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Presentation Abstracts
Title: Impacts of Nomadic Pastoralism and Climate Change on Six Lake Hovsgol Watersheds, Northern Mongolia
Author:
Clyde E. Goulden, PhD
Director, Institute for Mongolian
Biodiversity and Ecological Studies
Academy of Natural Sciences, Philadelphia
and
International Consultant Hovsgol GEF Project
Mongolian Academy of Sciences
www.hovsgolecology.org
Abstract:Northern Boreal regions of the World are experiencing greater climate warming than more temperate regions such as most of the United States. Northern Mongolia at 51° N has warmed almost 2° C over the last 40 years. In this region, winters have become shorter and warmer and summers are longer. As a result, in the absence of increased summer precipitation, soil moisture, critical to plant growth in this semi-arid landscape receiving on average only 12 inches of rain a year, is decreasing. Northern Mongolia also represents the southern-most extension of continuous permafrost in Asia, and permafrost is undergoing thaw. Hydrologic cycles, the region's forests and steppe grassland plants are presently being affected. These are all changes that may impact temperate regions in the not too distant future.
The Hovsgol GEF (Global Environment Facility) Project has been studying climate change impacts on six watersheds entering Lake Hovsgol along the eastern shore of the lake, and the impact of nomads and the grazing of their livestock in the region. In addition, the Project has trained 23 young Mongolian scientists in modern methods of environmental impact assessment and provided English lessons with the help of the U.S. Peace Corps. The training has included scientific workshops and exchange visits with international scientists from the U.S. and other countries.
Nomad families have still not adjusted to these changes, though they are aware that the steppe plants are not growing well and they complain that their animals are not doing well. However, most of the nomads are more accustomed to allowing a pasture to be overgrazed, and then moving on to fresh pasture areas, but the families of the eastern Hovsgol shore are unable to move, they are in a "corner". They must adapt their grazing practices to present and future conditions and develop more sustainable grazing methods for the pastures. If the steppe cannot become more sustainable by improved practices, some herders will very likely need to leave the region, but there are few places for them to go so they may need to give up herding. But nomadic pastoralism has been the social safety net for large areas of Central Asia.
Title: Effects of the Discharge of Spent Cooling Water from Lake Ontario on Onondaga Lake: A Preliminary Analysis
Authors:
Steven W. Effler, Emmet M. Owens, David A. Matthews, and Susan M. O'Donnell
Upstate Freshwater Institute, Syracuse, NY
James M. Hassett
SUNY College of Environmental Science and Forestry, Syracuse, NY
Abstract:Limnological, water quality and management issues for a proposed Lake Source Cooling (LSC) facility discharge from oligotrophic Lake Ontario to polluted eutrophic Onondaga Lake are considered. The analysis draws upon multiple monitoring data sets, including from the two lakes, a proximate existing LSC facility operated by Cornell University, and a local National Weather Service monitoring site. A tested dynamic mechanistic model is used to support the analysis through simulations of the effects of the proposed LSC discharge on Onondaga Lake's thermal stratification/transport regime, hypolimnetic dissolved oxygen (DO) and epilimnetic total phosphorus concentrations (TPe). Density calculations with an equation of state indicate the spent cooling water would tend to enter the lake's metalimnetic depths, in the absence of artificial mixing associated with a diffuser. Potential benefits of the discharge are associated with low nutrient and high DO concentrations of the Lake Ontario water. The model is applied to evaluate an array of LSC discharge depth and volume scenarios, including a hypolimnetic diffuser. Simulations indicate that discharge of LSC effluent to the metalimnion or hypolimnion would not significantly improve dissolved oxygen conditions. However, several alternatives are projected to improve phosphorus levels in the productive upper waters, with the most effective being the discharge of mixed LSC and Metro effluent to the metalimnion. The predicted effects of a LSC discharge are considered in the context of current rehabilitation efforts for the lake.
Title: Changes in the Littoral Aquatic Plant Community of Onondaga Lake from 1991 to 2006
Authors:
John D. Madsen
Mississippi State University, MS
Abstract:Aquatic plants are an important component to the littoral zone ecosystem; they provide food to aquatic organisms, habitat to fish, refugia to young-of-the-year fish, and stabilize sediment. As with other biological communities within lakes, aquatic plant communities will change as the result of environmental degradation and alteration. Whole-lake aquatic plant surveys were performed in Onondaga Lake during the summers of 1991, 2000, 2002, 2004, 2005, and 2006. In 1991, forty 100m transects were deployed at stratified-random intervals along the shoreline, and the presence or absence of rooted plants recorded in 0.1 m-2 quadrats located at 1 m intervals along each transect. For 2000 and after, a point-intercept technique was utilized in which the presence or absence of plants at predetermined points was utilized. A GPS unit was utilized to navigate to the predetermined location. Presence of plants was determined using a plant rake, or visually in shallow water. All plant data were analyzed based on the frequency of occurrence of plants in the littoral zone, defined for this purpose as water depths less than or equal to 5m. In addition to frequency of each species, the total cover of plants of any species, average number of species per point or quadrat, and species richness per year were calculated. In 1991, only 13% of all quadrats had a plant present. In contrast, during the period 2000 to 2006 the percent cover of plants at littoral points ranged from 70.7% to 83.3%. The average number of plants per quadrat in 1991 was 0.125, while in 2005 the average number of species per littoral zone point was 2.63. The total number of species observed during the survey in 1991 was 5, while the total species list for the 2006 survey was 16. Individual species distributions also changed radically during this period, including Ceratophyllum demersum (from 0.3% in 1991 to 34.1% in 2006), Elodea canadensis (from not found in 1991 to 69% in 2005), Heteranthera dubia (from 2% in 1991 to 44.6% in 2000), Myriophyllum spicatum (from 0.06% in 1991 to 53.5% in 2005), Potamogeton crispus (from 0.3 in 1991 to 41.1% in 2004), Potamogeton foliosus (from not found in 1991 to 41.3% in 2006), and Stuckenia pectinata (from 11% in 1991 to 45.8% in 2000). While the exact causes of this dramatic change in littoral vegetation cannot be determined from observation alone, previous experimental research substantiates that the simultaneous change in several environmental parameters may have allowed an increase in plant growth, including increased water clarity, decreased salinity, and decreased calcium loading rates.
Title: Changes in Primary Production of Onondaga Lake in Response to Reductions in Phosphorus Loading from Metro
Authors:
Adam J.P. Effler and James Hassett
SUNY College of Environmental Science and Forestry, Syracuse, NY.
Rakesh K. Gelda and Steven W. Effler
Upstate Freshwater Institute, Syracuse, NY
Stephen D. Field
Compliance Consultants, Baton Rouge, LA
Abstract: Primary production is a central feature of the metabolism of surface waters, and a principal regulator of important aspects of water quality such as the concentration of algae, water clarity, and hypolimnetic oxygen resources. Systems where both major reductions in nutrient loading have been achieved and historic measurements of primary production exist, such as Onondaga Lake, offer rare opportunities to assess the character of metabolic response as well as the efficacy of related management actions. Results of primary production and community respiration experiments conducted in Onondaga Lake in 2005 are presented and compared to earlier observations reported for 1978, 2000/2001, and 2002. The experiment protocols adopted in the 2005 study tracked those used in 1978 to enhance comparisons with that year, which had the highest phosphorus (P) loading rate and most complete set of primary production and community respiration measurements. Accordingly, the 2005 study included measurements of dissolved oxygen initially and in light and dark bottles that had been incubated in situ for 6 daytime hours, at five depths extending from the surface through the photic zone. Sixty-eight experiments were conducted at the south deep site over the April-October interval. The time course of reductions in P (the limiting nutrient) loading from the Metropolitan Syracuse Wastewater Treatment Plant (Metro), that included a 14 fold reduction from 1978 to 2005 is reviewed. Seasonal and vertical patterns of volumetric primary production [gross (Pg/v) and net (Pn/v)] and community respiration (Rc/v), and the corresponding dynamics of areal values (e.g., Pg/a, Rc/a), are characterized for 2005. The average near-surface volumetric gross primary production (Pg/v) in 2005 was 0.24 gO2/m3/hr; the average areal gross primary production (Pg/a) in 2005 was 4.47 gO2/m2/d. The average near surface Pg/v in 2005 was 4.25 fold lower than in 1978. However, the decrease in Pg/a, the best measure of overall primary production, from 1978 was not as great (2.76 fold lower) because of a partially compensating deepening of the depth(s) of the water column that can support photosynthesis.
Title: Characteristics of Light Absorption in Onondaga Lake, NY
Authors:
MaryGail Perkins, Christopher Strait, Lingsen Zhang, David M. O'Donnell and Steven W. Effler
Upstate Freshwater Institute, Syracuse, NY
Abstract: The light absorption coefficient (a, m-1) quantifies the magnitude of light absorption, one of the two light attenuating processes in water. Light absorbing constituents are important in regulating optical features of water quality, including the spectral composition of emergent light flux, the signal available for remote sensing. The magnitudes of a (minus contribution of water itself) and its primary components, colored dissolved organic matter (CDOM, or gelbstoff; aCDOM), phytoplankton (aphyto), and non-phytoplankton particulates (anon/phyto), were determined on a weekly basis, for the near surface waters of Onondaga Lake, NY, in 2006. Components of a were determined through laboratory spectrophotometric protocols on filtrates (CDOM) and filters (phytoplankton and non-phytoplankton particulates, before and after bleaching). A limited number of in situ measurements of a were made with a spectral profiler (WetLabs ac-s) in the field, and compared to the summation of components (dissolved and particulate) determined in the lab. Temporal variations were observed for all components in the lake. Absorption due to CDOM accounted for 26 – 54% of the total absorption. On average, CDOM and total particulate components contributed approximately equally to the total absorption. The range of values of a, and its components, make this system a good candidate to test and apply remote sensing approaches for monitoring inland water quality.
Title: Impacts of Nitrate on Hypolimnetic Processes in Onondaga Lake: 1. Control of Redox Status and Sulfide Accumulation
Authors:
David A. Matthews and Steven W. Effler,
Upstate Freshwater Institute, Syracuse, NY
Charles T. Driscoll
Syracuse University, Syracuse, NY
Abstract: The impact of nitrate on the oxidation-reduction (redox) status of Onondaga Lake is assessed from weekly, vertically detailed water column measurements of key electron acceptors (O2 and NO3-) and reduced byproducts of anaerobic decomposition (HS-and CH4). Spatial and temporal patterns of these constituents are considered within the context of a conceptual model of redox processes in aquatic sediments. The commencement of year-round nitrification at a domestic wastewater treatment facility, which contributes approximately 20% of the annual inflow to the lake, caused a nearly two-fold increase in NO3- concentrations at spring turnover. The larger pool of NO3- present in the hypolimnion at the onset of summer thermal stratification resulted in a prolonged interval of NO3- reduction and delayed the onset of HS- accumulation by more than 60 days compared to years before improved nitrification treatment. In the presence of NO3-, redox potentials were poised between 100 and 250 mV in the anoxic hypolimnion, a level favorable for denitrification and higher than the -50 mV required for sulfate reduction. The observed sequence of O2 depletion followed by NO3- depletion and HS- accumulation is consistent with thermodynamic calculations of the energy yields of redox processes. The timing of CH4 accumulations in the hypolimnion indicates the operation of methanogenesis at depth within the sediments. Accumulation of HS- in the hypolimnion was limited to depths where NO3- was absent, suggesting the possibility of an alternate NO3- reduction pathway, dissimilatory nitrate reduction to ammonia (DNRA) coupled to sulfide oxidation. The relative importance and potential water quality impacts of DNRA are addressed. Potential effects of the observed decrease in sulfate reduction are discussed, including decreased production of methylmercury (CH3Hg+) during summer stratification and reduced oxygen depletion during fall turnover.
Title: Impacts of Nitrate on Hypolimnetic Processes in Onondaga Lake: 2. Preliminary Evidence for Reductions in Methyl Mercury Production
Authors:
Svetoslava Todorova, Charles Driscoll
Syracuse University, Syracuse, NY
Susan O'Donnell, David Matthews, and Steven Effler
Upstate Freshwater Institute, Syracuse, NY
Abstract: Mercury contamination has persisted in Onondaga Lake for the last five decades largely as a result of industrial discharge that was terminated in 1986. Sediment core data reveal a marked decrease in mercury loading to the lake since 1970s. However, Onondaga Lake continues to be a source of monomethyl mercury. Monomethyl mercury (MMHg), a known neurotoxin, forms under anoxic conditions mainly by sulfate reducing bacteria and has the potential to bioaccumulate through the food web. Mercury concentrations in the lake's fish have continued to exceed the EPA limit of 0.3 ppm for 30 years.
Substantial efforts have been undertaken to select the proper remedial actions to mitigate Hg concentrations in the lake and its fish habitat. Dredging contaminated sediments and aeration of the hypolimnion are among the proposed methods. In 2004, a new biological aerated filter system was installed at the Syracuse Metropolitan Sewage Treatment Plant (METRO) to reduce the discharge of ammonia to the lake. This new system promotes efficient nitrification of ammonia and resulted in a marked increase in nitrate inputs to the lake.
The current study focused on the implications of increased nitrate inputs on mercury dynamic in the lake. Rapid accumulation of MMHg in hypolimnion was observed only after nitrate was depleted. Results to date revealed no significant change in the total and monomethyl mercury concentrations observed in the lake water column as compared to a reference year. However, the onset of MMHg production, though, was substantially delayed resulting in overall decrease in the period the water column pool of methyl mercury was elevated. Nitrate addition as a potential remediation alternative for the inhibition of MMHg production is currently under investigation. Temporal variations in MMHg concentrations in the hypolimnion appear to be influenced by local meteorological conditions. The effect of wind dynamics on Hg supply to the epilimnion is discussed.
Title: Nitrate and Bisulfide Patterns in Onondaga Lake, NY, and Adjoining Waters by ISUS Following Implementation of Nitrification Treatment at Metro
Authors:
Anthony R. Prestigiacomo, Steven W. Effler and David A. Matthews
Upstate Freshwater Institute, Syracuse, NY
Abstract: Spatial and temporal patterns of nitrate (NO3-) and bisulfide (HS-) are documented in mercury polluted, culturally eutrophic, Onondaga Lake, NY, following implementation of year-round nitrification treatment at the Metropolitan Syracuse Wastewater Treatment Plant (Metro). The treatment upgrade is described in the context of the degraded state of the lake, ongoing rehabilitation programs for domestic wastes and industrial contamination, and the significance of in-lake patterns of NO3- and HS-. Lake measurements of NO3- and HS- were made in situ with a high resolution rapid profiling ultraviolet spectrophotometer (ISUS), and validated by standard laboratory wet chemistry analyses. A nearly two-fold increase in epilimnetic NO3- concentrations, and prolonged presence of NO3- and delay of the onset of HS- accumulations in the hypolimnion by about two months, are demonstrated. Detailed vertical patterns resolved within the anoxic hypolimnion depict first the operation of the thermodynamically favored NO3- reduction process(es) and subsequently sulfate (SO42-) reduction, and the localization of these processes in the lake's sediments. Variations in the effective depth of entry of the Metro discharge into the lake's water column from the surface waters to mid- (or metalimnetic) depths are demonstrated. Two- and three-dimensional patterns of NO3- formed from ISUS profiles collected at multiple sites over brief intervals on multiple occasions depict substantial spatial and temporal structure mediated primarily by variations in hydrodynamic processes. Ongoing ISUS measurements will: (1) document forthcoming systematic changes in the lake from continuing rehabilitation efforts, (2) track the transport and fate of the Metro discharge, and (3) provide monitoring capabilities to guide contemplated supplemental additions of NO3- to the hypolimnion to block SO42- reduction and thereby mobilization of methyl mercury from the lake's sediments.
Title: Mercury Sequestration via Nitrate Addition: A Modeling Analysis of Management Alternatives
Authors:
Martin T. Auer, and Gilbert N. Lewis
Michigan Technological University, Houghton, Michigan
Steven C. Chapra
Tufts University, Medford, Massachusetts
Abstract:Decades of industrial discharges have left the bottom sediments of Onondaga Lake contaminated with mercury. A major objective of plans to restore water quality conditions in the lake is to sequester the mercury in those sediments, separating it from the food web. Mercury methylation, i.e. production of the bioavailable form of the contaminant, has been showed to be closely linked to microbial sulfate reduction. Thus, it is believed that inhibition of sulfate reduction may provide a means for reducing mercury mobilization and reducing transfer of this contaminant to the food web.
Sulfate reduction in sediments represents one step in a series of redox reactions in which labile organic carbon is metabolized yielding energy to support microbial populations. In this ecological redox series oxygen, nitrate, manganese, iron and sulfate are utilized, in sequence, as electron acceptors, with the reaction turning to methanogenesis when the electron acceptors are ultimately depleted. In Onondaga Lake, where manganese and iron concentrations are naturally low, the sequence is simplified to oxygen nitrate sulfate. The utilization of nitrate as a means of mercury sequestration is derived from the concept that sulfate reduction, and thus mercury methylation, can be inhibited by maintaining appropriate levels of nitrate in the hypolimnion.
An evaluation of the feasibility of nitrate addition as a means of inhibiting mercury methylation in Onondaga Lake sediments has raised questions relating to the amount of nitrate addition required annually, the role of METRO and a METRO diversion on the nitrate requirement and the time frame for reduction in or elimination of the requirement for nitrate addition as the labile carbon content of the lake sediments approaches equilibrium with new levels of productivity.
Here, we apply a mass balance model simulating labile organic carbon diagenesis and related redox chemistry to estimate the annual nitrate requirement. Next the model is utilized to evaluate the impact of METRO diversion and natural variability in tributary discharges on the annual nitrate requirement. Finally, we utilize the results of experimental studies of carbon lability to examine the time course of change in nitrate demand as the lake moves toward a steady state condition in equilibrium with new external phosphorus loads and attendant primary production.
Title: Resuspension of Sediments and Mercury from Near-Shore Waste Deposits in Onondaga Lake
Authors:
Revital Bookman, and Charles T. Driscoll
Syracuse University, Syracuse, NY
David Matthews, Steven W. Effler., and Emmet Owens
Upstate Freshwater Institute, Syracuse, NY
Abstract: In this research we studied the resuspension of sediment and associated mercury (Hg) from near-shore deposits of the Onondaga Lake "in-lake waste deposit". The waste deposit delta has been identified in the near-shore zone in the southwest corner of the lake. A former chemical manufacturing facility located along the western shore supplied Hg to Onondaga Lake.
Our research main objective is to document and evaluate the changes in sediment and Hg resuspension and deposition patterns in the in lake waste deposit and the effects of this resuspension on the transport of Hg to the remainder of Onondaga Lake. Sediment traps were deployed and collected at a weekly resolution during the free-ice season at 2004 and 2005. Samples were analyzed for total suspended solids and total Hg. In 2004 samples were deployed at depths of 10 and 17 m at the long-term monitoring site at the southern basin. The total Hg concentration and flux ranges were 0.18-2.8 µg/g and 1.9-27.8 µg/m2-d, respectively, with no statistical difference between the different trap depths. Increases in Hg concentrations and deposition were evident toward the end of the study interval, following fall turnover. The temporal pattern in 2005 showed a much greater variability for the sampling period from May through November compared to the previous year. Increases in suspended solids and Hg deposition were evident during and following fall turnover of 2005 for all sites. Additionally in 2005 the traps were deployed in 8 sites radiating from the long-term monitoring site toward the in-lake waste deposit in water depths of 19 m (D), 18 m (C), 11 m (B 1-2), and 5 m (A 1-4). The deployments were within the epilimnion. All measured parameters showed a decrease in concentration and flux with increasing distance from the waste deposit (from A to D). Total suspended solids average concentration and flux decreased from 8.5 to 4.7 mg/L, and from 29.7 to 15.9 mg/m2-d, respectively from the in-lake waste deposit to the center of the south basin. Mercury average concentration and flux decreased from 7.3 to 1.6 µg/g, and from 251.0 to 24.7 µg/m2-d, respectively. These results depict resuspension and transport of sediments and associated Hg from the in lake waste deposit toward deeper parts of Onondaga Lake. The position that this resuspension was driven by wave action is supported by the correlation between the downward flux of resuspended sediments and shear stress from waves, as predicted by a successfully tested mechanistic wave model (Donelan/GLERL).
Title: Environmental and Professional Ethics in a Post Modern World: Integrated Problem Solving and Onondaga Lake
Authors:
Swiatoslav Kaczmar PhD
O'Brien and Gere Engineers, Inc, Syracuse, NY
and
Syracuse University, Syracuse, NY
Abstract:The past 300 years of "modern" history was a period of rapid and significant advances in science and technology. Much of this progress can be attributed to the separation of science from the influence of religious and political institutions of the time. The separation supported the professional practice of science and engineering as an independent, objective undertaking.
The advancement of science and technology was instrumental to the industrial revolution. New technology provided valuable goods and services, in a mostly unregulated manner. However, many current environmental problems can be attributed to the inability of science and government during the industrial revolution to work together to identify potential cultural, environmental and health impacts of new products and processes.
Social scientists, philosophers and others suggest that the world has now entered a "post-modern" period, heavily influenced by popular culture, where the separation between science and social, religious and governmental institutions is less pronounced. Reducing the separation provides for representation of a range of interests and promotes collaborative problem solving. However, it also introduces the potential for institutions to define science, for scientists to direct public opinion and policy, and risk perception to drive risk management.
A major challenge facing stakeholders, environmental scientists and regulators charged with improving and sustaining the environmental quality of Onondaga Lake is the application of an integrated "holistic" approach to assessing and communicating site conditions, establishing priorities and committing resources. This presentation examines roles and relationships between science, culture, institutions and individuals involved in environmental restoration. A set of principles to be considered by practitioners for the development of a professional and environmental ethic is proposed and identified.
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