This research was funded by the U.S. Army Corps of Engineers Dredging Operations and Environmental Research Program, Todd Bridges, Director. Permission was granted by the Chief of Engineers to publish this material.

<ol>
	<li>National Research Council (NRC). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+process+for+setting,+managing,+and+monitoring+environmental+windows+for+dredging+projects.">A process for setting, managing, and monitoring environmental windows for dredging projects.</a> Marine Board, Transportation Research Board, Special Report 262. , (2001).</li><li>Suedel, B. C., Kim, J., Clarke, D. G., Linkov, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+risk-informed+decision+framework+for+setting+environmental+windows+for+dredging+projects.">A risk-informed decision framework for setting environmental windows for dredging projects.</a> Sci Total Environ. 403, 1-11 (2008).</li><li>Reine, K. J., Dickerson, D. D., Clarke, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+windows+associated+with+dredging+operations.">Environmental windows associated with dredging operations.</a> DOER Technical Notes Collection. ERDC TN DOER-E2. , (1998).</li><li>Wilber, D. H., Clarke, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+effects+of+suspended+sediments:+A+review+of+suspended+sediment+impacts+on+fish+and+shellfish+with+relation+to+dredging+activities+in+estuaries.">Biological effects of suspended sediments: A review of suspended sediment impacts on fish and shellfish with relation to dredging activities in estuaries.</a> N Am J Fish Manag. 21, 855-875 (2001).</li><li>Suedel, B. C., Lutz, C. H., Clarke, J. U., Clarke, D. G. <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+suspended+sediment+on+walleye+(Sander+vitreus)+eggs.">The effects of suspended sediment on walleye (Sander vitreus) eggs.</a> J. Soils Sediments. 12, 995-1003 (2012).</li><li>Travis, J., Kring, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> LabVIEW for Everyone: Graphical Programming Made Easy and Fun (National Instruments Virtual Instrumentation Series). , (2006).</li><li>Hazardous Waste Test Methods/SW-846 On-line. Office of Solid Waste and Emergency Response (OSWER) Available from: <a target="_blank" href="https://www.epa.gov/hw-sw846/sw-846-compendium">https://www.epa.gov/hw-sw846/sw-846-compendium</a> (2016)</li><li>Plumb, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Procedure for handling and chemical analysis of sediment and water samples, EPA/CE-81-1. , (1981).</li><li>Clarke, D. G., Wilber, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Assessment of potential impacts of dredging operations due to sediment resuspension. , (2000).</li><li>Suedel, B. C., Clarke, J. U., Lutz, C. H., Clarke, D. G., Godard-Codding, C., Maul, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suspended+sediment+effects+on+walleye+(Sander+vitreus).">Suspended sediment effects on walleye (Sander vitreus).</a> J. Great Lakes Res. 40, 141-148 (2014).</li><li>Wilkens, J. L., Katzenmeyer, A. W., Hahn, N. M., Hoover, J. J., Suedel, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laboratory+test+of+suspended+sediment+effects+on+short-term+survival+and+swimming+performance+of+juvenile+Atlantic+Sturgeon+(Acipenser+oxyrinchus+oxyrinchus).">Laboratory test of suspended sediment effects on short-term survival and swimming performance of juvenile Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus).</a> J. Appl. Ichthy. 31, 984-990 (2015).</li><li>Suedel, B. C., Clarke, J. U., Wilkens, J., Lutz, C. H., Clarke, D. G. <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+a+simulated+sediment+plume+on+eastern+oyster+(Crassostrea+virginica)+survival,+growth,+and+condition.">The effects of a simulated sediment plume on eastern oyster (Crassostrea virginica) survival, growth, and condition.</a> Estuaries and Coasts. 38 (2), 578-589 (2015).</li><li>Bilotta, G. S., Brazier, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+the+influence+of+suspended+solids+on+water+chemistry+and+aquatic+biota.">Understanding the influence of suspended solids on water chemistry and aquatic biota.</a> Water Res. 42, 2849-2861 (2008).</li><li>Reine, K., Clarke, D., Dickerson, C., Pickard, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+potential+impacts+of+bucket+dredging+plumes+on+walleye+spawning+habitat+in+Maumee+Bay,+Ohio.">Assessment of potential impacts of bucket dredging plumes on walleye spawning habitat in Maumee Bay, Ohio.</a> Proceedings of the 18th World Dredging Congress (WODCON XVIII). , (2007).</li></ol>

Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the U.S. Army. Citations of commercial organizations or trade names in this report do not constitute an official Department of the Army endorsement or approval of the products or services of these organizations. Authors Burton C. Suedel and Justin L. Wilkens, both of the US Army Engineer Research and Development Center, declare that they have no competing financial interests.

The FLEES technology improves on existing methods4,9 by maintaining and controlling suspended sediments over a wide range of exposure times and suspended sediment concentrations using an automated, computer controlled system. The technology is flexible such that it can be used to evaluate the effects of suspended sediments to multiple aquatic species and life stages of varying sizes from eggs to adults depending on the species. In the future, the technology is capable of assessing suspended sediment effects to...

Dredging operations use mechanical methods to remove bottom sediments from harbors and navigation channels. During removal, some portion of the disturbed sediment is suspended into the water column, potentially making this a source of physical stress to aquatic species. In addition to being suspended, the sediment may be transported away from the dredge by ambient conditions before settling out of the water column. The combination of these two mechanisms means that an aquatic organism occurring near an operating dredge may be exposed to suspended sediments and suffer adverse effects. To address such concerns, environmental windows (seasonal dredging restrictions) are routinely used as a management practice to reduce or eliminate risk of potentially harmful impacts of suspended sediments from dredging activities on aquatic resources1,2.
Environmental windows are most commonly established to protect endangered, threatened or commercially valuable species such as the walleye (Sander vitreus) and eastern oyster (Crassostrea virginica)3. The supporting justification for imposing environmental windows often focuses on how dredge activities may potentially physically disturb (e.g., suspended sediment) an animal&#39;s ability to complete a specific part of its life history. The life stages commonly cited are eggs and larvae for keeping migration routes open for anadromous species3. However, there is limited information concerning species-specific biological effects relevant to suspended sediment4,5 available to inform using environmental windows as a risk management tool.
For these reasons, the FLEES was designed, built, and used to simulate the suspension of sediment, and to determine its effects on early life stages of aquatic organisms. FLEES studies use fine-grained sediment particles (i.e., predominantly silts, clays, and fine sands) which are most likely to remain in suspension and migrate furthest from the source. The FLEES is capable of testing fish eggs and larvae, but it can also be retrofitted to accommodate other aquatic organisms, making it a unique capability. The resulting biological response data can then be used to assess the effects of suspended sediments. The following procedures provide an overview of how the technology can be constructed and operated to yield repeatable suspended sediment concentrations and effects data using various aquatic species.

<table><tbody><tr><td colspan="4">&lt;strong&gt;Parts List for One FLEES Module, Water Bath, and Aquarium&lt;/strong&gt;</td></tr><tr><td>post, wood - used to build module (cut to 78 in)</td><td>Local vendor</td><td>N/A</td><td>Quantity: 4&lt;br/&gt; Size: 4 in x 4 in x 8 ft</td></tr><tr><td>plywood, marine grade - fastened to wooden posts about 18 in off ground - for holding water bath (60 in x 42 in)</td><td>Local vendor</td><td>N/A</td><td>Quantity: 1&lt;br/&gt; Size: 3/4 in x 4 ft x 8 ft</td></tr><tr><td>plywood - fastened on top of wooden posts - for holding pipes, solenoids and electrical (60 in x 42 in)</td><td>Local vendor</td><td>N/A</td><td>Quantity: 1&lt;br/&gt; Size: 1/4 in x 4 ft x 8 ft</td></tr><tr><td>stud, wood - used to brace plywood and wooden posts (cut to fit)</td><td>Local vendor</td><td>N/A</td><td>Quantity: 4&lt;br/&gt; Size: 2 in x 4 in x 96 in</td></tr><tr><td>tank, fiberglass - water bath with two drains: 1) to supply chiller; and 2) to drain water</td><td>Hydro Composites, LLC, Stockdale, TX, USA</td><td>FBT-226</td><td>Quantity: 1&lt;br/&gt; Size: 150-gal</td></tr><tr><td>chiller, water with self contained pump - for water bath; chiller sits under module</td><td>Remcor Products Co., Glendale Heights, IL, USA</td><td>CFF-500</td><td>Quantity: 1&lt;br/&gt; Size: 1/2 hp</td></tr><tr><td>tank, domed bottom - FLEES aquaria - sit inside water bath</td><td>United States Plastic Corp, Lima, OH, USA</td><td>5197</td><td>Quantity: 5&lt;br/&gt; Size: 19 L</td></tr><tr><td>tank, stand - acrylic stand, 12 in x 12 in x 6 in - to hold aquaria</td><td>custom built by ERDC shops</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: custom</td></tr><tr><td>pump, magnetic drive - to suspend sediment in each aquarium</td><td>March Manufacturing Inc., Glenview, IL, USA</td><td>MDX-3-1/2 115 v</td><td>Quantity: 5&lt;br/&gt; Size: 28 liter per min</td></tr><tr><td>light, LED - installed over water bath</td><td>C2 Development, Inc., Ames, IA, USA</td><td>Hydra 26</td><td>Quantity: 2&lt;br/&gt; Size: based on area to light</td></tr><tr><td>pipe, PVC schedule 40 - installed in drain of water bath to control water level</td><td>Local vendor</td><td>N/A</td><td>Quantity: -&lt;br/&gt; Size: 1 in</td></tr><tr><td>fittings, bulkhead - for aquaria/water bath connections to pumps, drains, water and slurry lines</td><td>Lifegard Aquatics, Cerritos, CA, USA</td><td>R270900</td><td>Quantity: 30&lt;br/&gt; Size: 1/2 in FPT x FPT</td></tr><tr><td>fittings, quick-disconnect, male pipe threaded inserts - insert in tank bulkhead</td><td>Cole-Parmer, Vernon Hills, IL, USA</td><td>EW-31303-36</td><td>Quantity: 10&lt;br/&gt; Size: 1/2 in MPT</td></tr><tr><td>fittings, quick-disconnect, valved hose barbs - connection between aquarium and insert in tank bulkhead</td><td>Cole-Parmer, Vernon Hills, IL, USA</td><td>EW-31303-11</td><td>Quantity: 10&lt;br/&gt; Size: 1/2 in</td></tr><tr><td>fittings, black HDPE threaded elbow - for aquaria vinyl tube connections to slurry/water line and pump</td><td>United States Plastic Corp, Lima, OH, USA</td><td>62043</td><td>Quantity: 20&lt;br/&gt; Size: 1/2 NPT x 1/2 in Hose ID</td></tr><tr><td>fittings, black HDPE threaded adapter - for connections between pump and tank bulkhead</td><td>United States Plastic Corp, Lima, OH, USA</td><td>62017</td><td>Quantity: 10&lt;br/&gt; Size: 1/2 NPT x 1/2 in Hose ID</td></tr><tr><td>tube, vinyl - connect slurry/water line to aquaria and to connect pumps to aquaria</td><td>Local vendor</td><td>N/A</td><td>Quantity: 25 ft&lt;br/&gt; Size: 1/2 in ID</td></tr><tr><td>tube, vinyl - connect to aquaria drains inserts and water bath drain</td><td>Local vendor</td><td>N/A</td><td>Quantity: 25 ft&lt;br/&gt; Size: 5/8 in ID</td></tr><tr><td>clamp, hose, stainless steel - to clamp vinyl tube to hose barbs</td><td>Local vendor</td><td>N/A</td><td>Quantity: 40&lt;br/&gt; Size: #8</td></tr><tr><td colspan="4">&lt;strong&gt;Parts List for Slurry System&lt;/strong&gt;</td></tr><tr><td>chiller, water with self contained pump - sits off to side of slurry tank</td><td>Remcor Products Co., Glendale Heights, IL, USA</td><td>CFF-500</td><td>Quantity: 1&lt;br/&gt; Size: 1/2 hp</td></tr><tr><td>125 gallon open top cone bottom tank w/Stand - 42 in x 35 in - contains the water and sediment to make slurry</td><td>United States Plastic Corp, Lima, OH, USA</td><td>8586</td><td>Quantity: 1&lt;br/&gt; Size: 125 gal</td></tr><tr><td>Cover for 125 gallon tank</td><td>United States Plastic Corp, Lima, OH, USA</td><td>8935</td><td>Quantity: 1&lt;br/&gt; Size: 42 in x 35 in</td></tr><tr><td>valve, PVC - connect tank drain to pump - isolate for maintenance</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 2&lt;br/&gt; Size: 1-1/2 in</td></tr><tr><td>pump, double diaphragm mounted on stand - used to recirculate slurry</td><td>Wilden-pumps.co.uk &amp;amp; Air Pumping Ltd., Essex, UK</td><td>P2/PPPP/WF/WF/PTV/400</td><td>Quantity: 1&lt;br/&gt; &lt;br/&gt; contact distributor</td></tr><tr><td>sensor, optical backscatter - measure NTU in slurry tank</td><td>Campbell Scientific, Logan, UT, USA</td><td>OBS-3+</td><td>Quantity: 1&lt;br/&gt; Size: 0-1,000 NTU</td></tr><tr><td>pipe, PVC Schedule 40 - to recirculate slurry</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 20 ft&lt;br/&gt; Size: 1 in</td></tr><tr><td>pipe, flexible PVC - fitted with union and used to connect to next module</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 10 ft&lt;br/&gt; Size: 1 in</td></tr><tr><td>union, PVC Schedle 80 Socket - connect slurry line with next module</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 8&lt;br/&gt; Size: 1/2 in</td></tr><tr><td>solenoid, plastomatic (normally closed) - introduce slurry</td><td>Plast-O-Matic Valves, Inc., Cedar Grove, NJ, USA</td><td>EASYMT4V12R24-PV</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in NPT threaded, 24 VAC&lt;br/&gt; contact distributor</td></tr><tr><td>fitting, PVC tee - connect slurry pipe with solenoid</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1 in x 1 in x 1 in slip x slip x FIPT</td></tr><tr><td>fittings, 1 in PVC ball valve threaded - shut off for slurry delivery to solenoid/water lines</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 7&lt;br/&gt; Size: 1/2 in</td></tr><tr><td>fittings, 1 in PVC union threaded - connect slurry solenoid to shut off valve</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in</td></tr><tr><td>tube, vinyl - connection between water solenoid and slurry solenoid</td><td>Local vendor</td><td>N/A</td><td>Quantity: 50 ft&lt;br/&gt; Size: 1/4&quot; ID</td></tr><tr><td colspan="4">&lt;strong&gt;Parts List for Water System&lt;/strong&gt;</td></tr><tr><td>chiller, water with self contained pump - sits off to side of reservoir</td><td>Remcor Products Co., Glendale Heights, IL, USA</td><td>CFF-500</td><td>Quantity: 1&lt;br/&gt; Size: 1/2 hp</td></tr><tr><td>125 gallon open top cone bottom tank w/Stand - 42 in x 35 in - contains the water and sediment to make slurry</td><td>United States Plastic Corp, Lima, OH, USA</td><td>8586</td><td>Quantity: 1&lt;br/&gt; Size: 125 gal</td></tr><tr><td>Cover for 125 gallon tank</td><td>United States Plastic Corp, Lima, OH, USA</td><td>8935</td><td>Quantity: 1&lt;br/&gt; Size: 42 in x 35 in</td></tr><tr><td>valve, PVC - connect tank drain to water pump</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 2&lt;br/&gt; Size: 1 in</td></tr><tr><td>pump, magnetic drive, in-line use - used to recirculate water to aquaria and chiller</td><td>Little Giant, Fort Wayne, IN, USA</td><td>3-MD-SC</td><td>Quantity: 1&lt;br/&gt; Size: 1/12 hp</td></tr><tr><td>solenoid, alco - introduce water</td><td>discontinued; ASCO, Florham Park, NJ,USA for similar</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 24 v, 1/4 in NIPT</td></tr><tr><td>fittings, black HDPE reducer connector - connect 1/4 in hose water line from solenoid&amp;nbsp; to 1/2 in hose</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in hose ID x 1/4 in hose ID</td></tr><tr><td>fittings, black HDPE tee - connect 1/2 in hose water line and slurry to aquaria</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in NPT x 1/2 in hose ID x 1/2 in hose ID</td></tr><tr><td>fittings, street elbow</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in 90&amp;deg; MIPT x FIPT</td></tr><tr><td>fittings, PVC threaded pipe nipples - connect union fittings with solenoids and other connections</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 12&lt;br/&gt; Size: 1/2 in</td></tr><tr><td>fittings, union threaded - connect slurry/water lines with next module</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 6&lt;br/&gt; Size: 1 in PVC&amp;nbsp;</td></tr><tr><td>fittings, reducer bushing - connect to reducer tee in water line</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 1/2 in male by 1/4 in female FIPT</td></tr><tr><td>fittings, threaded pipe nipples - connection between bushing and water solenoid</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5&lt;br/&gt; Size: 4 in long x 1/4 in</td></tr><tr><td>pipe, PVC - make connections between tank, pump and chiller</td><td>local plumbing vendor</td><td>N/A</td><td>Quantity: 5 ft&lt;br/&gt; Size: Schedule 40</td></tr><tr><td colspan="4">&lt;strong&gt;Parts List for Sensors, Data Acquisition Device, and Computer Software&lt;/strong&gt;</td></tr><tr><td>software, LabView</td><td>National Instruments, Austin, Texas, USA</td><td>LabView 2015 Base</td><td>Quantity: 1&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI-1001 12-Slot Chassis, U.S. 120 VAC</td><td>National Instruments, Austin, Texas, USA</td><td>776571-01</td><td>Quantity: 1&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI 1100 - 32-Channel, &amp;plusmn;10 V Analog Input Module</td><td>National Instruments, Austin, Texas, USA</td><td>776572-00</td><td>Quantity: 1&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI 1303 - Terminal block designed for high-accuracy thermocouple measurements</td><td>National Instruments, Austin, Texas, USA</td><td>777687-03</td><td>Quantity: 2&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI 1102B - 32-Channel Thermocouple/Voltage Input Module</td><td>National Instruments, Austin, Texas, USA</td><td>776572-02B</td><td>Quantity: 1&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI 1161 - General-Purpose Relay Module</td><td>National Instruments, Austin, Texas, USA</td><td>776572-61</td><td>Quantity: 6&lt;br/&gt; Size: N/A</td></tr><tr><td>SCXI 1300 - General-Purpose Voltage Module</td><td>National Instruments, Austin, Texas, USA</td><td>777687-00</td><td>Quantity: 1&lt;br/&gt; Size: N/A</td></tr><tr><td>PCMCIA Card DAQCARD-AI-16E-4</td><td>National Instruments, Austin, Texas, USA</td><td>N/A - legacy</td><td>Quantity: 1&lt;br/&gt; Size: N/A&lt;br/&gt; used cards available online</td></tr><tr><td>sensor, optical backscatter - measure NTU in each aquarium</td><td>Campbell Scientific Inc., Logan, UT, USA</td><td>OBS-3+</td><td>Quantity: 5&lt;br/&gt; Size: 0-1,000 NTU</td></tr></tbody></table>

a flow-through exposure system for evaluating suspended sediments effects on aquatic life

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory by using pumps and automating delivery of sediment and water to simulate suspension of sediment. FLEES data are used to develop exposure-response curves between the effects on aquatic organisms and suspended sediment concentrations at the desired exposure duration. The effects data are used to evaluate management practices used to reduce the interactions between aquatic organisms and anthropogenic causes of suspended sediments. The FLEES is capable of generating total suspended solids (TSS) concentrations as low as 30 to as high as 800 mg/L, making this system an ideal choice for evaluating the effects of TSS resulting from many activities including simulating low ambient levels of TSS to evaluating sources of suspended sediments from dredging operations, vessel traffic, freshets, and storms.

A series of operational runs is performed before beginning an experiment to ensure that the FLEES is delivering the appropriate concentrations of sediments to each aquarium (Sections 5.5 and 6.2). Figure 6 illustrates how NTU concentrations are maintained in experimental aquaria to achieve target suspended sediment concentrations. In this example, FLEES evaluated whether suspended sediment could be maintained over a three-day period with the proposed test sediment, a dura...

Watch this Scientific Journal Video about A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life at JoVE.com

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

A robust and flexible flow-through exposure system designed to maintain sediment in suspension is presented. The system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory.

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended ...

a-flow-through-exposure-system-for-evaluating-suspended-sediments

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JoVE Journal

Environment

8.4K Views.  U.S. Army Corps of Engineers. A robust and flexible flow-through exposure system designed to maintain sediment in suspension is presented. The system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory.

Video: A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. Unfortunately, traditional benthic larval sampling methods, such as the dip-net, can be time-consuming and expensive. An alternative protocol involves collection of Chironomidae surface-floating pupal exuviae (SFPE). Chironomidae is a species-rich family of flies (Diptera) whose immature stages typically occur in aquatic habitats. Adult chironomids emerge from the water, leaving their pupal skins, or exuviae, floating on the water&#8217;s surface. Exuviae often accumulate along banks or behind obstructions by action of the wind or water current, where they can be collected to assess chironomid diversity and richness. Chironomids can be used as important biological indicators, since some species are more tolerant to pollution than others. Therefore, the relative abundance and species composition of collected SFPE reflect changes in water quality. Here, methods associated with field collection, laboratory processing, slide mounting, and identification of chironomid SFPE are described in detail. Advantages of the SFPE method include minimal disturbance at a sampling area, efficient and economical sample collection and laboratory processing, ease of identification, applicability in nearly all aquatic environments, and a potentially more sensitive measure of ecosystem stress. Limitations include the inability to determine larval microhabitat use and inability to identify pupal exuviae to species if they have not been associated with adult males.

Use of Chironomidae Diptera Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

Rapid bioassessment protocols using benthic macroinvertebrates are often used to monitor and assess water quality. An efficient protocol involves collections of Chironomidae surface-floating pupal exuviae (SFPE). Here, techniques for field collection, laboratory processing, slide mounting, and identification of Chironomidae SFPE are described.

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. ...

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.

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.

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

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.

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

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may ...

Image-based Lagrangian Particle Tracking in Bed-load Experiments

Image analysis has been increasingly used for the measurement of river flows due to its capabilities to furnish detailed quantitative depictions at a relatively low cost. This manuscript describes an application of particle tracking velocimetry (PTV) to a bed-load experiment with lightweight sediment. The key characteristics of the investigated sediment transport conditions were the presence of a covered flow and of a fixed rough bed above which particles were released in limited number at the flume inlet. Under the applied flow conditions, the motion of the individual bed-load particles was intermittent, with alternating movement and stillness terms. The flow pattern was preliminarily characterized by acoustic measurements of vertical profiles of the stream-wise velocity. During process visualization, a large field of view was obtained using two action-cameras placed at different locations along the flume. The experimental protocol is described in terms of channel calibration, experiment realization, image pre-processing, automatic particle tracking, and post-processing of particle track data from the two cameras. The presented proof-of-concept results include probability distributions of the particle hop length and duration. The achievements of this work are compared to those of existing literature to demonstrate the validity of the protocol.

The manuscript presents a protocol for the conduction of bed-load sediment transport experiments where the moving particles are tracked by image analysis. The experimental facility, the procedures for run realization and data processing, and finally some proof-of-concept results are presented here.

Image analysis has been increasingly used for the measurement of river flows due to its capabilities to furnish detailed quantitative depictions at a ...

Visualizing Hyporheic Flow Through Bedforms Using Dye Experiments and Simulation

Advective exchange between the pore space of sediments and the overlying water column, called hyporheic exchange in fluvial environments, drives solute transport in rivers and many important biogeochemical processes. To improve understanding of these processes through visual demonstration, we created a hyporheic flow simulation in the multi-agent computer modeling platform NetLogo. The simulation shows virtual tracer flowing through a streambed covered with two-dimensional bedforms. Sediment, flow, and bedform characteristics are used as input variables for the model. We illustrate how these simulations match experimental observations from laboratory flume experiments based on measured input parameters. Dye is injected into the flume sediments to visualize the porewater flow. For comparison virtual tracer particles are placed at the same locations in the simulation. This coupled simulation and lab experiment has been used successfully in undergraduate and graduate laboratories to directly visualize river-porewater interactions and show how physically-based flow simulations can reproduce environmental phenomena. Students took photographs of the bed through the transparent flume walls and compared them to shapes of the dye at the same times in the simulation. This resulted in very similar trends, which allowed the students to better understand both the flow patterns and the mathematical model. The simulations also allow the user to quickly visualize the impact of each input parameter by running multiple simulations. This process can also be used in research applications to illustrate basic processes, relate interfacial fluxes and porewater transport, and support quantitative process-based modeling.

This manuscript describes how to create regular bedforms in a flume, visualize flow through the bedforms, and use computer simulations to simulate the hyporheic flow. The computer simulations compare well with the experimental observations. This coupled simulation and experiment is well-suited for both research and educational purposes.

Advective exchange between the pore space of sediments and the overlying water column, called hyporheic exchange in fluvial environments, drives solute ...

Engineering

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.

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

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

The mechanisms underpinning the deposition of fine-grained, organic-rich sediments are still largely debated. Specifically, the impact of the interaction of clay particles with reactive, planktonic cyanobacterial cells to the sedimentary record is under studied. This interaction is a potentially major contributor to shale depositional models. Within a lab setting, the flocculation and sedimentation rates of these materials can be examined and measured in a controlled environment. Here, we detail a protocol for measuring the sedimentation rate of cyanobacterial/clay mixtures. This methodology is demonstrated through the description of two sample experiments: the first uses kaolin (a dehydrated form of kaolinite) and Synechococcus sp. PCC 7002 (a marine coccoid cyanobacteria), and the second uses kaolin and Synechocystis sp. PCC 6803 (a freshwater coccoid cyanobacteria). Cyanobacterial cultures are mixed with varying amounts of clay within a specially designed tank apparatus optimized to allow continuous, real-time video and photographic recording. The sampling procedures are detailed as well as a post-collection protocol for precise measurement of chlorophyll a from which the concentration of cyanobacterial cells remaining in suspension can be determined. Through experimental replication, a profile is constructed that displays sedimentation rate.

The interaction and sedimentation of the clay and bacterial cells within the marine realm, observed in natural environments, can be best investigated in a controlled lab environment. Here, we describe a detailed protocol, which outlines a novel method for measuring the sedimentation rate of clay and cyanobacterial floccules.

The mechanisms underpinning the deposition of fine-grained, organic-rich sediments are still largely debated. Specifically, the impact of the interaction ...

Bioindication Testing of Stream Environment Suitability for Young Freshwater Pearl Mussels Using In Situ Exposure Methods

Knowledge of habitat suitability for freshwater mussels is an important step in the conservation of this endangered species group. We describe a protocol for performing in situ juvenile exposure tests within oligotrophic river catchments over one-month and three-month periods. Two methods (in both modifications) are presented to evaluate the juvenile growth and survival rate. The methods and modifications differ in value for the locality bioindication and each has its benefits as well as limitations. The sandy cage method works with a large set of individuals, but only some of the individuals are measured and the results are evaluated in bulk. In the mesh cage method, the individuals are kept and measured separately, but a low individual number is evaluated. The open water exposure modification is relatively easy to apply; it shows the juvenile growth potential of sites and can also be effective for water toxicity testing. The within-bed exposure modification needs a high workload but is closer to the conditions of a natural juvenile environment and it is better for reporting the real suitability of localities. On the other hand, more replications are needed in this modification due to its high-hyporheic environment variability.

Bioindication Testing of Stream Environment Suitability for Young Freshwater Pearl Mussels Using In Situ Exposure Methods

In situ bioindications enable determination of the suitability of an environment for endangered mussel species. We describe two methods based on the juvenile exposure of freshwater pearl mussels in cages to oligotrophic river habitats. Both methods are implemented in variants for open water and hyporheic water environments.

Knowledge of habitat suitability for freshwater mussels is an important step in the conservation of this endangered species group. We describe a protocol ...

Quantifying Fish Swimming Behavior in Response to Acute Exposure of Aqueous Copper Using Computer Assisted Video and Digital Image Analysis

Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors.

Measuring the impacts of environmental contaminants on fish behavior is often subjective and challenging particularly when dealing with sublethal endpoints. We describe methods including video technology to quantify swimming behavior of early life stage white sturgeon (Acipenser transmontanus) during and after 96 hr acute exposures to various concentrations of copper.

Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction.  ...

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

Summary

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Chapters in this video

Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

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

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

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

Image-based Lagrangian Particle Tracking in Bed-load Experiments

Visualizing Hyporheic Flow Through Bedforms Using Dye Experiments and Simulation

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

Determination of the Settling Rate of Clay/Cyanobacterial Floccules

Bioindication Testing of Stream Environment Suitability for Young Freshwater Pearl Mussels Using In Situ Exposure Methods

Quantifying Fish Swimming Behavior in Response to Acute Exposure of Aqueous Copper Using Computer Assisted Video and Digital Image Analysis