forest+pools+in+southern+New+England.">Depth-area-volume and hydroperiod relationships of ephemeral (vernal) forest pools in southern New England.</a> Wetlands. 22 (2), 247-255 (2002).</li><li>Laposata, M. M., Dunson, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+spray-irrigated+wastewater+effluent+on+temporary+pond-breeding+amphibians.">Effects of spray-irrigated wastewater effluent on temporary pond-breeding amphibians.</a> Ecotox. Environ. Safe. 46 (2), 192-201 (2000).</li><li>Qian, Y. L., Mecham, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+effects+of+recycled+wastewater+irrigation+on+soil+chemical+properties+on+golf+course+fairways.">Long-term effects of recycled wastewater irrigation on soil chemical properties on golf course fairways.</a> Agron. J. 97 (3), 717-721 (2005).</li><li>Karraker, N. E., Gibbs, J. P., Vonesh, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impacts+of+road+deicing+salt+on+the+demography+of+vernal+pool-breeding+amphibians.">Impacts of road deicing salt on the demography of vernal pool-breeding amphibians.</a> Ecol. Appl. 18 (3), (2008).</li><li>Gall, H. E., Jafvert, C. T., Jenkinson, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrating+hydrograph+modeling+with+real-time+monitoring+to+generate+hydrograph-specific+sampling+schemes.">Integrating hydrograph modeling with real-time monitoring to generate hydrograph-specific sampling schemes.</a> J. Hydrol. 393, 331-340 (2010).</li><li>Gall, H. E., Sassman, S. A., Lee, L. S., Jafvert, C. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hormone+discharges+from+a+Midwest+tile-drained+agroecosystem+receiving+animal+wastes.">Hormone discharges from a Midwest tile-drained agroecosystem receiving animal wastes.</a> Environ. Sci. Technol. 45, 8755-8764 (2011).</li><li>Pittman, S. E., Jendrek, A. L., Price, S. J., Dorcas, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Habitat+selection+and+site+fidelity+of+Cope's+Gray+Treefrog+(Hyla+chrysoscelis)+at+the+aquatic-terrestrial+ecotone.">Habitat selection and site fidelity of Cope's Gray Treefrog (Hyla chrysoscelis) at the aquatic-terrestrial ecotone.</a> J. Hepatol. 42 (2), 378-385 (2008).</li><li>Vandewege, M. W., Swannack, T. M., Greuter, K. L., Brown, D. J., Forstner, M. R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breeding+site+fidelity+and+terrestrial+movement+of+an+endangered+amphibian,+the+Houston+Toad+(Bufo+Houstonensis).">Breeding site fidelity and terrestrial movement of an endangered amphibian, the Houston Toad (Bufo Houstonensis).</a> Herpet. Conserv. Bio. 8 (2), 435-446 (2013).</li><li>Homan, R. N., Atwood, M. A., Dunkle, A. J., Karr, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Movement+orientation+by+adult+and+juvenile+wood+frogs+(Rana+Sylvatica)+and+american+toads+(Bufo+Americanus)+over+Multiple+Years.">Movement orientation by adult and juvenile wood frogs (Rana Sylvatica) and american toads (Bufo Americanus) over Multiple Years.</a> Herpet. Conserv. Bio. 5 (1), 64-72 (2010).</li></ol>

Significance with Respect to Existing Methods
While monitoring of streams has well-established methodologies developed by the United States Geological Survey (USGS), no such widespread monitoring program exists for understanding vernal pond dynamics. This protocol seeks to provide guidance for how to begin to approach hydrologic and water quality monitoring research at a vernal pond site, with the goal of understanding how physical and chemical factors may be changing over tim...

Vernal ponds are temporary, shallow wetlands that typically contain water from fall to spring and are often dry during the summer months. The inundation period of vernal ponds, generally referred to as the hydroperiod, is primarily controlled by precipitation and evapotranspiration1. 
Vernal ponds can also be referred to as vernal pools, ephemeral ponds, temporary ponds, seasonal ponds, and geographically isolated wetlands2. In the northeastern United States, vernal ponds are most often characterized by the critical habitat they provide for amphibians, serving as the breeding grounds and providing support during early life stages (i.e., tadpoles) and metamorphosis. In California, vernal ponds are characterized by the unique vegetation and endangered plant species that they support2. 
These habitats are increasingly threatened due to land use and climate change, and amphibian populations are experiencing a significant global decline largely due to anthropogenic activities3,4. Water quality concerns due to pollution are also thought to be contributing factors in recent amphibian declines globally5. Furthermore, recent studies have revealed an increased occurrence of intersex characteristics in frogs inhabiting vernal ponds impacted by human wastewater6. There is therefore a need to conduct more intensive monitoring of both natural and impacted vernal ponds to better understand the contributors to the global amphibian decline.
The physical parameters of vernal ponds that need to be measured and monitored include the pond morphology and water level. The morphology is the geometry of the pond, and is developed by conducting a survey to determine changes in elevation across the pond. The survey data are then used to establish a stage-storage curve, which enables the volume of the pond to be estimated based on water level measurements. Because the water level in a vernal pond is heavily influenced by precipitation, measurements should be made at a high temporal resolution to best understand both short (i.e., on the order of minutes to hours) and long-term fluctuations (i.e., on the order of months to years) in water level. 
Water quality parameters of interest that are known to affect the function of vernal ponds include temperature, pH, electrical conductivity, dissolved oxygen levels, and oxidation-reduction potential. These parameters can all be measured in situ with relatively cheap technologies and sensor networks. Some water quality parameters of interest such as some nutrient species (i.e., total Kjeldahl nitrogen) and other pollutants (i.e., emerging contaminants) require samples to be collected and brought to a laboratory for processing and analysis. 
Critical parameters that affect the ability of vernal ponds to function as appropriate habitat for breeding amphibians and the early developmental stages of tadpoles include water level, pH, and dissolved oxygen concentration. Compared to vernal ponds located in relatively pristine landscapes, elevated levels of electrical conductivity, higher pH, reduced dissolved oxygen concentrations, and high nutrient concentrations have been recorded in vernal ponds impacted by anthropogenic activities2,7. Reducing or anaerobic conditions may occur in these habitats, particularly ones that are impacted by anthropogenic activities. This can cause a shift in the microbiological community, altering the nutrient cycling within the pond and potentially reducing degradation of endocrine disrupting compounds and other pollutants8,9.
The goal of this paper is to provide information for how to establish a station for monitoring the water quantity and quality of a vernal pond. This method can be applied to any vernal pond, but requires access to the site (i.e., the site must be on public property or have land-owner permission to install equipment).

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			<td height="21" style="height:21px;width:216px;">CR1000</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">16130-23</td>
			<td style="width:415px;">Measurement and Control Datalogger</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">ENC12/14-SC-MM</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">30707-88</td>
			<td>Weatherproof Enclosure Box (12&#34; x 14&#34;)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CS451-L</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">28790-82</td>
			<td>Pressure Transducer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CM305-PS</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">20570-3</td>
			<td>47&#34; Mounting Pole (Tripod)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TE525-L</td>
			<td style="width:143px;">Texas Electronics</td>
			<td style="width:119px;">7085-111</td>
			<td>Tipping Bucket Rain Gauage (0.01 inch)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CS511-L</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">26995-41</td>
			<td>Dissolved Oxygen Sensor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">SP10</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">5278</td>
			<td>10 W Solar Panel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PS150-SW</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">29293-1</td>
			<td>12 V Power Supply with Voltage Regulator &#38; 7 Ah Rechargeable Battery</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">CSIM11-ORP</td>
			<td style="width:143px;">Wedgewood Analytical</td>
			<td style="width:119px;">22120-72</td>
			<td>Oxidation-reduction potential probe</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">CSIM11-L</td>
			<td style="width:143px;">Wedgewood Analytical</td>
			<td style="width:119px;">22119-151</td>
			<td>pH probe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">CS547A-L</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">16725-229</td>
			<td>Water conductivity probe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">A547</td>
			<td style="width:143px;">Campbell Scientific</td>
			<td style="width:119px;">12323</td>
			<td>CS547(A) Conductivity Interface</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">CST/berger SAL &#39;N&#39; Series Automatic Level Package</td>
			<td style="width:143px;">CST/berger</td>
			<td>55-SLVP32D</td>
			<td>Automatic Survey Level, Tripod, and 8&#39; survey rod</td>
		</tr>
	</tbody>
</table>

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.

Vernal ponds can exhibit a wide range of morphology, with profiles ranging from convex to straight slope to concave. Example morphology for a vernal pond in Central Pennsylvania is shown in Figure 1, along with the results of the stage-storage curve for this pond (Figure 2, Table 1). Maximum pond depth is not a strong indicator of surface area, as hydroperiod has only a weak correlation with pond morphology<sup c...

Watch this Scientific Journal Video about Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds at JoVE.com

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds

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.

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

The overall goal of this procedure is to establish a monitoring station that can continuously monitor the hydrology and water quality of a vernal pond. This method can provide insight to the functionality of vernal ponds, such as how human activities are impacting these sensitive aquatic ecosystems. The main advantage of this technique is that allows us to know at a high temporal resolution what the major water quality parameters are that maybe influencing contaminant fate and transport.Though This method can provide insight into vernal pond ecosystem and it can also be applied to other systems such as lakes or streams. Visual demonstration of this method is helpful as the setup and installation steps can be confusing when under this equipment. This video focuses on the installation of the vernal monitoring pond monitoring system.Details on surveying a vernal pond morphology and calculation of a pond's state storage curve are both provided in the text protocol. The sensors for this study this include a pressure transducer, a dissolved oxygen sensor, an oxidation reduction probe, an electrical conductivity probe, a pH probe, and a tipping bucket rain gauge. They should all be calibrated prior to the field installation.Apart from the rain gauge, secure all of their sensors to a cinder block or a wooden stake so they will stay at the bottom of the pond, or at a depth of interest. To accomplish this use hose clamps or zip ties. When doing so be sure to attach the dissolved oxygen sensor at an angle at which oxygen will diffuse across its membrane.Also, install the pressure transducer upright, so it measures the pressure of the water column above it. Position the sensors toward the center of the pond where they are unlikely to get dry during the study period. Measure and note the distance between the sensors in the deepest part of the pond, as this figure is needed for some calculations.The sensor wires are vulnerable to mice or other animals that may chew on them such as when the water level is low. So run the wire through a PVC pipe for protection. Extend the pipe to end of the pond where the wires will engage with the data-logger.Next set up the data-logger. To set up the data-logger install a tripod near the pond's edge and secure it to the ground using stakes. Attach a radio antennae if the data needs to be transmitted wirelessly.Then onto the tripod attach the data box for the data-logger and a 12 volt battery with voltage regulator. Be sure to leave room on the tripod to mount a solar panel. Next attach a 10 watt solar panel to the top of the tripod, and angle it towards the sun;use a solar angle calculator to optimize the angle.Now if there is there is room on the tripod attach a rain gauge, otherwise attach it to a wooden stake or metal pole near the edge of the pond. The rain gauge should be under the same amount of tree cover as the bulk of the pond surface area. Now set up the central data-logger, program it to record data on 15 minute intervals, feed all the sensor and solar panel wires into the enclosure box through the hole at the bottom of the box.Then connect all sensors to the wiring panel in accordance with the sensor's instructions or the wiring diagram. Next, connect the solar panel wires to the 12 volt battery to recharge the battery. Now, connect the battery to power input panel.Then place a desiccant pack inside the enclosure box to reduce the likelihood of moisture damage to the electronics. If possible test the system connected to a field laptop using the serial cable and use the software to ensure that the sensor network is working properly. Then plug the gap in the wire hole with clay to keep out insects and water.Finally, close the enclosure box. If security is a concern close the box with a padlock. Going forward visit the site frequently and follow the manufacturer's recommendations for periodic sensor calibration, which can be weekly.Vernal ponds can exhibit a wide range of morphology with profiles ranging from convex, to straight-slope, to concave. Precipitation, evapotranspiration, and ground water flow are important factors in determining the hydrology of vernal ponds. A study of three ponds was conducted during the breeding and metamorphosis period of wood frogs in the Northeastern United States.The ponds were selected because their water levels changes are caused by rainfall and by waste water irrigation events. The sensors were placed at the bottoms of the ponds. In general, the temperature of the ponds increased over the study period but decreased in response to effluent irrigation events.The pH was relatively consistent for the majority of the study period and as expected. The electrical conductivity of the ponds increased over the course of the study period likely due to higher electrical conductivity of waste water compared to rain water. Dissolved oxygen concentration and oxidation reduction potential generally followed a similar trend.Dissolved oxygen followed a common trend of being inversely related to temperature, which related to mats of duckweed that grow on these ponds during this time of year. Once mastered, this type of thing can be done in four to six hours if performed properly. Plan to spend at least half the day in the field.It's important to remember when you're doing this kind of research to secure the proper permits or landownership permissions, depending on whether you're doing on private or public property. Also don't forget that work with electricity can be extremely hazardous and that all the equipment must be properly grounded. Following this procedure, other methods like collecting ground water samples, can be performed in order to answer additional questions, like how the reflex conditions in the pond may affect the persistence of emerging contaminants and potentially, the metamorphosis of amphibians.

continuous-hydrologic-and-water-quality-monitoring-of-vernal-ponds

Research

JoVE Journal

Environment

Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration.
Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release.
The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations.

Lake eutrophication is a water quality issue worldwide, making the need to identify and control nutrient sources critical. Laboratory determination of phosphorus release rates from sediment cores is a valuable approach for determining the role of internal phosphorus loading and guiding management decisions.

Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a standardized method for use in multiple analytical laboratories during monitoring period 3 of the Unregulated Contaminant Monitoring Rule. Herein we present the protocol for extraction of viral ribonucleic acid (RNA) from water sample concentrates and for quantitatively measuring enterovirus and norovirus concentrations using reverse transcription-quantitative PCR (RT-qPCR). Virus concentrations for the molecular assay are calculated in terms of genomic copies of viral RNA per liter based upon a standard curve. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. The method has been evaluated by examining virus recovery from ground and reagent grade waters seeded with poliovirus type 3 and murine norovirus as a surrogate for human noroviruses. Mean poliovirus recoveries were 20% in groundwaters and 44% in reagent grade water. Mean murine norovirus recoveries with the RT-qPCR assay were 30% in groundwaters and 4% in reagent grade water.

Here we present a procedure to quantify enterovirus and norovirus in environmental and drinking waters using reverse transcription-quantitative PCR. Mean virus recovery from groundwater with this standardized procedure from EPA Method 1615 was 20% for poliovirus and 30% for murine norovirus.

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a ...

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. 
In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries.

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA ...

Characterization and Application of Passive Samplers for Monitoring of Pesticides in Water

Five different water passive samplers were calibrated under laboratory conditions for measurement of 124 legacy and current used pesticides. This study provides a protocol for the passive sampler preparation, calibration, extraction method and instrumental analysis. Sampling rates (RS) and passive sampler-water partition coefficients (KPW) were calculated for silicone rubber, polar organic chemical integrative sampler POCIS-A, POCIS-B, SDB-RPS and C18 disk. The uptake of the selected compounds depended on their physicochemical properties, i.e., silicone rubber showed a better uptake for more hydrophobic compounds (log octanol-water partition coefficient (KOW) &#62; 5.3), whereas POCIS-A, POCIS-B and SDB-RPS disk were more suitable for hydrophilic compounds (log KOW &#60; 0.70).

A protocol about the characterization and application of five different passive sampling devices is presented.

Five different water passive samplers were calibrated under laboratory conditions for measurement of 124 legacy and current used pesticides. This study ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

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.

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

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as redox potential (Eh) and pH, but also to microbial activities that can play a direct or indirect role on speciation and/or mobility. Indeed, some bacteria can directly oxidize As(III) to As(V) or reduce As(V) to As(III). Likewise, bacteria are strongly involved in Hg cycling, either through its methylation, forming the neurotoxin monomethyl mercury, or through its reduction to elemental Hg&#176;. The fates of both As and Hg are also strongly linked to soil or aquifer composition; indeed, As and Hg can bind to organic compounds or (oxy)hydroxides, which will influence their mobility. In turn, bacterial activities such as iron (oxy)hydroxide reduction or organic matter mineralization can indirectly influence As and Hg sequestration. The presence of sulfate/sulfide can also strongly impact these particular elements through the formation of complexes such as thio-arsenates with As or metacinnabar with Hg.
Consequently, many important questions have been raised on the fate and speciation of As and Hg in the environment and how to limit their toxicity. However, due to their reactivity towards aquifer components, it is difficult to clearly dissociate the biogeochemical processes that occur and their different impacts on the fate of these TE.
To do so, we developed an original, experimental, column setup that mimics an aquifer with As- or Hg-iron-oxide rich areas versus iron depleted areas, enabling a better understanding of TE biogeochemistry in anoxic conditions. The following protocol gives step by step instructions for the column set-up either for As or Hg, as well as an example with As under iron and sulfate reducing conditions.

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron OxyHydroxides, Trace Elements, and Bacteria

Fate and speciation of arsenic and mercury in aquifers are closely related to physio-chemical conditions and microbial activity. Here, we present an original experimental column setup that mimics an aquifer and enables a better understanding of trace element biogeochemistry in anoxic conditions. Two examples are presented, combining geochemical and microbiological approaches.

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as ...

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide (GFH), with little effort and high reliability. The phosphonate, e.g., nitrilotrimethylphosphonic acid (NTMP), is brought into contact with the GFH in a rotator in a solution buffered by an organic acid (e.g., acetic acid) or Good buffer (e.g., 2-(N-morpholino)ethanesulfonic acid) [MES] and N-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid [CAPSO]) in a concentration of 10 mM for a specific time in 50 mL centrifuge tubes. Subsequently, after membrane filtration (0.45 &#181;m pore size), the total phosphorus (total P) concentration is measured using a specifically developed determination method (ISOmini). This method is a modification and simplification of the ISO 6878 method: a 4 mL sample is mixed with H2SO4 and K2S2O8 in a screw cap vial, heated to 148-150 &#176;C for 1 h and then mixed with NaOH, ascorbic acid and acidified molybdate with antimony(III) (final volume of 10 mL) to produce a blue complex. The color intensity, which is linearly proportional to the phosphorus concentration, is measured spectrophotometrically (880 nm). It is demonstrated that the buffer concentration used has no significant effect on the adsorption of phosphonate between pH 4 and 12. The buffers, therefore, do not compete with the phosphonate for adsorption sites. Furthermore, the relatively high concentration of the buffer requires a higher dosage concentration of oxidizing agent (K2S2O8) for digestion than that specified in ISO 6878, which, together with the NaOH dosage, is matched to each buffer. Despite the simplification, the ISOmini method does not lose any of its accuracy compared to the standardized method.

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide, with little effort and high reliability. In a buffered solution, the phosphonate is brought into contact with the adsorbent using a rotator and then analyzed via a miniaturized phosphorus determination method.

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric ...

Construction of a Low-cost Mobile Incubator for Field and Laboratory Use

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, low-cost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 &#176;C - 39 &#176;C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator set-ups were also effective at moderate and low ambient temperatures (between 3.5 &#176;C and 27 &#176;C), and at high temperatures (39 &#176;C) when the incubator set temperature was higher. This incubator prototype is low-cost (&lt; 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.

This paper describes a method for building an adaptable, low-cost and transportable incubator for microbial testing of drinking water. Our design is based on widely available materials and can operate under a range of field conditions, while still offering the advantages of higher-end laboratory-based models.

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water ...