USGS Professional Pages
RESEARCH BIOLOGISTContact Info
Dr. Iwanowicz is a research biologist at the USGS, Leetown Science Center, National Fish Health Research Laboratory in Leetown, WV. He earned his Bachelor of Science degree at the University of Massachusetts, Amherst, his Master of Science from the University of Arkansas at Pine Bluff, and his PhD from his Alma mater in 2008. His dissertation research focused on the application of resident fishes as sentinels of aquatic ecosystem health. This research included the investigation of immunomodulatory and endocrine disrupting effects of legacy chemicals including polychlorinated biphenyl mixtures on fishes, and identified an association with disease susceptibility. His research also investigated the roles estrogens, estrogen receptors as immunoregulators in fish, which led to his first book chapter in a fish immunology series.
His research involves investigations into the presence and biological effects of endocrine disrupting compounds and associated fish health issues in the Chesapeake Bay and Great Lakes Drainages in addition to National Wildlife Refuges and National Parks. This research includes the application of advanced next generation sequencing approaches to identify molecular biomarkers of immune and endocrine modulation in non-model species (resident fishes). It also includes the application of transgenic bacterial, yeast and mammalian cell bioassays to assess the presence of biologically active compounds in environmental matrices. This research requires the development and application of molecular tools that are used in conjunction with well established physiological biomarkers. Other research involves the identification of novel fish pathogens and sleuthing for pathogens in environmental matrices using molecular tools.
Dr. Iwanowicz is involved with a number of committee and team activities in the USGS Ecosystems and Environmental Health mission areas. He is also an active member of the American Fisheries Society - Fish Health Section for which he currently serves as chair of the Awards Committee. He is an associate editor of the Journal of Aquatic Animal Health, and a member of the American Society of Microbiology, International Society of Fish and Shellfish Immunology, International Society for Transgenic Technologies, and the Society of Environmental Toxicology and Chemistry.
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PublicationsJenkins J.A., R.O. Draugelis-Dale, A.E. Pinkney, L.R. Iwanowicz, and V.S. Blazer (2015) Flow cytometric method for measuring chromatin fragmentation in fixed sperm from yellow perch (Perca flavescens). Theriogenology. 83:920-931. [Link]
Fischer, J.M., Phillips, P.J., Reilly, T.J., Focazio, M.J., Loftin, K.A., Benzel, W.M., Jones, D.K., Smalling, K.L., Fisher, S.C., Fisher, I.J., Iwanowicz, L.R., Romanok, K.M., Jenkins, D., Bowers, L., Boehlke, A., Foreman, W.T., Deetz, A.C., Carper, L.G., Imbrigiotta, T.E., and Birdwell, J., (2015) Estuarine bed-sediment-quality data collected in New Jersey and New York after Hurricane Sandy, 2013: U.S. Geological Survey Data Series 905, 42 p., plus CD-ROM. [Link]
Smith, G.D., V.S. Blazer, H.L Walsh, L.R. Iwanowicz, C. Starliper, and A.J. Sperry. (2015) The effects of disease-related mortality of young-of-year Smallmouth Bass Micropterus dolomieu on population characteristics in the Susquehanna River Basin, Pennsylvania and potential implications to conservation of black bass Micropterus spp. diversity. Pages 319-332 in Tringali, M. D., M. S. Allen, T. Birdsong, and J. M. Long. 2014. Black Bass Diversity: Multidisciplinary Science for Conservation. Proceedings of the Symposium Black Bass Diversity: Multidisciplinary Science for Conservation Held in Nashville, Tennessee, February 8-10, 2013. American Fisheries Society, Bethesda, Maryland.
Densmore, C.L., L.R. Iwanowicz, A.P. Henderson, D.D. Iwanowicz, and J.S. Odenkirk (2015) Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River Catchment. Journal of Fish Diseases. In press [Link]
Hahn, CM, L.R. Iwanowicz, R.S. Cornman, C.M. Conway, J.R. Winton, and V.S. Blazer, (2015) Characterization of a Novel Hepadnavirus in the White Sucker (Catostomus commersonii) from the Great Lakes Region of the USA. Journal of Virology. In press
Iwanowicz, L.R., V.S. Blazer, A.E. Pinkney, C.P. Guy, A.M. Major, K. Munney, S. Mierzykowski, S. Lingenfelser, A. Secord, K. Patnode, T.J. Kubiak, C. Stern, C.M. Hahn, D.D. Iwanowicz, H.L. Walsh, and A. Sperry (2015) Evidence of estrogenic endocrine disruption in smallmouth and largemouth bass inhabiting Northeast U.S. National Wildlife Refuge waters: a reconnaissance study. Ecotoxicology and Environmental Safety. 124:50-59. [Link]
Bradley, P. W. Battaglin, L. Iwanowicz, J. Clark, and C. Journey (2015) Aerobic Biodegradation Potential of Endocrine Disrupting Chemicals in Surface-Water Sediment at Rocky Mountain National Park. Environmental Toxicology and Chemistry. In press
Gorelick, DA., L.R. Iwanowicz, A.L. Hung, V.S. Blazer and M.E. Halpern (2014) Tissue-specific estrogen receptor activation in response to environmental endocrine disruptors. Environmental Health Perspectives. 122: 356-362. [Link]
Blazer, V.S., P.M. Mazik, L.R. Iwanowicz, R. Braham, C. Hahn, H.L. Walsh, and A. Sperry (2014) Monitoring of wild fish health at selected sites in the Great Lakes Basin—Methods and preliminary results: U.S. Geological Survey Open-File Report 2014–1027, 44 p [Link]
Blazer, VS, D.D. Iwanowicz, H.L. Walsh, A.J. Sperry, L.R. Iwanowicz, D.A. Alvarez, R.A. Brightbill, G. Smith and R. Manning (2014) Reproductive Health of Fishes in Pennsylvania Watersheds: Association with Chemicals of Emerging Contaminants. Environmental Monitoring and Assessment. 186:6471-6491. [Link]
Duffy, T.A. L.R. Iwanowicz, and S.D. McCormick (2014) Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar. Aquatic Toxicology. 152C:1-10. [Link]
Ottinger, C.A., D.C. Honeyfield, C.L. Densmore, and L.R. Iwanowicz (2014) In vitro immune function in thiamine-replete and -depleted Lake Trout (Salvelinus namaycush). Fish & Shellfish Immunology. 38:211-220. [Link]
Young, J, L. Iwanowicz, V. Blazer, and A. Sperry (2014) A landscape-based reconnaissance survey of estrogenic activity in streams of the upper Potomac, upper James, and Shenandoah Rivers, USA. Environmental Monitoring and Assessment. [Link]
Blazer, V.S., P.M. Mazik, L.R. Iwanowicz, R. Braham, C. Hahn, H.L. Walsh, and A. Sperry (2014). Assessment of the fish tumor beneficial use impairment in brown bullhead (Ameiurus nebulosus) at selected Great Lakes Areas of Concern. U.S. Geological Survey Open-File Report 2014-1105, 17 p. [Link]
Iwanowicz, L.R., J. Stafford, R. Patino, E. Bengten, N.W. Miller, and V. Blazer (2014) Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens. Fish & Shellfish Immunology. 40: 109-119. [Link]
Iwanowicz, L, C Densmore, C Hahn, P McAllister and J Odenkirk (2013) Identification of Largemouth Bass Virus in the Introduced Northern snakehead (Channa argus) inhabiting the Chesapeake Bay Watershed. Journal of Aquatic Animal Health. 25:191-196. [Link]
Starliper, C., VS Blazer, LR Iwanowicz, and HL Walsh (2013) Bacterial etiology in diseased fishes, primarily smallmouth bass Micropterus dolomieu, within the Chesapeake Bay drainage in 2009-2011. Proceedings of the West Virginia Academy of Science. 85(2)
Iwanowicz, DD, L.R. Iwanowicz, E.W. Howerth, W.B Schill, V.S. Blazer and R. Johnson (2013) Characterization of Myxobolus stanlii n sp. (Myxozoa: Myxobolidae: Myxosporea) in largescale stonerollers (Campostoma oligolepis) from the Mobile River Basin. Journal of Parasitology. 99:102-111
Kolpin, DW, VS Blazer, JL Gray, MJ Focazio, JA Young, DA Alvarez, LR Iwanowicz, WT Foreman, ET Furlong, GK Speiran, SD Zaugg, LE Hubbard, MT Meyer, MW Sandstrom, LB Barber (2013) Chemical Contaminants in Water and Sediment near fish nesting sites in the Potomac River Basin: Determining Potential Exposures to Smallmouth Bass (Micropterus dolomieu). Science of the Total Environment. 443C: 700-716 [Link]
Blazer, VS, AE Pinkney, JA Jenkins, LR Iwanowicz, S Minkkinen, RO Draugelis-Dale and JH Uphoff (2013) Reproductive Health of Yellow Perch Perca flavescens in Selected Tributaries of the Chesapeake Bay. Science of the Total Environment. 447:198-209 [Link]
Iwanowicz. D.D., L.R. Iwanowicz, N. Hitt, T.L. King (2013) Differential expression profiles of miRNA in the Little Brown Bat (Myotis lucifugus) associated with White Nose affected and unaffected individuals. U.S. Geological Survey Open-File Report 2013–1099, 11 p., [Link]
Ekman, DR, GT Ankley, VS Blazer, TW Collette, N Garcia-Reyero, LR Iwanowicz, ZG Jorgenson, KE Lee, PM Mazik, DH Miller, EJ Perkins, ET Smith, JE Tiege and D Villeneuve (2013) Biological Effects-based Tools for Monitoring Impacted Surface Waters in the Great Lakes: A Multiagency Program in Support of the Great Lakes Restoration Initiative. Environmental Practice. 15: 409-426. [Link]
Starliper, C., VS Blazer, LR Iwanowicz, and HL Walsh. (2013) Bacterial etiology in diseased fishes, primarily smallmouth bass Micropterus dolomieu, within the Chesapeake Bay drainage in 2009-2011. Proceedings of the West Virginia Academy of Science. 85(2):18-32
Iwanowicz, L.R., Blazer, V.S., Hitt, N.P., McCormick, S.D., DuVault, D.S., Ottinger, C.A. (2012) Histologic, Immunologic and Endocrine Biomarkers Indicate Contaminant Effects in Fishes of the Ashtabula River. Ecotoxicology. 21(1): 654-182. [Link]
Stavreva, DA, P Klausmeyer, AA George, L Varticovski, D Sack, TC Voss, RL Schiltz, VS Blazer, LR Iwanowicz, and GL Hager (2012) Prevalent Glucocorticoid and Androgen Activity in US Water Sources. Scientific Reports. 2: 937 [Link]
Walsh, HL, VS Blazer, LR Iwanowicz, G Smith (2012) A Redescription of Myxobolus inornatus from Young-of-the-Year Smallmouth Bass Micropterus dolomieu. Journal of Parasitology. 98:1236-1242 [Link]
Ottinger, C.A., D. Honeyfield, C.L. Densmore, L.R. Iwanowicz. (2012) Impact of Thiamine Deficiency on T-cell Dependent and T-cell Independent Antibody Production in Lake Trout (Salvelinus namaycush). Journal of Aquatic Animal Health. 24: 258-273. [Link]
Walsh, HL, LR Iwanowicz, GW Glenney, DD Iwanowicz, VS Blazer (2012) Description of Two New Gill Myxozoans from Smallmouth (Micropterus dolomieu) and Largemouth (M. salmoides) Bass. Journal of Parasitology. 98: 415-422. [Link]
Ciparis, S, LR Iwanowicz and JR Voshell (2012) Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams. Science of the Total Environment, 414: 268-276. [Link]
Iwanowicz, LR and VS Blazer (2011) A brief overview of estrogen-associated endocrine in fishes: evidence of effects on reproductive and immune physiology. In: R. C. Cipriano, A. Bruckner and I. S. Shchelkunov, Editors, Aquatic Animal Health: A Continuing Dialogue Between Russia and The United States. Proceedings of the Third Bilateral Conference Between the United States and Russia: Aquatic Animal Health 2009. July 12-20, 2009. Shepherdstown, WV. Michigan State University, East Lansing, Michigan. [Link]
Blazer, V.S., Iwanowicz, L.R., Henderson, H., Mazik, P.M., Jenkins, J.A., Alvarez, D.A., and Young, J.A. (2011) Reproductive endocrine disruption in smallmouth bass (Micropterus dolomieu) in the Potomac River basin: spatial and temporal comparisons of biological effects Environmental Monitoring and Assessment, 184: 4309-4334. [Link]
Bykova, L., S.A. Archer-Hartmann, L.A. Holland, L.R. Iwanowicz, and V.S. Blazer (2010) Steroid determination in fish plasma using capillary electrophoresis. Environmental Toxicology and Chemistry 29:1950-1956. [Link]
Blazer, V.S., L.R. Iwanowicz, C.E. Starliper, D.D. Iwanowicz, P. Barbash, J.D. Hedrick, S.J. Reeser, J.E. Mullican, S.D. Zaugg, M.R. Burkhardt and J. Kelble (2010) Mortality of Centrarchids in the Potomac Drainage: Survey of Results and Overview of Potential Contributing Factors. Journal of Aquatic Animal Health 22: 190-218. [Link]
Ripley, J.L, L.R. Iwanowicz, V.S. Blazer and C.M. Foran. (2009) Author’s Response to If Poultry's to Blame, Where's the Proof? Environmental Toxicology and Chemistry. 28: 908-909.
Alvarez, D.A., Cranor, W.L., Perkins, S.D., Schroeder, V., Iwanowicz, L.R., Clark, R.C., Guy, C.P., Pinkney, A., Blazer, VS. (2009) Reproductive Health of Bass in the Potomac Drainage: 2) Seasonal Occurrence of Persistent and Emerging Organic Contaminants. Environmental Toxicology and Chemistry. 28: 1084-1095. [Link]
Iwanowicz, L.R., Blazer, V.S., Guy, C.P., Pinkney, A.E. Mullican, J. and Alvarez. D.A. (2009) Reproductive Health of Bass in the Potomac Drainage: 1) Biological Effects of Wastewater Treatment Plant Effluent. Environmental Toxicology and Chemistry. 28: 1072-1083. [Link]
Robertson, L.S., Iwanowicz, L.R., and Marranca, J.M. (2009) Identification of Centrarchid Hepcidins and Evidence that 17β-Estradiol Disrupts Constitutive Expression of Hepcidin-1 and Inducible Expression of Hepcidin-2 in Largemouth Bass. Fish & Shellfish Immunology. 26; 898–907.
Iwanowicz, L.R., V.S. Blazer, S.D. McCormick, P. Van Veld, C.A. Ottinger. (2009) Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus. Aquatic Toxicology. 93: 70-82.
Iwanowicz, L.R., D.D. Cartwright, L.M. Pote, V.S. Blazer, W.B. Schill (2008) Morphology and 18S rDNA of Henneguya gurlei (Myxosporea) from Ameiurus nebulosus (Siluriformes) in North Carolina, USA. Journal of Parasitology. 94: 46-57.
Ripley, J.L, L.R. Iwanowicz, V.S. Blazer and C.M. Foran. (2008) Utilization of Protein Profiles as Indicators of Environmental Impairment of Smallmouth Bass (Micropterus dolomieu) from the Shenandoah River, VA, USA. Environmental Toxicology and Chemistry. 27: 1756-1767.
Blazer,V.S., L.R. Iwanowicz, D.D. Iwanowicz, D.R. Smith, J.A. Young, J. Hedrick, S. W. Foster, S. J. Reeser. (2007) Intersex (Testicular Oocytes) in Smallmouth Bass Micropterus dolomieu From the Potomac River and Selected Nearby Drainages. Journal of Aquatic Animal Health. 19: 242-253.
Iwanowicz, L.R., A.R. Griffin, D.D. Cartwright, V.S. Blazer (2006) Mortality and pathology in brown bullheads Amieurus nebulosus associated with a spontaneous Edwardsiella ictaluri outbreak under tank culture conditions. Diseases of Aquatic Organisms. 70: 219-225.
Iwanowicz,L.R., D.T. Lerner, V.S. Blazer and S.D. McCormick (2005) Aqueous Exposure to Aroclor 1254 Modulates the Mitogenic Response of Atlantic Salmon Anterior Kidney T-cells: indications of short- and long-term immunomodulation. Aquatic Toxicology. 72: 305-314.
Densmore, C., C.A. Ottinger, V.S. Blazer L.R. Iwanowicz and David R. Smith (2004) Immunomodulation and disease resistance in postyearling rainbow trout (Oncorynchus mykiss) infected with Myxobolus cerebralis, the causative agent of whirling disease. Journal of Aquatic Animal Health. 16: 73-82.
Iwanowicz, L., L Brown, B Eltz, F Juanes and J Murt (2004) Book Review. In a Perfect Ocean: The state of fisheries and ecosystems in the North Atlantic Ocean. Reviews in Fish Biology and Fisheries.14: 149-151.
Iwanowicz, L., C Densmore and C Ottinger (2004) Calcein AM released-based cytotoxic cell assay for fish leucocytes. Fish & Shellfish Immunology 16: 127 - 137.
McIntire, M., L R Iwanowicz and A E Goodwin (2003) Molecular, physical and clinical evidence that Golden Shiner Virus (GSV) and Grass Carp Reovirus (GCRV) are variants of the same virus. Journal of Aquatic Animal Health. 15: 257-263.
Densmore, C.L., C.A. Ottinger, V.S. Blazer and L.R. Iwanowicz (2002). Immunomodulation and disease resistance in Myxobolus cerebralis infected rainbow trout. Proceedings of the 8th Annual Whirling Disease Symposium.
Iwanowicz, L.R. and A E Goodwin (2002) Characterization of a new bacilliform fathead minnow rhabdovirus that produces syncytia in tissue culture. Archives of Virology 147: 889 – 916.
Iwanowicz, L.R. A E Goodwin and J Harshbarger (2001) Embryonal rhabdomyosarcoma of the giant gourami, Colisa fasciata (Bloch & Schneider). Journal of Fish Diseases 24:177-179. [Link]
Iwanowicz, L.R. A E Goodwin and N Heil (2000) A small RNA virus isolated from apparently healthy wild sandbar shiners, Notropis scepticus. Journal of Fish Diseases 23: 349-352. [Link]
Iwanowicz, L.R and C.A. Ottinger (2009) Estrogens, Estrogen Receptors and Their Role as Immunoregulators in Fish. In Fish Defenses, Volume 1: Immunology. Eds. G. Zaccone, J. Meseguer, A. Garcia-Ayala, and B.G. Kapoor. Science Publishers, Enfield, NH, USA. Pp. 277-322.
My USGS Science Strategy AreasUnderstanding Ecosystems & Predicting Ecosystems Change
The Role of Environment and Wildlife in Human Health
11649 Leetown Road
Kearneysville, WV 25430
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