51st Annual Conference on Great Lakes Research Book of Abstracts May 19th - 23rd, 2008 Trent University Peterborough, Ontario, Canada Waters r he INTERNATIONAL ASSOCIATION FOR fo d GREAT LAKES RESEARCH e S t c u i e t i n t c s e n I T r ty en si t Univer Note to Abstract Readers: This document is an enhanced Adobe Acrobat PDF with embedded bookmarks for the first author abstracts and indices to enable easy navigation and location of desired material. This document is best viewed using Adobe Reader 8, but is compatible with Adobe Reader 5 and above. Using Bookmarks: The bookmarks are divided into three sections, 1. Abstract – by First Author: Click “plus” symbol to expand the list of bookmarks. Then clicking on author’s name bookmark will go directly to page with the author’s abstract. 2. Index – Author: Click “plus” symbol to expand list of bookmarks. Page numbers in the bookmark indicate location of author’s abstract. Clicking author’s name bookmark goes to the author index page. Use Adobe Reader’s page navigation tools to go directly to desired page. 3. Index – Subject Matter: Click “plus” symbol to expand the list of bookmarks. Page numbers in the bookmark indicate location of a subject matter within the abstracts. Clicking the subject matter bookmark goes to subject matter index page. Use Adobe Reader’s page navigation tools to go directly to desired page. International Association for Great Lakes Research – Abstracts 51st Annual Conference ABDELOUAHAB, N.1, MERGLER, D.1, TAKSER, L.2, VANIER, C.1, ST-JEAN, M.1, BALDWIN, M.1, SPEAR, P.A.3, and CHAN, H.M.4, 1CINBIOSE, Université du Québec à Montréal (UQÀM), Montreal, QC, H3C 3P8, Canada; 2Centre TOXEN, Université du Québec à Montréal (UQÀM), Montreal, QC, H3C 3P8, Canada; 3Département Obstétrique Gynécologie, Université de Sherbrooke, Sherbrooke, QC, J1H 5N4, Canada; 4University of British Columbia, British Columbia, Canada. Gender Differences in the Effects of Organochlorines, Mercury, and Lead on Thyroid Hormone Levels in Lakeside Communities of Quebec (Canada). Environmental chemicals can disrupt thyroid hormone (TH) homeostasis. However studies differ with respect to thyroid profile changes and gender differences are rarely examined. This study investigated the THs in relation to serum organochlorines (OCs), bioindicators of mercury (Hg) and blood lead (Pb) in 211 freshwater fish consumers in Canada. THs were within the normal range and the bioindicators of exposure were low compared to other reports on fish consumers. Stratified analysis showed significant gender differences. For women, serum T3 levels were negatively related to serum concentrations of PCB-138, PCB-153, non-coplanar congeners, Arochlor 1260, and ΣPCB, as well as p,p’-DDE. No relations were observed between T4 and any of the chemicals measured, but TSH was negatively related to blood Pb. For men, serum T4 was inversely related to PCB 138, dioxin-like PCBs and ΣPCB. A significant positive relation was observed between serum TSH and PCB 180, non coplanar congeners, mono-ortho coplanar congeners, dioxin-like PCBs as well as ΣPCB. Serum TSH increased with hair and blood Hg concentrations. No associations were observed for T3 in men. These findings suggest that even at low concentrations, these environmental contaminants can interfere with thyroid status and effects differ by gender. Keywords: Bioindicators, Human health, PCBs. ADAMS, J.M.1, HINCHEY, E.K.1, HORVATIN, P.J.2, and WARREN, G.J.2, 1Illinois-Indiana Sea Grant College Program, Purdue University, Liaison to U.S. EPA GLNPO, 77 W. Jackson Blvd., G-17J, Chicago, IL, 60604; 2U.S. Environmental Protection Agency Great Lakes National Program Office (GLNPO), 77 W. Jackson Blvd., G-17J, Chicago, IL, 60604. U.S. EPA Great Lakes National Program Office Nearshore Monitoring Using the Triaxus Towed Instrument Platform. Nearshore monitoring is an important factor in assessing the ecosystem health of the Great Lakes, but it often presents a challenge due to the limited availability of research vessels and difficulty in surveying the extensive (>10,000 miles) shoreline. The U.S. EPA Great Lakes National Program Office (GLNPO) recently acquired a Triaxus 3D towed undulating vehicle that will be deployed from the R/V Lake Guardian in all five Great Lakes in waters as shallow as 20 m to gain more insight into nearshore water quality and habitat characteristics. This state of the art towed instrument platform will provide real- time multiparameter profile data of the nearshore water column over a large shoreline distance as well as supplement the GLNPO open water surveys. Details of the Triaxus specifications, the various sensors it will house, and preliminary sampling locations will be presented. Keywords: Monitoring, Habitats, Water quality. 1 International Association for Great Lakes Research – Abstracts 51st Annual Conference ADLERSTEIN, S.A.1, NALEPA, T.F.2, and VANDERPLOEG, H.A.2, 13010 Dana Building, 440 Church St., Ann Arbor, MI, 48109-1041; 22205 Commonwealth Blvd., Ann Arbor, MI, 48105-2945. Zebra Mussel Impacts on the Lower Food Web in Saginaw Bay, Lake Huron: 1990-1996. We characterized temporal-spatial trends in phytoplankton, zooplankton, and benthos in Saginaw Bay prior to zebra mussel invasion, over peak densities and stabilization. We used density data of main taxonomic groups quantified during a bay-wide NOAA-Great Lakes Environmental Research Laboratories monitoring program and generalized linear models. Zebra mussels were first found in 1991, reached peaks from 1992 to 1994 depending on location, and later remained at more stable levels. Densities were higher in stations with harder substrates. Phytoplankton and zooplankton declined uniformly within the bay consistent with the zebra mussel invasion. Densities of all phytoplankton groups declined starting in 1991 or within the next three years. The most immediate and noticeable decrease was for cyanophytes with disappearance of photosensitive species. Densities recovered during the study period except for cyanophytes and chlorophytes. All zooplankton groups declined after 1990 and showed some recovery. While cyclopoids and cladocerans exhibited lowest densities in 1993, calanoids and rotifers continued to decline until 1995. Macroinvertebrate trends differed by group and substrate, and mussel effects are harder to demonstrate. Results are invaluable to understand invasion responses at the ecosystem levels and to design future monitoring. Keywords: Exotic species, Zooplankton, Lake Huron. AHMED, S. and TROY, C.D., 550 Stadium Mall Dr., West Lafayette, IN, 47907-2051, United States. Hydrodynamic Modeling of Large Stratified Lakes. An unstructured, three dimensional, finite volume, non-hydrostatic numerical model is being adapted to study wind- and thermal-forced circulation in lakes. We apply the modified model to the idealized case of an unsteady, wind-forced, stratified large circular lake, following the test case of Beletsky et al. (J. Phys. Ocean. 1997). The hydrodynamic code, SUNTANS (Stanford Unstructured Nonhydrostatic Terrain Adaptive Navier-Stokes Simulator), uses a z-level coordinate system and adaptive mesh refinement, and has been used successfully elsewhere in the simulation of stratified coastal flows. We apply the model in a parallelized configuration for a range of horizontal and vertical resolutions, discussing the results in the context of planned Lake Michigan simulations that will highlight circulation patterns and thermal features along the Indiana-Illinois lakeshore. Keywords: Atmosphere-lake interaction, Hydrodynamics, Hydrodynamic model. ALLENDER, C.J. and WILHELM, S.W., Department of Microbiology, The University of Tennessee, Knoxville, TN, 37996. Identifying the Source of Unknown Microcystin Genes and Predicting Microcystin Variants by Linking Multi-gene Diversity within Uncultured Individual Cyanobacteria. While multiple phylogenetic markers have been used to study microcystin producing cyanobacteria, in only a few instances have multiple markers been studied within individual cells, and in all cases these have been cultured isolates. Linking genes along individual microcystin (mcy) synthetase operons from uncultured cells would allow for the prediction of toxin variants and provide a better 2 International Association for Great Lakes Research – Abstracts 51st Annual Conference diagnostic for species identity. Because of the inability to cultivate many microcystin-producers, it was imperative to develop these culture-independent methods. We employed a long-PCR method and lambda vector cloning to isolate large DNA fragments (>6 kb) encompassing both mcyA2 and mcyB1 gene regions. Using a combination of phylogenetic analyses and bioinformatic prediction, the condensation domain of mcyA2 and the adenylation domain of mcyB1 were examined. These data allowed for the comparison of individual uncultured cells to the database of partial mcyA gene sequences as a query of diversity among microcystin-producers while simultaneously predicting microcystin variants. Initial efforts have been to predict the toxins produced by a mcyA-genotype termed “Microcystis-like” that is pervasive in Lakes Erie and Ontario. Preliminary results have suggested that at least a portion of these organisms produce the LR variant of microcystin. Keywords: Microcystis, Genetics, Great Lakes basin. ANDERSON, E.J.1, SCHWAB, D.J.1, HOLTSCHLAG, D.J.2, and LANG, G.A.1, 1NOAA-Great Lakes Environmental Research Laboratory, 2205 Commonwealth Blvd., Ann Arbor, MI, 48105; 2USGS - Michigan Water Science Center,