This work was funded, in part, by the Great Lakes Fishery Commission and the Annis Water Resources Institute. Use of trade, product, or firm names does not imply endorsement by the U. S. Government. This article is Contribution 1867 of the U. S. Geological Survey Great Lakes Science Center.

1. Laboratory Experiment
<ol>
	<li>Obtain the prey fish to be fed to the predator fish during the experiment. Preferably these prey fish should be captured in the field, frozen, and stored at about -30 &#176;C. Consider commercial fishing operations as a potential source for the prey fish.</li>
	<li>Introduce the predator fish into the laboratory tanks to be used for the experiment. Up to 15 predator fish have been introduced into each of 870-L tanks, and up to 30 predator fish have been introduced into each of 2,380-L...

<ol>
	<li>Madenjian, C. P., Carpenter, S. R., Rand, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+are+the+PCB+concentrations+of+salmonine+individuals+from+the+same+lake+so+highly+variable?.">Why are the PCB concentrations of salmonine individuals from the same lake so highly variable?.</a> Canadian Journal of Fisheries and Aquatic Sciences. 51 (4), 800-807 (1994).</li><li>Madenjian, C. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Net+trophic+transfer+efficiency+of+PCBs+to+Lake+Michigan+coho+salmon+from+their+prey.">Net trophic transfer efficiency of PCBs to Lake Michigan coho salmon from their prey.</a> Environmental Science and Technology. 32 (20), 3063-3067 (1998).</li><li>Thomann, R. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioaccumulation+model+of+organic+chemical+distribution+in+aquatic+food+chains.">Bioaccumulation model of organic chemical distribution in aquatic food chains.</a> Environmental Science and Technology. 23 (6), 699-707 (1989).</li><li>Calabrese, E. J., Baldwin, L. 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> Performing ecological risk assessments. , (1993).</li><li>Madenjian, C. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Variation+in+net+trophic+transfer+efficiencies+among+21+PCB+congeners.">Variation in net trophic transfer efficiencies among 21 PCB congeners.</a> Environmental Science and Technology. 33 (21), 3768-3773 (1999).</li><li>Jackson, L. J., Schindler, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Field+estimates+of+net+trophic+transfer+of+PCBs+from+prey+fishes+to+Lake+Michigan+salmonids.">Field estimates of net trophic transfer of PCBs from prey fishes to Lake Michigan salmonids.</a> Environmental Science and Technology. 30 (6), 1861-1865 (1996).</li><li>Gobas, F. A. P. C., Muir, D. C. G., Mackay, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamics+of+dietary+bioaccumulation+and+faecal+elimination+of+hydrophobic+organic+chemicals+in+fish.">Dynamics of dietary bioaccumulation and faecal elimination of hydrophobic organic chemicals in fish.</a> Chemosphere. 17 (5), 943-962 (1988).</li><li>Madenjian, C. P., O&#8217;Connor, D. V., Rediske, R. R., O&#8217;Keefe, J. P., Pothoven, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Net+trophic+transfer+efficiencies+of+polychlorinated+biphenyl+congeners+to+lake+whitefish+(Coregonus+clupeaformis)+from+their+food.">Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake whitefish (Coregonus clupeaformis) from their food.</a> Environmental Toxicology and Chemistry. 27 (3), 631-636 (2008).</li><li>Isosaarl, P., Kiviranta, H., Lie, &. #. 2. 1. 6. ;., Lundebye, A. K., Ritchie, G., Vartiainen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accumulation+and+distribution+of+polychlorinated+dibenzo-p-dioxin,+dibenzofuran,+and+polychlorinated+biphenyl+congeners+in+Atlantic+salmon+(Salmo+salar).">Accumulation and distribution of polychlorinated dibenzo-p-dioxin, dibenzofuran, and polychlorinated biphenyl congeners in Atlantic salmon (Salmo salar).</a> Environmental Toxicology and Chemistry. 23 (7), 1672-1679 (2004).</li><li>Buckman, A. H., Brown, S. B., Hoekstra, P. F., Solomon, K. R., Fisk, A. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicokinetics+of+three+polychlorinated+biphenyl+technical+mixtures+in+rainbow+trout+(Oncorhynchus+mykiss).">Toxicokinetics of three polychlorinated biphenyl technical mixtures in rainbow trout (Oncorhynchus mykiss).</a> Environmental Toxicology and Chemistry. 23 (7), 1725-1736 (2004).</li><li>Burreau, S., Axelman, J., Broman, D., Jakobsson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dietary+uptake+in+pike+(Esox+lucius)+of+some+polychlorinated+biphenyls,+polychlorinated+naphthalenes+and+polybrominated+diphenyl+ethers+administered+in+natural+diet.">Dietary uptake in pike (Esox lucius) of some polychlorinated biphenyls, polychlorinated naphthalenes and polybrominated diphenyl ethers administered in natural diet.</a> Environmental Toxicology and Chemistry. 16 (12), 2508-2513 (1997).</li><li>Madenjian, C. P., DeSorcie, T. J., Stedman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ontogenic+and+spatial+patterns+in+diet+and+growth+of+lake+trout+in+Lake+Michigan.">Ontogenic and spatial patterns in diet and growth of lake trout in Lake Michigan.</a> Transactions of the American Fisheries Society. 127 (2), 236-252 (1998).</li><li>Paterson, G., Whittle, D. M., Drouillard, K. G., Haffner, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Declining+lake+trout+(Salvelinus+namaycush)+energy+density:+are+there+too+many+salmonid+predators+in+the+Great+Lakes?.">Declining lake trout (Salvelinus namaycush) energy density: are there too many salmonid predators in the Great Lakes?.</a> Canadian Journal of Fisheries and Aquatic Sciences. 66 (6), 919-932 (2009).</li><li>Madenjian, C. P., O&#8217;Connor, D. V., Nortrup, D. 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+new+approach+toward+evaluation+of+fish+bioenergetics+models.">A new approach toward evaluation of fish bioenergetics models.</a> Canadian Journal of Fisheries and Aquatic Sciences. 57 (5), 1025-1032 (2000).</li><li>Madenjian, C. P., Pothoven, S. A., Kao, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reevaluation+of+lake+trout+and+lake+whitefish+bioenergetics+models.">Reevaluation of lake trout and lake whitefish bioenergetics models.</a> Journal of Great Lakes Research. 39 (2), 358-364 (2013).</li><li>Madenjian, C. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+a+lake+whitefish+bioenergetics+model.">Evaluation of a lake whitefish bioenergetics model.</a> Transactions of the American Fisheries Society. 135 (1), 61-75 (2006).</li><li>Madenjian, C. P., O&#8217;Connor, D. V., Chernyak, S. M., Rediske, R. R., O&#8217;Keefe, 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=Evaluation+of+a+chinook+salmon+(Oncorhynchus+tshawytscha)+bioenergetics+model.">Evaluation of a chinook salmon (Oncorhynchus tshawytscha) bioenergetics model.</a> Canadian Journal of Fisheries and Aquatic Sciences. 61 (4), 627-635 (2004).</li><li>Madenjian, C. P., David, S. R., Rediske, R. R., O&#8217;Keefe, 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=Net+trophic+transfer+efficiencies+of+polychlorinated+biphenyl+congeners+to+lake+trout+(Salvelinus+namaycush)+from+its+prey.">Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey.</a> Environmental Toxicology and Chemistry. 31 (12), 2821-2827 (2012).</li><li>Madenjian, C. P., O'Connor, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laboratory+evaluation+of+a+lake+trout+bioenergetics+model.">Laboratory evaluation of a lake trout bioenergetics model.</a> Transactions of the American Fisheries Society. 128 (5), 802-814 (1999).</li><li>Ballschmiter, K., Bacher, R., Mennel, A., Fischer, R., Riehle, U., Swerev, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+determination+of+chlorinated+biphenyls,+chlorinated+dibenzodioxins,+and+chlorinated+dibenzofurans+by+GC-MS.">The determination of chlorinated biphenyls, chlorinated dibenzodioxins, and chlorinated dibenzofurans by GC-MS.</a> HRC Journal of High Resolution Chromatography. 15 (4), 260-270 (1992).</li><li>Madenjian, C. P., David, S. R., Pothoven, S. 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+activity+and+energy+budget+balancing+algorithm+on+laboratory+performance+of+a+fish+bioenergetics+model.">Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model.</a> Transactions of the American Fisheries Society. 141 (5), 1328-1337 (2012).</li><li>Lieb, A. J., Bills, D. D., Sinnhuber, R. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accumulation+of+dietary+polychlorinated+biphenyls+(Aroclor+1254)+by+rainbow+trout.">Accumulation of dietary polychlorinated biphenyls (Aroclor 1254) by rainbow trout.</a> Journal of Agricultural and Food Chemistry. 22 (4), 638-642 (1974).</li><li>Niimi, A. J., Oliver, B. 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+half-lives+of+polychlorinated+biphenyl+(PCB)+congeners+in+whole+fish+and+muscle+of+rainbow+trout+(Salmo+gairdneri).">Biological half-lives of polychlorinated biphenyl (PCB) congeners in whole fish and muscle of rainbow trout (Salmo gairdneri).</a> Canadian Journal of Fisheries and Aquatic Sciences. 40 (9), 1388-1394 (1983).</li><li>Gobas, F. A. P. C., Wilcockson, J. B., Russell, R. W., Haffner, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+biomagnification+in+fish+under+laboratory+and+field+conditions.">Mechanism of biomagnification in fish under laboratory and field conditions.</a> Environmental Science and Technology. 33 (1), 133-141 (1999).</li><li>Dmitrovic, J., Chan, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+polychlorinated+biphenyl+congeners+in+human+milk+by+gas+chromatography+&#8211;+negative+chemical+ionization+mass+spectrometry+after+sample+clean-up+by+solid-phase+extraction.">Determination of polychlorinated biphenyl congeners in human milk by gas chromatography &#8211; negative chemical ionization mass spectrometry after sample clean-up by solid-phase extraction.</a> Journal of Chromatography B. 778 (1-2), 147-155 (2002).</li><li>Zorn, M. E., Gibbons, R. D., Sonzogni, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Weighted+least-squares+approach+to+calculating+limits+of+detection+and+quantification+by+modeling+variability+as+a+function+of+concentration.">Weighted least-squares approach to calculating limits of detection and quantification by modeling variability as a function of concentration.</a> Analytical Chemistry. 69 (15), 3069-3075 (1997).</li></ol>

For the most accurate estimates of &#947;, the experimenter must be able to accurately track both the amount of food placed in each of the tanks and the amount of uneaten food in each of the tanks during the course of the experiment. To accomplish this, the experimenter must be able to remove all of the uneaten food from the tanks and accurately determine its weight. In addition to accurate tracking of the food actually eaten by the predator fish, accurate estimation of &#947; may also depend on sufficient duration of th...

Of all of the factors affecting the rate at which fish accumulate contaminants, the efficiency with which fish retain contaminants from the food that they eat is one of the most important1-3. Risk assessment models have been developed to predict future risks to both people and wildlife eating contaminated fish under various scenarios of environmental contamination, and the reliability of these predictions critically depends on the accuracy of the estimates of the efficiency at which fish retain contaminants from their food4.
The efficiency with which the contaminant in the food ingested by the predator is transported through the gut wall is known as gross trophic transfer efficiency5. A portion of the quantity of the contaminant transported through the gut wall of the predator may eventually be lost through depuration and/or metabolic transformation. The efficiency with which the contaminant in the food ingested by the predator is retained by the predator, including any losses due to elimination and metabolic transformation, is known as net trophic transfer efficiency6.
Gross trophic transfer efficiency of organic contaminants to fish from their prey appears to vary with the contaminant&#8217;s chemical properties, including lipid affiliation as measured by the octanol-water partition coefficient, Kow3,7. According to an empirical relationship developed by Thomann3, gross trophic transfer efficiency is relatively high when log Kow is equal to a value between 5 and 6. Gross trophic transfer efficiency declines exponentially at a rate of 50% per unit of log Kow as log Kow increases from 6 to 10, according to the Thomann3 relationship.
Nevertheless, the gross and net trophic transfer efficiencies of polychlorinated biphenyl (PCB) congeners to fish from their prey do not appear to follow the Thomann3 relationship in most cases. Although the trophic transfer efficiencies of PCB congeners to lake whitefish (Coregonus clupeaformis) from its food followed the relationship proposed by Thomann8, trophic transfer efficiencies of PCB congeners were either just weakly related or not related at all to log Kow for Atlantic salmon (Salmo salar)9, rainbow trout (Oncorhynchus mykiss)10, coho salmon (Oncorhynchus kisutch)11, and northern pike (Esox lucius)11.
The overall goal of this study was to present a laboratory technique for estimating the net trophic transfer efficiencies of PCB congeners to a piscivorous fish from its prey. Lake trout (Salvelinus namaycush) was chosen as the piscivorous fish for our experiment because lake trout are relatively easy to maintain in laboratory tanks. Bloater (Coregonus hoyi) was selected as the prey fish to be fed to the lake trout because bloater is eaten by lake trout in its natural setting12. In addition, we determined whether the net trophic transfer efficiencies for lake trout estimated from our laboratory experiment followed the Thomann3 relationship. We also determined whether the degree of activity by the lake trout had a significant effect on net trophic transfer efficiency (&#947;) of the PCB congeners. Activity by lake trout in the Laurentian Great Lakes is believed to have recently increased because changes in the food webs have caused lake trout to allocate more energy toward searching for food13. Lake trout were forced to exercise in one set of tanks by subjecting these lake trout to relatively high flow rates, whereas the other lake trout were permitted to remain relatively inactive by subjecting them to relatively low flow rates. Finally, the specific details of our laboratory procedure that need to be carefully followed to ensure the highest degree of accuracy in the &#947; estimates and to make the laboratory results applicable to the field are discussed, as well as future directions for research building on our laboratory technique. Net trophic transfer efficiency can be estimated both in the laboratory and in the field, and advantages and disadvantages are associated with both approaches. Accuracy in the estimate of &#947; depends on the accuracy of the estimate of food consumption. The amount of food eaten by fish in the laboratory can be accurately determined when proper protocols are followed, whereas the amount of food eaten by fish in the field is typically estimated via bioenergetics modeling. Use of bioenergetics modeling to derive the amount of food eaten has the potential to introduce a substantial amount of uncertainty into the estimates of food consumption. Fish bioenergetics models have been shown to estimate food consumption with no detectable bias for the case of lake trout14,15, but considerable bias in bioenergetics model estimates of food consumption has been detected for the case of lake whitefish15,16. On the other hand, estimates of net trophic transfer efficiency estimated in the laboratory may not be applicable to the field due to a difference in feeding rates between the laboratory and the field17. Evidence from both the laboratory and the field suggest that feeding rate can influence &#947;14,17.
The methodology used in the present study for estimating &#947; in the laboratory is applicable to situations where the predator fish is fed prey fish, and the amount of prey fish eaten by the predator can be accurately tracked. To accomplish this, the experimenter must weigh all of the food before placement in the tank; and the experimenter must be able to remove all of the uneaten food from the tank, and then weigh the uneaten food. In addition, an adequate suite of mixers and blenders should be available to obtain a sufficient degree of homogenization of the samples of both predator and prey fish. Finally, the gas chromatography &#8211; mass spectrometry instrumentation used to determine the PCB congener concentrations must be capable of detecting and quantifying individual PCB congeners at relatively low concentrations.

<table border="0" cellpadding="0" cellspacing="0" width="632">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">Name&#160;</td>
			<td style="width:87px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">870-L fiberglass tanks</td>
			<td style="width:87px;">Frigid Units</td>
			<td style="width:119px;">RT-430-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">2,380-L fiberglass tanks</td>
			<td style="width:87px;">Frigid Units</td>
			<td style="width:119px;">RT-630-1</td>
			<td></td>
		</tr>
		<tr height="68">
			<td height="68" style="height:68px;width:259px;">Tricaine methanesulfonate (Finquel)</td>
			<td style="width:87px;">Argent Chemical Laboratories, Inc.</td>
			<td style="width:119px;">C-FINQ-UE-100G</td>
			<td style="width:167px;">Eugenol could also be used as an anesthetic.</td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:259px;">Ashland chef knife</td>
			<td style="width:87px;">Chicago Cutlery</td>
			<td style="width:119px;">SKU 1106336</td>
			<td></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:259px;">Cutting board</td>
			<td style="width:87px;">Williams-Sonoma</td>
			<td style="width:119px;">3863586</td>
			<td></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:259px;">Hobart verical mixer (40 quart)</td>
			<td style="width:87px;">Hobart Corporation</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:259px;">1.9-L food processor</td>
			<td style="width:87px;">Robot Coupe, Inc.</td>
			<td style="width:119px;">RSI 2Y1&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Polyethylene bags (various sizes)</td>
			<td style="width:87px;">Arcan Inc.</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">I-Chem jars</td>
			<td style="width:87px;">I-Chem</td>
			<td style="width:119px;">220-0125</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:259px;">Top-load electronic balance</td>
			<td style="width:87px;">Mettler Toledo</td>
			<td style="width:119px;">Mettler PM 6000&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">Sodium sulfate, anhydrous - granular</td>
			<td style="width:87px;">EMD</td>
			<td style="width:119px;">SX0760E-3</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Glass extraction thimbles (45 mm x 130 mm)</td>
			<td style="width:87px;">Wilmad-Lab Glass</td>
			<td style="width:119px;">LG-7070-114</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">Teflon boiling chips</td>
			<td style="width:87px;">Chemware</td>
			<td style="width:119px;">919120</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">Rapid Vap nitrogen sample concentrator</td>
			<td style="width:87px;">Labconco</td>
			<td style="width:119px;">7910000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">N-Vap nitrogen concentrator</td>
			<td style="width:87px;">Organomation</td>
			<td style="width:119px;">112</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Soxhlet extraction glassware (500 mL)</td>
			<td style="width:87px;">Wilmad-Lab Glass</td>
			<td style="width:119px;">&#160;LG-6900-104</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Hexane</td>
			<td style="width:87px;">Burdick &#38; Jackson&#160;</td>
			<td style="width:119px;">Cat. 211-4</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Dichloromethane</td>
			<td style="width:87px;">Burdick &#38; Jackson&#160;</td>
			<td style="width:119px;">Cat. 300-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">Silica gel</td>
			<td style="width:87px;">BDH</td>
			<td style="width:119px;">Cat. BDH9004-1KG</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Labl Line 5000 mult-unit extraction heater</td>
			<td style="width:87px;">Lab Line Instruments</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:259px;">Agilent 5973 GC/MS with chemical ionization</td>
			<td style="width:87px;">Agilent</td>
			<td style="width:119px;">5973N</td>
			<td></td>
		</tr>
		<tr height="52">
			<td height="52" style="height:52px;width:259px;">Internal standard solution&#160;</td>
			<td style="width:87px;">Cambridge Isotope Laboratories</td>
			<td style="width:119px;">EC-1410-1.2</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">PCB congener calibration standards</td>
			<td style="width:87px;">Accustandard</td>
			<td style="width:119px;">C-CSQ-SET</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:259px;">DB-XLB column (60m x 0.25mm, 0.25 micron)</td>
			<td style="width:87px;">Agilent/ J&#38;W</td>
			<td style="width:119px;">122-1262</td>
			<td></td>
		</tr>
	</tbody>
</table>

laboratory estimation of net trophic transfer efficiencies of pcb congeners to lake trout (salvelinus namaycush) from its prey

A technique for laboratory estimation of net trophic transfer efficiency (&#947;) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is described herein. During a 135-day laboratory experiment, we fed bloater (Coregonus hoyi) that had been caught in Lake Michigan to lake trout (Salvelinus namaycush) kept in eight laboratory tanks. Bloater is a natural prey for lake trout. In four of the tanks, a relatively high flow rate was used to ensure relatively high activity by the lake trout, whereas a low flow rate was used in the other four tanks, allowing for low lake trout activity. On a tank-by-tank basis, the amount of food eaten by the lake trout on each day of the experiment was recorded. Each lake trout was weighed at the start and end of the experiment. Four to nine lake trout from each of the eight tanks were sacrificed at the start of the experiment, and all 10 lake trout remaining in each of the tanks were euthanized at the end of the experiment. We determined concentrations of 75 PCB congeners in the lake trout at the start of the experiment, in the lake trout at the end of the experiment, and in bloaters fed to the lake trout during the experiment. Based on these measurements, &#947; was calculated for each of 75 PCB congeners in each of the eight tanks. Mean &#947; was calculated for each of the 75 PCB congeners for both active and inactive lake trout. Because the experiment was replicated in eight tanks, the standard error about mean &#947; could be estimated. Results from this type of experiment are useful in risk assessment models to predict future risk to humans and wildlife eating contaminated fish under various scenarios of environmental contamination.

Lake trout showed a substantial amount of growth during the experiment, as the initial lake trout mean weights ranged from 694 to 907 g while the final lake trout mean weights ranged from 853 to 1,566 g (Table 1). The average amount of food consumed by a lake trout during the course of the 135-day experiment ranged from 641 to 2,649 g. Mean PCB congener concentrations in the lake trout increased during the experiment, as mean PCB congener concentrations ranged from 0.01 to 7.14 ng/g (wet-weight basis) at...

Watch this Scientific Journal Video about Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey at JoVE.com

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey

A technique for laboratory estimation of net trophic transfer efficiency of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is presented. To maximize applicability of the laboratory results to the field, the piscivorous fish should be fed prey fish that are typically eaten in the field.

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey

A technique for laboratory estimation of net trophic transfer efficiency (&#947;) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from ...

laboratory-estimation-net-trophic-transfer-efficiencies-pcb-congeners

Research

JoVE Journal

Environment

10.9K Views.  U. S. Geological Survey. A technique for laboratory estimation of net trophic transfer efficiency of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is presented. To maximize applicability of the laboratory results to the field, the piscivorous fish should be fed prey fish that are typically eaten in the field.