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Presentation Abstracts
Title:Biological invasions: causes and effects in the Great Lakes watershed
Author:
Edward Mills, PhD
Director of the Cornell Biological Field Station, Professor in the Department of Natural Resources, College of Agriculture and Life Sciences, Cornell University, and Co-Director of Research for the Great Lakes Research Consortium
Abstract:The Great Lakes of North America continue to be at risk from biological invasions associated with unplanned introductions from regions around the globe resulting from increasing world trade and travel. Existing connections between the Great Lakes watershed and systems outside the watershed, such as the Chicago Sanitary and Ship Canal, and growth of industries such as aquaculture, live food markets, and aquarium retail stores will also increase the risk that new species will be introduced. Human activities associated with shipping are responsible for over one-third of invasive species introductions in the Great Lakes, and there is no indication that introductions associated with this vector are decreasing. As we move into the future, factors such as changes in water quality, global climate change, and previous biological invasions may make Great Lakes waters a more hospitable environment for the establishment of new invaders, leading to continued uncertainty and ecological surprises.
Intentional and unplanned introductions have led to profound changes in the Lake Ontario ecosystem. The most notable management and ecological changes over the past four decades have been fisheries management efforts to control lamprey, large-scale stocking of Pacific salmon to control nuisance levels of non-native alewife, the proliferation of filter-feeding Dreissena, regime shifts in ecosystem processes, summer and early fall pulses of Cercopagis pengoi, and marked declines of key native species. Significant reductions in phosphorus with a concomitant shift toward oligotrophy and a dramatic increase in water clarity resulting from both nutrient reduction and proliferation of filter-feeding Dreissena spp. have favored benthic over pelagic energy pathways (especially in the nearshore and embayment habitats), a process termed benthification. Other food-web changes that have occurred in association with the establishment of invasive species include declines in native Diporeia, behavioral shifts in alewife spatial distribution, a shift in dominance from zebra mussels to quagga mussels, expansion of round gobies, and periodic outbreaks of botulism.
Title: What are water optical properties and why I care: an emerging technology for lake management?
Authors:
Alan Weidemann, Wesley Goode, ZhongPing Lee
Naval Research Lab
Steven Effler, David O'Donnell, Feng Peng, and
MaryGail Perkins
Upstate Freshwater Institute
Abstract:Water turbidity has long been recognized as an indicator of general water quality in lake management. However measurements of optical properties of the water have advanced significantly since the Secchi disk and nephelometric turbidity. In-situ water column optical properties and laboratory analysis are presented for two stations in Onondaga Lake (Deep South and River Marker 219) collected in June of 2004. Water properties such as dissolved organic material, phytoplankton absorption, total attenuation, and backscattering were measured in-situ, remote sensing reflectance was measured above the water surface, and laboratory analysis was conducted on particle properties and particulate/dissolved absorption. We contrast the optical properties at these two stations to demonstrate how optical properties can be used to define water body properties and assist in assessing water quality and long-term lake evolution. A comparison with laboratory measurements is used to show the reliability of the in-situ measurements and how particle properties can be inferred from these measurements. The organic to inorganic particle relationship is derived using the in-situ optical properties. Use of in-situ measurements for monitoring water quality is shown to be enhanced by the use of remote sensing information gathered using multispectral and hyperspectral sensors and inversion techniques. How these combined measurement techniques can be exploited for monitoring lake water quality is presented.
Title: Long-term trends in the hypolimnetic metabolism of Onondaga Lake, NY
Authors:
David A. Matthews and Steven W. Effler,
Susan M. O'Donnell, and Carol M. Matthews
Upstate Freshwater Institute
Charles T. Driscoll
Syracuse University
Abstract:Hypolimnetic electron budgets were developed for sulfate-rich, eutrophic Onondaga Lake, New York for the summer stratification intervals of 16 years (1989 – 2004) as a means to investigate seasonal, interannual and long-term changes in hypolimnetic metabolism. A mass balance approach was applied to the hypolimnion to estimate the consumption of electron acceptors (e.g., O2, NO3-) and production of reduced byproducts (e.g., HS-, CH4) associated with the oxidation of organic matter. The stoichiometry of the associated redox reactions supported calculation of electron transfer in the hypolimnion. In 11 of the 16 study years SO42- reduction was the most important decomposition pathway in the hypolimnion, accounting for an average of 33% of the dissolved inorganic carbon (DIC) accumulation. Aerobic decomposition (26%), methanogenesis (14%), and denitrification (9%) were also quantitatively important mineralization processes in the hypolimnion. We were unable to account for 18%, on average, of the DIC production with these oxidation reactions; possible explanations for this discrepancy are discussed. The relative importance of the various decomposition pathways to overall hypolimnetic metabolism varied widely in response to an abrupt decrease in organic carbon deposition in 1987, incomplete spring turnover in 1993 and 1994, and improved nitrification treatment at a contributing wastewater treatment facility in 2004. Changes in the importance of the different decomposition pathways were generally consistent with the thermodynamic constraints that regulate the spatial and temporal occurrence of redox processes in sediments.
Title: Implications of changing redox conditions and oxygen resources for application of oxygenation/aeration technologies as rehabilitation measures for Onondaga Lake, NY
Authors:
Steven W. Effler, and David A. Matthews
Upstate Freshwater Institute
Svetla Todorova, Charles T. Driscoll
Syracuse University
Abstract:A synthesis of the impacts of domestic and industrial wastes on the oxygen resources and redox conditions of polluted Onondaga Lake, Syracuse, NY, is presented based on a long-term (1978 – 2005) monitoring program. Insights from this retrospective analysis are used to evaluate management alternatives for the remediation of oxygen resources and redox conditions. High concentrations of reduced byproducts accumulated annually, causing low dissolved oxygen (DO) concentrations in the upper waters during fall turnover and potentially contributing to the mobilization of methyl mercury (CH3Hg) from contaminated sediments. These impacts have been promoted by the lake's high natural sulfate (SO42-) concentration. Severe depletions of DO occurred annually in the upper waters during fall mixing, representing violations of water quality standards for extended intervals in many years from 1978 to 1996. Depletions of DO were less severe from 1997 to 2004. The improvement is reported to be in response to: (1) more routine occurrence of spring turnover following closure of an industry, (2) reduction in primary productivity, (3) return of large bodied Daphnia from closure of the industry, (4) satisfaction of historic debt from earlier higher primary production levels, and (5) year-round nitrification at a contributing domestic wastewater facility, which reduced in-lake ammonia levels and increased nitrate (NO3-) levels to support denitrification-based decomposition. Additional improvements in oxygen resources and decreases or elimination of antecedent SO42- -reduction in the hypolimnion are anticipated based on mandated future upgrades of phosphorus and ammonia treatment at the wastewater facility. Prevailing DO conditions during fall turnover, particularly within the context of anticipated improvements from the mandated upgrades, indicate hypolimnetic aeration/oxygenation is not required to meet related enforcement goals. Increases in the lake's hypolimnetic pool of NO3- associated with wastewater treatment upgrades, and augmented as necessary to prevent SO42- -reduction, are recommended instead of aeration/oxygenation to inhibit formation of methyl Hg by SO42- -reducing bacteria.
Title: Model of zebra mussel growth and water quality impacts in the Seneca River, Part 1: water quality
Authors:
James R. Rhea, Daniel R. Opdyke, Kevin T. Russell, C. Kirk Ziegler, Wen Ku, Li Zheng, David Glaser
Quantitative Environmental Analysis, LLC
Joseph Mastriano
Onondaga County Department of Environment Protection
Abstract: The Seneca River, NY is on New York State's 303(d) list of impaired water bodies for non-attainment of dissolved oxygen criteria and is being considered as the potential receiving waters for the diverted effluent from an 85 MGD wastewater treatment facility serving the City of Syracuse, NY. To examine the feasibility of such a diversion, a dynamic water quality model of the Seneca River was developed. The model incorporates two-dimensional hydrodynamics to simulate stratification observed within the system, a carbon-based zebra mussel growth model to account for the impact of this invasive species on water quality within the system, a mechanistic representation of sediment diagenesis to account for zebra mussel-induced changes in carbon cycling, and water quality kinetics. The model was parameterized using site-specific field and laboratory studies and accurately simulates six years of routine river monitoring data collected over a range of flow conditions. The diagnostic application of the calibrated model provided valuable insights into the complex feedback mechanisms that exist within the system, particularly the role that zebra mussel filtration, respiration, and elimination have on phytoplankton production, sediment oxygen demand, and nutrient cycling within the system. Ultimately, the river model will be linked to an Onondaga Lake watershed and lake model to form an integrated water quality management tool for the system.
Title: Model of zebra mussel (Dreissena polymorpha) growth and water quality impacts in the Seneca River, Part 2: zebra mussels
Authors:
David Glaser, James R. Rhea, Daniel R. Opdyke, Kevin T. Russell, Wen Ku
Quantitative Environmental Analysis, LLC
Joseph Mastriano
Onondaga County Department of Environment Protection
Abstract: The Seneca River, NY is on New York State's 303(d) list of impaired water bodies for non-attainment of dissolved oxygen criteria and is being considered as the potential receiving waters for the diverted effluent from an 85 million gallons per day (MGD) wastewater treatment facility serving the City of Syracuse, NY. Water quality management has been complicated by the presence of zebra mussels (Dreissena polymorpha), which have reduced dissolved oxygen and chlorophyll-a levels and increased dissolved phosphorus and ammonia levels in the river. To assist with decision-making, a water quality model was developed. This model incorporates a submodel describing zebra mussel impacts on water quality due to filtration, respiration and nutrient regeneration, as well as zebra mussel growth. Constraints provided by the requirement to match multiple water quality parameters as well as observed zebra mussel growth reduce overall model uncertainty. The dynamic growth model permits realistic representation of changes in water quality throughout the growing season. The model provides an example of reducing model uncertainty by incorporating recent scientific understanding of zebra mussel biological processes, as well as extensive laboratory and site-specific data.
Title: A Modeling analysis of the clear water phase in Onondaga Lake
Author:
Martin T. Auer
Michigan Technological University
Abstract: Many lakes experience a clear water phase in spring. Over this two–six week period, grazing by large crustacean zooplankton reduces phytoplankton populations, leading to striking increases in transparency. Following the clear water phase, chlorophyll levels rebound and transparency is reduced, but usually not to levels associated with the spring phytoplankton bloom. In addition, a marked shift in the species composition of the phytoplankton occurs, with easily grazed species (small green algae, cryptomonads, small diatoms) being replaced by those resistant to grazing (cyanobacteria, large green algae). The spring clearing event is a classic example of a 'top-down' phenomenon, having much in common with the concepts of biomanipulation applied in lake management.
A quantitative treatment of clearing events requires modeling proficiency at multiple levels (nutrients, phytoplankton, zooplankton and fish), imparting a high degree-of-difficulty to the task. The modeling exercise, described here for Onondaga Lake, considers three cases: one (1985), in which large grazers are absent and no clearing events occur, a second (1999) where large grazers are abundant and striking periods of high transparency are noted and a third (2003) where large grazers are once again absent and transparency remains low. An effort is made to mechanistically simulate the role of planktivorous fish in mediating the transition from the high grazing pressure scenario of 1999 to conditions in 2003 when large zooplankton were absent and no clearing events occurred.
Modeling is conducted within the framework of U.S. EPA's AQUATOX software. This package offers a remarkable degree of flexibility in populating a target system with plants and animals and in tailoring the physiological attributes of those species to a particular modeling task. The success of the model in simulating conditions during the three years varies, as expected, with the complexity of the system. In 1985, the model focuses on phytoplankton in a nutrient-saturated system with no large grazers and serves well in predicting algal standing crop (chlorophyll) and Secchi disk transparency. The 1999 simulation satisfactorily accommodates the role of increased grazing pressure, but suggests that particles other than phytoplankton must be removed from the system in order to match observed changes in transparency. The final simulation, in which predation pressure by fish eliminates grazing zooplankton, successfully predicts a return to high algal biomass – low transparency conditions, but appears to test the limits of mechanistic, mass balance modeling in accommodating the role of higher organisms.
Title: Variation in populations of Daphnia mendotae over space and time
Author:
Jennifer A. Fox
Drew University
Abstract: Many annual-plant and invertebrate species produce seeds or eggs that can survive in dormancy for many years before germinating or hatching. The resulting seed or egg banks store the record of changes in genetic structure of populations and have the potential to influence ongoing population processes. I studied these processes for the freshwater crustacean Daphnia mendotae following the establishment of this species in Onondaga Lake following a reduction in pollution inputs. I investigated (1) the history of genetically-based phenotypic change recorded by the egg bank and (2) the neutral genetic variation contained within the egg bank of one lake and in water column populations of many lakes.
A growth study of clones derived from 15-20-year-old sediments and < 5-year-old sediments in Onondaga Lake showed that important fitness characters have changed over this time period. D. mendotae evolved to mature significantly faster and variation for important life history traits decreased over a period of about 15 years, consistent with a response to an increase in predation pressure from fish following reduction of pollution inputs.
I developed seven microsatellite loci for D. mendotae and used them to assay genetic variation over time following a new founding event. Neutral genetic variation was initially high and stayed high, showing that different processes influence life history genetics and neutral genetics. In addition, D. mendotae populations in several lakes in New York state show mixed ancestry between North American D. mendotae and European D. galeata, suggesting a cryptic invasion by European D. galeata. There is otherwise little geographic variation among populations of D. mendotae across the Northeastern United States.
Title: Comparisons of an urban lake targeted for rehabilitation and a reference lake based on robotic monitoring
Authors:
Joeseph S. Denkenberger, Charles T. Driscoll
Syracuse University
Steven W. Effler, David M. O'Donnell and David. A. Matthews
Upstate Freshwater Institute
Abstract: A reference lake, Otisco Lake, NY, is selected to evaluate rehabilitation initiatives to mitigate severe cultural eutrophication of Onondaga Lake, NY. Onondaga Lake had been mesotrophic before European development. This selection is based on an analysis of paired monitoring datasets for temperature, fluorometric chlorophyll (Chlf/a) and dissolved oxygen (DO), collected daily by robotic profiling platforms for the spring to fall interval of three years. The use of Otisco Lake as a reference site is supported by its very similar stratification/mixing regime and mesotrophic state, in addition to its proximity (~25 km) and similar morphometry. Strong contrasts in water quality manifestations of trophic state are depicted, including higher Chlf/a (3.5-fold), prevalence of blooms, greater deviations of DO from saturation conditions, much lower minimum DO values at fall turnover in the upper layers and a higher volumetric hypolimnetic oxygen deficit (VHOD; 1.55-fold), in Onondaga Lake. Advantages of the fine vertical and temporal scale capabilities of the monitoring platforms are demonstrated in characterizing these and other limnological features. The various metrics of trophic state documented here for Otisco Lake represent reasonable informal interim goals for the rehabilitation of the cultural eutrophication problems of Onondaga Lake. Inclusion of continued robotic monitoring at Otisco Lake, as a reference site, and Onondaga Lake through the rehabilitation program will support ongoing comparisons to assess progress and will promote engagement of stakeholders in the process.
Title: A geostatistical analysis of the extent and toxicity of contaminated sediments in Onondaga Lake, Syracuse, NY
Authors:
Myrna H. Hall, Jerry V. Mead, and Patricia F. Thompson
SUNY CESF
Donald J. Hughes
Onondaga Lake Cleanup Corp.
Abstract: Onondaga Lake was designated a Federal Superfund site in 1994 due, in part, to extensive sediment contamination. To date no studies have quantified the extent nor degree of harm posed by these contaminants. We applied geostatistical modeling techniques to assess the extent and severity of contamination throughout the top 30-cm of sediments. This analysis incorporates data from 132 core samples collected in years 1992 and 2000. We then calculated the toxicity levels for benthic (bottom dwelling) organisms using the New York State sediment screening criteria guidelines (DEC, 1999). Our analysis shows that in the southwest corner of the lake, BTEX (benzene, toluene, ethylbenzene, and xylenes), chlorinated benzenes, PAHs (polyaromatic hydrocarbons), and mercury are all present at concentrations well in excess of the sediment screening criteria. The central and northern portions of the lake are much less affected by the organic compounds that we examined, but are still highly contaminated by mercury. Approximately 950 hectares (79% of the benthos) are above 1.3 ppm Hg--a level expected to cause "severe" toxicity to benthic organisms. Chlorinated benzenes occur at concentrations up to 3600 times NYS screening level criteria, but over a much smaller area. Thus, it is likely that restoration of the benthos of the lake would require significant remedial actions, such as removal and/or capping of sediments
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