NOAA Great Lakes Seminar Series: 2006 Past Seminars

Tuesday
December 19

Speaker: Dr. Marco Costantini
NRC Associate, NOAA-GLERL

Abstract:
Bioenergetics models, designed for processing spatially-explicit environmental and biological data, were used to estimate the effects of hypoxia on potential growth and habitat quality of fish predators; i.e., walleye in Lake Erie and striped bass in Chesapeake Bay. In both systems, both positive and negative effects of hypoxia on predators were observed. Specifically, hypoxia reduces potential growth in deoxygenated waters and enhances predation efficiency/prey vulnerability by forcing prey in oxygenated surface waters. In Lake Erie, our results suggest that the recent reappearance of hypoxia in the central basin may only minimally influence the walleye habitat quality. In Chesapeake Bay, our findings have led us to speculate that hypoxia actually may indirectly benefit striped bass by increasing susceptibility of their fish prey, and that hypoxia may initially have played a role in the recovery of striped bass during the mid-1980s. Examples of how the interplay between the hypoxia-driven effects could impact the management of economically and ecologically important fish stocks are given.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/costantini/20061219.wmv
Slides:
ftp://ftp.glerl.noaa.gov/webcast/2006/costantini/20061219.pdf

Thursday
December 7

Title: "CFD modeling and simulation of ballast water exchange"

Speaker: Dr. David F. Reid
Physical Scientist, GLERL

Abstract:
Computational fluid dynamics (CFD) methods were used to model the flow behavior inside a ballast tank from a 35,000 dwt Great Lakes bulk carrier during flow-through ballast water exchange (BWE), and to investigate the use of CFD to predict and analyze BWE effectiveness. A CFD model based on a commercial viscous flow solver, Fluent (Fluent, Inc.) was applied to the ballast tank architecture from a Great Lakes bulk carrier. First, a 1/3-scale physical model of a portion of the ballast tank was built and used for validation experiments using Laser Induced Fluorescent techniques. The CFD model predictions are compared to the physical model experimental data obtained for three different conditions (ballast and exchange water densities and exchange flow rates). Based on the results to date, the CFD model predictions compare favorably with the experimental data but would not be sufficient for regulatory use related to ballast exchange efficiency analyses. An uncertainty analysis needs to be performed to determine confidence limits for the experimental data. The way the CFD model handles mixing needs to be evaluated and possibly modified, as does the grid structure. A CFD model-based simulation of a three-volume ballast water exchange in the full scale tank will be presented in computer animation format.

Tuesday
November 14

Title: "Linking landscape and water quality in the Mississippi River basin for 200 years "

Speaker: Dr. Eugene Turner, Louisiana State University

Abstract:
The world’s second largest zone of coastal hypoxia (oxygen depleted waters usually without marine organisms) is on the northern Gulf of Mexico continental shelf, adjacent to the outflows of the Mississippi and Atchafalaya Rivers. Decades of research, monitoring and retrospective analyses support the conclusion that land use in the watershed is reflected in the ecology of the continental shelf. Nitrogen loading in the Mississippi River at New Orleans is moving towards a situation encouraging N and Si limitation. This result will likely alter phytoplankton community composition, and may compromise diatom -> zooplankton -> fish food webs. It is clear that nitrogen reductions in the sub-basins of the upper Midwest will be a key to the success of government polices to reduce hypoxia, and scientists are playing a unique and important role in informing this policy process. The Action Plan developed by State, Federal and Tribal entitles identifies a quantitative goal for a reduced hypoxic zone -- a 30% reduction in the nitrogen load. The Plan recognizes that all nitrogen sources should be included in the strategy and includes other nutrients. However, because 74% of the nitrate load is from agricultural non-point sources, and because 56% of the total nitrate load comes from north of the Ohio River, it is clear that nitrogen reductions in the sub-basins of the upper Midwest will be a key to its implementation.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/turner/20061114a.wmv (intro)
ftp://ftp.glerl.noaa.gov/webcast/2006/turner/20061114b.wmv

Tuesday
November 7

Title: "Station/formation keeping mini-buoy for use in a wireless networked buoy array"

Speaker: Dr. John Vesecky, Emeritus Professor
Atmospheric, Oceanic, and Space Sciences, University of Michigan

Abstract:
Persistent ocean observations with high time and space resolution as well as extent have long been a goal for ocean observation systems. We present the design and prototype test of a propelled mini-buoy that can move at speeds of about 20 cm/s for extended periods while making ocean measurements, storing the data and communicating with neighboring buoys in a wireless networked, mini-buoy array. GPS allows knowledge of geographical position and a digital compass indicates orientation and tilt. This capability can be used to keep geographical station to GPS accuracy (several meters or less) in surface currents as high as 20 cm/s for a few days and possibly more. Alternatively propulsion can be used for formation keeping in a moving array as well as changing the array configuration. Higher positional accuracy (< 1 m) relative to other buoys in the array is possible through collective processing of GPS pseudo range data from all buoys in an array. Communication of data over long distances would be via a "mother buoy" or vessel near a mini-buoy array. The buoy is about a meter long and remains largely submerged to reduce wind-forced movement. Low power consumption was a goal throughout the design. The sensor complement for this prototype is governed by general interest as well as its initial application to ocean surface truth for airborne hyperspectral sensors in collaboration with the Airborne Sensors Group at NASA Ames Research Center. Ocean color and related measurements are emphasized. The sensors included in the prototype enable measurements of the solar irradiance at the ocean surface, upwelling hyperspectrum (256 bands from 300 to 900 nm), SST and buoy internal temperature, 10-20,000 Hz hydrophone, 3-axis accelerometers and tilt sensors for wave measurements and a GPS and digital compass for navigation. A 1 GB flash memory card allows significant storage of data on board. The fiberglass buoy structure is composed of three pods connected by vertical spars with the communication and some sensor electronics in the top pod, control and sensor electronics in the middle pod and batteries and some sensor equipment in the bottom pod. The pod and spar construction is intended to reduce drag. Propulsion is by two 2 Watt DC motors that are controlled to determine the direction and speed of motion for geographic or relative station keeping. Communication for this prototype is short range using 900 MHz (802.11) wireless technology. This report emphasizes the design, testing and demonstration of this prototype as well as plans for wireless networked, mini- buoy arrays and an initial application to harmful algal blooms in Monterey Bay.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/vesecky/20061107a.wmv (intro)
ftp://ftp.glerl.noaa.gov/webcast/2006/vesecky/20061107b.wmv
Slides:
ftp://ftp.glerl.noaa.gov/webcast/2006/vesecky/20061107.pdf

Wednesday
November 1

Title: "Ecological consequences of hypoxia in coastal systems: case studies of Lake Erie, Chesapeake Bay, and the northern Gulf of Mexico"

Speaker: Dr. Stuart Ludsin
Research Fishery Biologist, NOAA/GLERL

Abstract:
Seasonal hypoxia (<2 mg O2/L) is a common feature of many coastal systems throughout the world. In turn, because all metazoans require oxygen to survive, reduced oxygen availability would be expected to have a large impact on aquatic organisms and their interactions. Although numerous investigations have demonstrated both direct and indirect effects of bottom hypoxia on benthic organisms, our understanding of how hypoxia influences pelagic organisms remains largely enigmatic. During the past decade, I (and my colleagues) have been exploring the potential ecological effects of bottom hypoxia in three coastal systems, Chesapeake Bay (1995-2000), the Northern Gulf of Mexico (2003-2006), and Lake Erie (2005), using sophisticated instrumentation (fish acoustics towed in parallel with a sensor package consisting of an optical plankton counter, fluorometer, oxygen sensor, PAR sensor, and CTD) that can provide high-resolution maps of how pelagic organisms and their habitat are distributed throughout the water column across large spatial scales. Herein, I present findings from these investigations, highlighting generalities among systems. Most notably, I demonstrate how oxygen availability can influence the horizontal distribution of both pelagic zooplankton and fish, and as well as how hypoxia can disrupt normal vertical migration behaviors. I also demonstrate through both statistical and spatially-explicit modeling approaches how hypoxia can potentially negatively impact pelagic fishes by indirectly mediating habitat suitability (i.e., preferred food and temperature resources).

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/ludsin/20061101a.wmv (intro)
ftp://ftp.glerl.noaa.gov/webcast/2006/ludsin/20061101.wmv
slides:
ftp://ftp.glerl.noaa.gov/webcast/2006/ludsin/20061101.pdf

Monday
October 30

Title: "Simulating ice-ocean downscaling characteristics in the Beaufort-Chukchi seas using an IARC Coupled Ice-Ocean Model (CIOM)"

Speaker: Dr. Jia Wang, Research Professor
International Arctic Research Center (IARC),
University of Alaska-Fairbanks

Abstract:
An IARC regional CIOM (Coupled Ice-Ocean Model) based on POM was used to simulate the downscaling ice and ocean processes with 3.4-km resolution. The Beaufort Sea CIOM was nested to the CCSR/NIES/FRCGC high-resolution (1/6 x 1/4 degrees) global coupled atmosphere-sea ice-ocean-land model. Atmospheric forcing data were derived from NCEP reanalysis. Simulation of the seasonal cycle was conducted. In the Chukchi Sea, the Bering inflow separates into three branches: the first main branch flowing along Alaska’s coast is the Alaska Coastal Water (ACW); the second branch flows northward and turns to the right, joining the ACW along the Beaufort coast; and the third branch flows toward the Northwind Ridge. The Beaufort Gyre is well reproduced, superimposed by numerous mesoscale eddies, with anticyclones outnumbering cyclones. Downscaling sea ice dynamics was investigated, such as sea ice ridging, rafting, leads and landfast ice, which are not resolved in the previous coarse resolution model. This approach combining the global model for the 20th century climate simulation with the regional downscaling/nesting simulation helps understanding of both large-scale sea ice variability and small-scale sea ice dynamics. Sea ice breaks up offshore piece by piece with landfast ice untouched along the Beaufort Sea coast. Sea ice cracks from pack ice with irregular shapes are due to 1) complex ocean circulation, coastal current, and mesoscale eddies, 2) multi-category sea ice dynamics, and 3) complex and high-resolution geometry and topography. Sea ice ridging, rafting, and openings/leads are well reproduced in sea ice thickness and concentration. Model validation using in situ observations, satellite measurements, and historical datasets was also conducted.

A further application of CIOM to ice-related ecosystem modeling is underway in the Bering Sea and will lead to an IARC 3-D Physical (ice-ocean)-Ecosystem (biogeochemical) Model (PhEcoM), which consists of a 9-compartment model and a 4-compartment sea ice algae model. Another application of CIOM is to establish a nowcast/forecast system, such as in the Bohai Sea and northern Yellow Sea, China.

Tuesday
October 25

UofM SPHII

Title:"Brominated flame retardants: what we know, and what we don’t"

Speaker: Linda S. Birnbaum, Experimental Toxicology Division, National Health and Environmental Research Laboratory, United States Environmental Protection Agency - Research Triangle Park, NC

Abstract:
Brominated flame retardants (BFRs) represent a large and diverse class of high volume industrial chemicals which have been developed to provide fire safety. There are many other BFRs which have been used and are under development. Historically, polybrominated biphenyls (PBBs) were used but they were banned because of their persistence, bioaccumulation, and toxicity. Some of these are being detected in environmental samples. The three major BFRs in use today are tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and the polybrominated diphenyl ethers (PBDEs), which involves three commercial mixtures, Penta, Octa, and the only one still in production, Deca. TBBPA is the largest volume chemical and is used both as an additive and reactive flame retardant, primarily in electronics. It has moderate persistence, little bioaccumulation, and relatively low concern for toxicity, although it may have some endocrine disrupting properties. HBCD is also used in electronics, but is more persistent and bioaccumulative. Its isomeric composition changes as it undergoes fate, transport, and metabolism. It is found in increasing concentrations in wildlife and human samples, and there is growing concern for its potential toxicity. The PBDEs are also additive BFRs, but their properties and uses differ. Penta was used largely in polyurethane foam; Octa in office equipment; and Deca in polymers for electronic equipment and textile backings. Increasing concentrations of PBDE congeners have been found in environmental samples, wildlife, and people. The congeneric profile in biota differs from that in the commercial mixtures. The major pathways to human exposure are uncertain, although both dust and food are likely. Penta and Octa have been banned in Europe, and production withdrawn in the US, in part because of growing concern for their toxicity, including enzyme induction, endocrine disruption, and developmental reproductive and neurotoxicity. Deca is the major use PBDE product worldwide. Recent studies have demonstrated that it can be broken down in the environment by light and microbes, and metabolically in mammals. Some concerns for its toxicity, or that of its breakdown products, come from reports of its carcinogenicity in two year rodent studies and developmental neurotoxicity. Recently, it has been detected in wildlife and people. Alternatives are being suggested and use. Questions remain about their safety, as well as that of the existing BFRs. (This abstract does not reflect Agency policy.)

Tuesday
October 24

Title: "Predicting coastal hypoxia: applications of Occham's Razor."

Speaker: Dr. Don Scavia, Professor of Natural Resources and Environment at the University of Michigan, Director of the Michigan Sea Grant Program, and Interim Director of the Cooperative Institute for Limnology and Ecosystems Research.

Abstract:
To be useful, hypoxia forecast models should be scaled to the spatial and temporal frames of decision makers. It is also important to understand and quantify the certainty in such models before they can be used in forecasts and as a basis for estimating ecological impact. We have successfully applied a very simple model formulation for predicting hypoxia extent in the Chesapeake Bay and the northern Gulf of Mexico, and will describe their basis, application, and testing. The strengths and weaknesses of simple vs. more complex models will be discussed in the context of their utility for forecasts and for supporting impact assessment.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/scavia/20061024a.wmv (intro)
ftp://ftp.glerl.noaa.gov/webcast/2006/scavia/20061024.wmv
Slides:
ftp://ftp.glerl.noaa.gov/webcast/2006/scavia/20061024.pdf

Monday
October 23

Speaker: Dr. Sergei Rodionov, Joint Institute for the Study of the Atmosphere and Ocean,
University of Washington, Seattle, Washington

Abstract:
Progress in seasonal-to-interannual ice cover directly depends on our understanding of the mechanisms linking ice cover with major modes of atmospheric circulation. Recent research shows that these mechanisms may manifest themselves differently on different time scales. Using the Bering Sea as an example, a conceptual model has been developed to explain the relationship between ice cover and storm tracks and how this relationship has varied with respect to the phase of the Pacific Decadal Oscillation (PDO). The results of this work have important implications for the Great Lakes. Both the Bering Sea and Great Lakes are located close the zero correlation lines of surface air temperature response to such oscillations as the PDO and El Niño - Southern Oscillation (ENSO). In both cases this suggests not the absence of linkages, but rather strongly non-linear relationships. For example, there is a statistically significant association between mild winters in the Great Lakes basin and strong El Niño events. However, during weak or moderate El Niño events, winters in the Great Lakes tend to be much colder than normal. Another area of a potential improvement in the long-rage forecasting of ice cover is the ability to detect climate regime shifts as soon as possible. A new method is presented that signals a possibility of a regime shift in a near real time. Due to teleconnections, ice cover forecasting involves numerous relationships between climatic variables in various parts of the world. In order to utilize this information effectively, a knowledge management system (KMS) has been developed. It is demonstrated how the KMS can be used to store and retrieve the information, handle the uncertainty in the relationships, create the influence diagram for the target variable (ice cover) and estimate its future value along with the confidence (or probability) of the forecast.

Thursday
October 19

Title: "The global hazards of eutrophication and hypoxia"

Speaker: Robert Diaz, Virginia Institute of Marine Science

Abstract:
Development associated with human populations has led to the globalization of many environmental problems. In marine systems, the most serious of these problems are directly related to the process of eutrophication. The increased production of organic matter in these marine systems associated with eutrophication is the primary factor impacting species abundance and composition and dissolved oxygen budgets. Oxygen, which is essential to maintaining balance in ecosystem processes through its role in mediating microbial and metazoan activities, has declined to critically low levels in many systems, which has led to the development of hypoxia (<2 ml O2/l) and anoxia (0 ml O2/l). Currently, most oxygen depletion events are seasonal, but trends toward longer periods that could eventually lead to persistent hypoxic or anoxic conditions are emerging. Over the last 50 years, there has been an increase in the number of systems reporting problems associated with low dissolved oxygen. Currently there are close to 200 hypoxic/anoxic areas around the globe, ranging in size from <1 km2 to 70000 km2, that exhibit a graded series of responses to oxygen depletion, ranging from no obvious change to mass mortality of bottom fauna. Ecosystems currently severely stressed by eutrophicationinduced hypoxia continue to be threatened with the loss of fisheries, loss of biodiversity, alteration of food webs, and simplification of energy flows.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/diaz/20061019a.wmv
ftp://ftp.glerl.noaa.gov/webcast/2006/diaz/20061019b.wmv
PowerPoint:
ftp://ftp.glerl.noaa.gov/webcast/2006/diaz/20061019.pdf

Thursday
October 5

Title: "Submerged treasure? New evidence about the economic value of contaminated site remediation"

Speaker: Dr. John B. Braden
Department of Agricultural & Consumer Economics
University of Illinois at Urbana-Champaign

Abstract:
The daunting costs of cleaning up legacy toxic sites have hampered progress. There has been relatively little evidence of the potential for offsetting economic benefits. Thirty-one locations in U.S. waters of the Great Lakes Basin are among the languishing toxic sites. This presentation reports preliminary findings about the potential economic value to homeowners near two of these sites, Sheboygan River, WI and Buffalo River, NY. The analyses draw on both market and survey data. The findings indicate that full remediation should lead to substantial increases in nearby residential property values and the property tax base. When considered together with other economic studies of aquatic and terrestrial contaminated sites, these results strengthen our ability to generalize about the economic value of cleanup.

Thursday
September 21

Speaker: Mr. George Leshkevich
Research Physical Scientist, NOAA/GLERL

Abstract:
During the 1997 winter season, shipborne polarimetric backscatter measurements of Great Lakes (freshwater) ice types using the Jet Propulsion Laboratory (JPL) C-band scatterometer, together with surface-based ice physical characterization measurements and environmental parameters were acquired concurrently with RADARSAT and ERS-2 SAR data. This polarimetric data set, composed of over 20 ice types or variations measured at incident angles from 0o to 60o for all polarizations, was processed to radar cross-section and establishes a library of signatures (look-up table) for different ice types to be used in the computer classification of calibrated satellite synthetic aperture radar (SAR) data. Computer analysis of ERS-2 and RADARSAT ScanSAR images of Great Lakes ice cover using a supervised classification technique indicates that different ice types in the ice cover can be identified and mapped and that wind speed and direction can have a strong influence on the backscatter from open water.

Wednesday
September 20

Speaker: Dr. R.E. Hecky, United Nations University Chair in African Great Lakes and Rivers, Biology Department
University of Waterloo

Abstract:
There are only two districts of Great Lakes in the world, the Laurentian and the African Great Lakes, and together they hold over 60% of the globe’s liquid fresh water. The ancient African lakes are remarkable for endemism in their fishes and biota. Their large surface areas and volumes of water support many ecosystem services and resource extractions directly by millions of people, but as great basins they also accumulate the material wastes of the activities of those people. Nearly all the lakes are internationally shared by nations within their catchments and downstream, and consequently require international agreements for their management. All the lakes to different degrees, share or have shared several stresses in common such as eutrophication, contamination by persistent pollutants, disruptive species introductions and climate change. Despite having some common stressors, the sensitivities and responses of the lakes can differ markedly. Comparative studies of the lakes can have value to aquatic scientists and resource managers responsible for individual lakes by challenging unstated assumptions and favored models of lake processes and by evaluating different approaches to solving common problems.

Thursday
September 14

This seminar was part of the NOAA/ University of Michigan Great Lakes and Human Health Seminar Series.

Title: "Progress made in development of a multi-compartment mercury model for the Great Lakes Region"

Speaker: Dr. Elsie Sunderland
U.S. Environmental Protection Agency
Office of Research and Development
National Center for Environmental Research

Abstract:
Over the past several years, the International Joint Commission, working with the USEPA, NOAA and Environment Canada, and with several interested state and provincial parties, in particular the Ontario Ministry of the Environment has tracked and supported the development of models simulating the behaviour of mercury in the environment. The first stage of this work was dedicated to the development and verification of the NOAA-HYSPLIT atmospheric deposition model. The results of this work can be seen in the International Air Quality Advisory Board segments of the 1999/2001 and 2001/2003 Great Lakes Priority Reports available on the International Joint Commission website. More recently, the focus of this work has moved toward an attempt to develop a linked sequence of models to track the fate of mercury from its initial release into the larger environment and its substantial distribution into waterbodies, sediments, subsequent bioaccumulation and ultimate uptake by humans. Results from an initial application using the HYSPLIT atmospheric fate and transport model integrated with coupled environmental fate and food-web bioaccumulation models for Lake Ontario will be presented. Probabilistic human exposure modeling using the MENTOR modeling system will also be discussed. This talk will focus on an overview of some of the key areas of uncertainty in the relationships between mercury emissions, deposition and concentrations in the sediments, water, fish and human exposure highlighted by the application of each sub-model to Lake Ontario. Finally, information on mercury fate and transport in the Great Lakes Regions compiled by the IJC through a series of technical meeting will be reviewed and ongoing research, data collection efforts, and model improvements will be discussed.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/sunderland/20060914.wmv
PDF:
ftp://ftp.glerl.noaa.gov/webcast/2006/sunderland/20060914.pdf

Wednesday
August 30

Speaker: Dr. Wayne S. Gardner
Professor, The University of Texas Marine Science Institute, Port Aransas, Texas

Abstract:
Denitrification and DNRA are dissimilatory heterotrophic nitrate reduction processes, which occur at the sediment-water interface in coastal or other aquatic environments. Denitrification converts nitrate-N into the relatively inert N_2, whereas DNRA converts it to NH₄⁺, an N form that can be re-assimilated by plants and bacteria. Denitrification has been measured in a variety of freshwater and marine systems but DNRA has not been considered as often, in part because measurement is cumbersome. Nitrogen transformations, relative to oxygen consumption rates, were examined in a variety of shallow coastal marine and lake systems. Concentration changes of nutrients and gases between inflow and outflow waters were measured as site water was passed continuously over intact cores before and after addition of ¹⁵N-labeled nitrate to inflow water. DNRA is an important process in some Texas coastal systems and its importance increases with salinity. DNRA is also a significant mechanism for retaining nitrogen in Florida Bay. DNRA rates related to sediment oxygen consumption rates in that region, regardless of season (August 2004 vs. January 2005), whereas denitrification rates were low in summer. DNRA thus provides an explanation for the high NH₄⁺:NO₃^- and high NH₄⁺:PO₄^3- ratios, often observed in Florida Bay. It may be an important mechanism affecting N and O₂ dynamics in marine “low-oxygen dead zones,” as occur in the northern Gulf of Mexico and other regions, but is less important in comparable freshwater systems such as Lake Erie.

Wednesday
August 2

Title: "Why there are beaches (the influence of wave boundary layers on shoreward sand transport)"

Speaker: Dr. Stephen Henderson, Postdoctoral Associate, Scripps Institution of Oceanography Center for Coastal Studies
University of California, San Diego

Abstract:
This seminar will discuss processes responsible for the shoreward sand transport that creates beaches. I will also briefly outline my research on waves and currents near the shore.

Orthodox energetics-based sediment transport models, which do not accurately resolve water flows near the seabed, sometimes fail to predict shoreward transport of sand on natural beaches. To study the near-bed flows that carry sand shoreward, I developed an eddy-diffusive numerical boundary layer model of water and suspended sediment motion. This model was combined with velocities measured about 0.5 m above the bed to predict the erosion and accretion of a natural beach. After tuning of a single free parameter, the model successfully predicted most of the erosion and accretion observed over several months. Waves carried shoreward momentum into the near-bed region, contributing to shoreward sediment transport. Shoreward sediment transport was further encouraged by the Stokes drift. Together, wave-generated momentum fluxes and the Stokes drift substantially increased shoreward sand transport, and were essential to successful predictions of erosion and accretion.

Wednesday
July 12

Speaker: Anastasija Zaiko, Ph.D. student,
Coastal Research and Planning Institute
Klaipeda University, Klaipeda, Lithuania

Abstract:
The Curonian Lagoon, a large shallow (mean depth 3.8 m) and nearly freshwater body situated in the south-eastern part of the Baltic Sea, was invaded by several Ponto-Caspian Species in the beginning of the 19th century after the water link between the Nemunas and Dnepr rivers was established. The invasion of the zebra mussel Dreissena polymorpha had the most pronounced effect on the Curonian Lagoon ecosystem. The impact can be traced at different levels: from a local bottom community to the biogeochemical cycle of the whole ecosystem.

The zebra mussel, as a main habitat forming animal species, to a great extent determines the taxonomic and functional guild structure of the local bottom communities. Its community covers about ¼ of the lagoon’s bottom. The area covered by its shell deposits is even larger. The highest macrozoobenthos diversity is found there. There is also a gradient in species composition detected moving from bare sediments through shell deposits and towards the living zebra mussel community.

An invasibility analysis of different habitats within the Lithuanian offshore and coastal waters indicated that the most invaded habitats are those modified by zebra mussel or its shell deposits.

Another aspect of zebra mussel effect – its impact on the material flow at the ecosystem scale. The D. polymorpha clearance and biodeposition rates are interpolated to the entire Lagoon ecosystem using experimental and modeling approach.

Thursday
June 22

Speaker: Ken H. Brink, Department of Physical Oceanography, Woods Hole Oceanographic Institution

Abstract:
CICOR (Cooperative Institute for Climate and Ocean Research) is, since 2001, the primary channel for cooperation between NOAA and the Woods Hole Oceanographic Institution (WHOI). Its goal is to develop and execute research relevant to NOAA needs, with a focus on 1) the ocean’s role in climate and climate variability, 2) the coastal ocean and near-shore processes, and 3) marine ecosystem processes. To date, CICOR has been especially effective with regard to the first and third themes. Yet, Woods Hole has an extremely active program in coastal ocean research, so there is considerable potential for enhanced cooperation, both in terms of cooperation in ongoing programs and of strategic planning to meet longer-term objectives. Examples of WHOI coastal ocean capabilities include shoreline change, near-shore processes, numerical modeling and theory, process-oriented observations, and developing long-term coastal ocean observing systems.

Monday
May 22

Title: "Food web structure and the importance of species interactions in a Venezuelan stream"

Speaker: Bryon A. Daley, University of Michigan School of Natural Resources and Environment

Abstract:
Interactions among species can have important impacts on ecological processes, ranging from individual behavior to ecosystem function. However, there is a growing recognition that the importance of species interactions is context-dependent; organisms that are functionally important under one set of abiotic and biotic conditions may have little or no effect under another. Consequently, our ability to predict how changes in biodiversity will influence ecological processes depends on identifying factors underlying the importance of species interactions across space and taxa. Using a combination of descriptive and experimental approaches, I examined the direct and indirect effects of species interactions across riffle and run habitats in an Andean piedmont stream. In addition, I experimentally contrasted the relative effects of an herbivorous fish and a substantially smaller invertebrate grazer on algal and invertebrate assemblages. Specifically, I tested the prediction that large-bodied herbivores have a greater impact on algal and invertebrate assemblages compared to their smaller counterparts.

The direct and indirect effects of species interactions varied across habitats. Both the sedentary, invertebrate herbivore, Petrophila sp. (Pyralidae), and the grazing armored catfish, Chaetostoma milesi (Loricariidae), significantly reduced algal biomass in riffles, but had no effect on algal biomass in runs. This variation was likely due to discrepancies in invertebrate settlement rates and differences in the composition of fish assemblages across habitats, as well as the different environmental conditions in the two habitats (e.g., water depth, current velocity, and dissolved oxygen concentration). Surprisingly, results of the second experiment did not support the prediction that large-bodied herbivores have a greater impact on algal and invertebrate assemblages relative to small-bodied herbivores. The effect of the invertebrate herbivore, Petrophila sp., on algal and invertebrate assemblages was equal to the effects of the grazing catfish, Chaetostoma milesi. In addition, Petrophila had a significantly greater per biomass effect on algal biomass compared to Chaetostoma.

In an effort to reduce the impact of biodiversity loss on community and ecosystem processes, ecologists have stressed the importance of identifying strong interactors. Some authors have proposed that conservation efforts should focus on non-redundant species that perform essential ecosystem functions. Results from my experiments suggest that species interactions in a diverse stream system vary across habitats, and that an understanding of the biotic and abiotic contexts is important in identifying strong interactors. Furthermore, a full understanding of functional redundancy in natural systems may require an examination of a wider range of taxonomic and morphologically different species than is generally recognized.

Thursday
May 18

Title: "Nonlethal effect of an invasive invertebrate predator, Bythotrephes, on the population growth rate of zooplankton prey in Lakes Michigan and Erie "

Speaker: Dr. Scott Peacor, Ecological and Ecosystem Modeler, NOAA/GLERL
Assistant Professor, Department of Fisheries & Wildlife, Michigan State University

Abstract:
We evaluated the nonlethal effects (i.e. due to induced phenotypic modifications) relative to lethal effects (i.e. through consumption) of an invasive invertebrate predator, Bythotrephes longimanus, on zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both systems indicated that prey species, Daphnia mendotae, Daphnia retrocurva, and Bosmina longirostris inhabited deeper portions of the water column as Bythotrephes biomass increased, demonstrating the generality of this response. This induced behavioral response is supported by laboratory experiments. Whereas the induced migration reduces predation risk, it comes at the cost of reduced birth rate, due to inhabiting regions of lower temperature. We estimated the nonlethal (i.e., resulting from reduced birth rate) and lethal (i.e., consumptive) effects of Bythotrephes on D. mendotae and B. longirostris. These estimates used diel field survey data of the vertical gradient of zooplankton prey density, Bythotrephes density, light intensity, and temperature, with growth and predation rate models based on laboratory studies. Results indicate that nonlethal effects play a substantial role in the net effect of Bythotrephes on prey population growth rate, with nonlethal effects on the same order of magnitude or greater (up to 10 fold) than lethal effects. This study therefore demonstrates that nonlethal effects can contribute substantially to net predator effects on prey at the population level in an uncontrolled field environment. Results of a simple model are presented that predict this result. Our results further indicate that invasive species can have strong nonlethal, behaviorally-based effects, despite short evolutionary coexistence.

Wednesday
May 3

This was one of the Ocean and Human Health special topic seminars.

Title: "A quantitative microbial risk assessment framework for the Great Lakes."

Speaker: Dr. Joan Rose, Michigan State University, Environmental Microbiology Laboratory

Abstract:
The conventional National Academy of Sciences approach (4 steps Hazard Identification, dose-response, exposure assessment and risk characterization) can be used in the Great Lakes to examine health risks and environmental monitoring data. Prevention and control of infectious diseases requires an understanding of the ways bacteria, viruses and parasites are spread. Environmental transmissible agents such as waterborne pathogens are particularly a challenge due to the emergence of viruses and parasites which are resistant to conventional means of water and wastewater treatment. Knowledge of the transmission systems [including transport and survival] of many potential agents is incomplete; thus we need to greatly enhance the ability to effectively predict and anticipate the extent of an epidemic following a water contamination event, and develop management strategies for control. Quantitative microbial risk assessment (QMRA) is now a field which has developed over the last decade and is used to address both probability of infection and community risks. The new challenges facing the development of a strategy for achieving community goals of for water quality and water safety require that greater specificity regarding the infectious agent is addressed and that better assessment of exposure is undertaken. Methodologies associated with sampling [e.g. air, water, and surfaces] will need to take into account the level and extent of exposure and be able to interpret this in regard to health outcomes. Future advances will focus on models of the agent and its transmission as well as analytical methods using environmental and epidemiological data. The use of QMRA can be used to set priorities for improving the safety of water and for setting relevant public policy. Many examples of QMRA applications are available from defining drinking water treatment to the blending rule for sewage to protection of beaches. The new tools, techniques and models can be used to modify the risk assessment strategy for addressing microbial contaminants in the Great Lakes.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/rose/20060503.wmv
Pdf:
ftp://ftp.glerl.noaa.gov/webcast/2006/rose/20060503.pdf
PowerPoint:
ftp://ftp.glerl.noaa.gov/webcast/2006/rose/20060503.ppt

Title: "Studying long-term ice changes."

Speaker: Dr. Igor Appel, Raytheon Corporation, Washington, D.C.

Wednesday
April 19

Dr. Wanli Wu, Climate and Global Dynamics Division
National Center for Atmospheric Research

Abstract:
Understanding regional climatic contribution and its response to global change has been in the interest of both the scientific community and society in general. The Arctic has been recognized as one of most sensitive areas on the Earth to global change. The Arctic climate system involves complex interactions between the atmospheric, terrestrial, oceanic, and sea ice components. By combining modeling with observations, climate variability (spatial and temporal) in the northern high latitudes is presented. The modeling includes regional climate model (RCM) and global climate model (GCM) simulations. Multiple observational datasets (from global reanalysis to satellite data) are used 1) to qualify uncertainty in the observations; 2) to validate climate models; and 3) to document the regional climate variability. The climatological mean state, its trend along with their seasonal cycle, interannual variability are analyzed. Though deficiencies in observational datasets and biases between models and observations, the modeling and observations are generally in good agreement on recent changes in the Arctic system: decreasing sea level pressure, increasing surface air temperature, and downward trend in sea ice extent. Besides annual trend, monthly trends of the regional climate are estimated. The trends show strong seasonality: large in the wintertime while small (or opposite sign) in the summertime. Similar seasonal variation can also be seen in the interannual variability of the regional climate. Additionally, the regional climate model not only reproduces many large-scale features as in the observations, but also develops mesoscale characteristics that are missed in global reanalysis and global models. The added regional details by RCMs are crucial for applications such as regional climate impact assessments and water resource evaluations.

Wednesday
April 12

Title: "Condition and diet of lake whitefish in Lakes Michigan and Huron"

Speaker: Steve Pothoven, Fishery Biologist, Lake Michigan Field Station, NOAA/GLERL

Abstract:
Fishery managers and commercial fishermen have expressed concern about recent declines in lake whitefish body condition in the Great Lakes. We evaluated the diets of lake whitefish throughout Lake Michigan during 1998-2004 and Lake Huron during 2002-04 to determine what prey types are currently eaten following dreissenid invasions and Diporeia declines. Results from both lakes confirm that Diporeia are a major prey source when available. In the absence of Diporeia, lake whitefish tend to eat more Mysis, Chironomidae, zooplankton, or dreissenid mussels, depending on geographic location and fish size. These prey either contain little energy or are less abundant than Diporeia were historically. Based on data from Lake Huron, the type of prey eaten affected the food and energy intake differently for different size classes of lake whitefish. Food weight in juvenile lake whitefish stomachs did not differ across prey groups, but energy in stomachs was highest for fish that ate mainly non-mollusc macroinvertebrates. For large lake whitefish, there was no difference in food weight or energy in stomachs for different prey groups. The size of benthic prey (Diporeia, Chironomidae, and Dreissena spp.) eaten increased with fish size and influenced the energetic content of prey for different size groups of fish. Energy density and body condition of lake whitefish was higher in Lake Michigan than Lake Huron. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

Video archive available:
ftp://ftp.glerl.noaa.gov/webcast/2006/pothoven-intro/20060412.wmv (intro)
ftp://ftp.glerl.noaa.gov/webcast/2006/pothoven/20060412.wmv (seminar)
PowerPoint available:
ftp://ftp.glerl.noaa.gov/webcast/2006/pothoven/20060412.pdf

Monday
April 3

UofM SNRE, Room 1040

This was one of the Ocean and Human Health special topic seminars.

Title: "From global climate change to local land use practices: are we increasing the risk of disease emergence?"

Speaker: Dr. Jonathan Patz, Associate Professor of Environmental Studies and Population Health Sciences, University of Wisconsin-Madison

Abstract:
The World Health Organization concluded that the climatic changes that have occurred since the mid 1970s could already be causing over 150,000 deaths per year, mainly in developing countries. The human health risk resulting from climate change is expected to more than double by the year 2030. Many health outcomes and diseases are sensitive to climate, including: heat-related mortality or morbidity; air pollution-related illnesses; infectious diseases, particularly those indirected transmitted via water (waterborne) and by insect or rodent vectors (vectorborne); and refugee health type issues linked to forced population migration. Yet, changing landscapes can significantly affect local weather more acutely than longterm climate change. Land cover change can influence micro-climatic conditions including temperature, evapotranspiration, and surface runoff, key to determinants to the emergence of many infectious diseases. These separate and synergistic processes (climate and land use change) will be presented.

Friday
March 17

This was one of the Ocean and Human Health special topic seminars.

Title: "Beach closings panel discussion"

Speakers: Dr. Richard Whitman, USGS
Adrienne Nemura, Limno-Tech, Ann Arbor
Dr. Charles Tseng, Purdue University

Abstract:
An hour long scientific discussion with three renowned experts of beach closures. This is a great opportunity to learn about the many aspects that determine and affect the reasons why our beaches are closed. From watershed modeling to genetic mapping, there is truly a lot to be learned about the complexity of why our beaches are closed.

Thursday
March 9

Title: "Sculpin prey selection dynamics: patterns and processes"

Speaker: Daryl Hondorp, CILER, University of Michigan graduate student

Abstract:
Many characteristics of benthic fish and their prey differ from the planktivore-zooplankton model on which fish foraging theory is based, but few studies have examined prey selection in benthic fishes. In this study, species and size selection of macroinvertebrate prey was described for the benthic fish Cottus cognatus and Myoxocephalus thompsonii from southeast Lake Michigan. Both field and laboratory studies were employed to investigate the effects of prey species composition, abundance and behavior on prey selection by these fish. Results were consistent with the hypothesis that prey selection in C. cognatus and M. thompsonii is mainly a passive process wherein all prey are equally suitable but differ in vulnerability. Thus, more vulnerable prey types are preferentially consumed when predators feed opportunistically. Study results suggested that prey vulnerability for these fish was a function of prey micro-habitat use, motility, and evasiveness which influenced predator-prey encounter rates and predator capture success. Chironomids (Order: Diptera; Family: Chironomidae) were an example of a vulnerable prey type due to their spatial overlap with benthic fish and limited motility, and were preferentially consumed by C. cognatus. Mysis relicta was considerably less vulnerable to fish predation as a result of its vertical-migrating behavior and its ability to escape from attacks by benthic predators. Prey vulnerability was mostly unaffected by prey density or fish size, although C. cognatus and M. thomposonii may differ in their ability to detect and capture certain prey types. Active predator choice could not be ruled out as a factor influencing the prey selection of these fish, but results from this and other studies suggest that much of the variation in prey selection by benthic fish can be explained solely by passive mechanisms.

PowerPoint available:
ftp://ftp.glerl.noaa.gov/webcast/2006/hondorp/20060309.ppt

Friday
February 24

This was one of the Ocean and Human Health special topic seminars.

Title: "A day at the beach: priceless?"

Speaker: Sabina Shaikh, University of Chicago, RCF Economic Consulting

Abstract:
Using the results from a survey of 1500 Chicago beach goers in the summer of 2004, this study provides information on beach use, including a description of visitors and their preferences for beach and lakefront amenities.

An economic model of the demand for beach trips is used to calculate of the value of spending a day at the beach, the seasonal value for Chicago beaches, and the lost value associated with swim bans. Additionally, non-market valuation is employed to compute beachgoers willingness to pay to reduce swim bans by 50 percent.

The estimated per-person value of a day at the beach is $35, which is higher than estimates for other beaches in the U.S. the value for a day at a Lake Erie beach. The total seasonal value for beach goers in 2004 is just over $800 million, and over $1 billion in other years with higher attendance.

The lost value to individuals who would not visit the beach in the case of a swim ban totals over $17 million for the season, and is likely much higher since additional sources of lost value exist.

A comparison of valuation techniques shows the various sources of value for Chicago beaches, including use value from swimming, non-use value from knowing the beaches and water are clean, and the values associated with preserving the beaches for future generations.

PowerPoint available:
ftp://ftp.glerl.noaa.gov/webcast/2006/shaikh/20060224.ppt

Thursday
February 2

UofM SNRE Room 1040

This was one of the Ocean and Human Health special topic seminars.

Title: "Spatially distributed surface—subsurface watershed hydrology model of water and materials runoff"

Speaker: Dr. Thomas Croley, Research Hydrologist, NOAA/GLERL

Abstract:
Prediction of various ecological system variables or consequences (such as beach closings), as well as effective management of pollution at the watershed scale, require estimation of both point and non-point source material transport through a watershed by hydrological processes. The Great Lakes Environmental Research Laboratory and Western Michigan University are developing an integrated, spatially distributed, physically-based water quality model to evaluate both agricultural non-point source loadings from soil erosion, animal manure, and pesticides, and point source loadings at the watershed level. We have reviewed available water quality models and are augmenting an existing physically based integrated surface/subsurface hydrology model. It is a two-dimensional, spatially-distributed accounting of moisture in several layers (zones) for every “cell” (1 square kilometer) of a watershed. We previously modified the model to allow flow routing between adjacent cells surface zones, upper soil zones, lower soil zones, and groundwater zones. We applied it on a daily basis to several new Great Lakes watersheds this year. We are now expanding it by adding material transport capabilities to it to include movement of other materials besides water. We have demonstrated its material transport capabilities on the several watersheds. We are also modifying the model from a daily time step to an hourly. We are now gathering information on pollutants in Saginaw Bay watersheds to apply the model to simulate the movement of various materials into the bay, producing estimates useful to ecological system forecasters.

Friday
January 27

This was one of the Ocean and Human Health special topic seminars.

Title: "Update on a national preliminary algal toxin occurance study that monitored source and distribution waters"

Speaker: Judy A. Westrick, Lake Superior State University, Department of Chemistry and Environmental Sciences, Sault Sainte Marie, MI

Abstract:
Cyanobacterial blooms occur worldwide in marine, brackish, and fresh waters. At least one-third of these genera are capable of producing toxins. In 1998 and 2005, fresh water algal toxins were added to the Contaminant Candidate List (CCL) by the United States Environmental Protection Agency (USEPA). Shortly after the 1998 announcement, a priority list was released that included five hepatotoxins, microcystin-LR, -RR, -LA, -YR, and cyclindrospermopsin, and the neurotoxin anatoxin-a. Current World Health Organization (WHO) monitoring guidelines incorporate a sequence of alert levels based on algal cell counts and/or taste and odor production that were established in 1993. These alert levels start at cell counts of 2000 units/mL and increase the frequency of monitoring. We describe a preliminary study funded by the USEPA to evaluate the prevalence of the algal toxin microcystin in drinking water supplies. An Enzyme-Linked Immunosorbant Assay (ELISA) was used to screen the source and distribution water samples for microcystin. The ELISA kit has a range limit of 0.05 ppb to 0.83 ppb microcystin. Total and toxin-producing algal counts were conducted on weekly source and distribution water samples from utilities located in five US states. Four of the five utilities experienced algal blooms in their source water. All of these conventional plants effectively removed the algae and all distribution water samples showed microcystin levels below the detection limit of 0.05 ppb. Four of the utilities source water did show detectable levels of microcystin within the range limits of the kit. Selected source water samples were analyzed by high pressure liquid chromatography (HPLC). We describe this HPLC method capable of quantifying intracellular microcystin toxin variants, as well as cylindrospermopsin and anatoxin-a, and compare it to the ELISA. The WHO algal toxin monitoring framework and monitoring cost was evaluated against for different analytical methods and scenarios.

Friday
January 13

UofM SPH I, Aud

This was one of the Ocean and Human Health special topic seminars.

Title: "Health implications of biofilms"

Speaker: Anne Camper, Associate Dean for Research and Graduate Eduation, College of Engineering, Montana State U, Bozeman

Abstract:
Biofilms in drinking water systems can impact health in at least two ways. First, it is known that opportunistic pathogens can be part of the indigenous microbial biofilm populations found on distribution system and premise plumbing surfaces. When released from the biofilm and ingested/inhaled by a susceptible host, disease may occur. Organisms known to be associated with drinking water systems and disease include Legionella and Mycobacteria, and there is some evidence that Pseudomonas aeruginosa may also be in this category. Even less well understood is the interaction of other pathogens with indigenous drinking water biofilms. Questions include: How well are pathogens retained? What is their physiology? Are they rendered less susceptible to disinfection? Is their infectivity altered? Can they be released in sufficient numbers to cause disease? Although there are no answers at present to most of these questions, research is underway to provide initial insight. Our work has been focused on the manner in which the pathogenic bacteria Escherichia coli O157:H7 and Salmonella typhimurium are trapped and retained by biofilms. Inherent in these studies is the need to have good methods for pathogen detection in environmental samples. Recent advances in real-time PCR detection and the use of novel live/dead methods will be discussed. Results of experiments demonstrating the retention of pathogens in biofilms will also be presented.

Thursday
January 12

Speaker: Alan E. Wilson, Georgia Institute of Technology, Biology Department

Abstract:
Interactions between herbivores and bloom-forming cyanobacteria play an important role in mediating the responses of freshwater phytoplankton assemblages to nutrient enrichment and top-down manipulation. Consequently, numerous observations have been made over the past four decades aimed at understanding the mechanisms mediating these interactions, namely cyanobacterial morphology or toxic secondary metabolites. Results from laboratory and field experiments will be presented that show how the morphology or secondary metabolites of the cyanobacterium, Microcystis aeruginosa, influence the feeding preferences of the invasive bivalve, Dreissena polymorpha, or the fitness of the common lake-dwelling zooplankter, Daphnia pulicaria. Interesting responses across different Microcystis and Daphnia strains isolated from Michigan lakes will be highlighted.