| | Research Project Descriptions
LISS Research l Research Links
2006 funded projects
2004 funded projects
2002 funded projects
2000 funded projects
All projects are funded by the LISS research grant program unless otherwise noted. Grants Awarded in 2006
Linking Seafloor Habitat Mapping Protocols to Management and Policy Needs
Investigator: Dr. Peter J. Auster, National Undersea Research Center and Department of Marine Sciences, University of Connecticut
The objective of this project is to produce a singular flexible habitat classification protocol that can be used by a range of workers focused on the Long Island Sound region. The research component of developing the habitat classification protocol will be explicitly linked to those who will implement and use the map products derived from the protocol (i.e., to insure that map products are both user-friendly and user-useful). To accomplish this task, an initial email survey of managers, policy-makers, researchers, engineers and other stakeholders (fishers, energy industry, environmentalists, coastal land developers) will be conducted to ascertain the range of habitat attributes that they deem relevant in their work. This initial survey will assist in the identification of a set of habitat attributes that are common across user groups and in the selection of a range of published marine habitat classification schemes to test with existing data. An interactive workshop with representatives of all stakeholder groups will be convened to assess the utility of the range of classification approaches tested and determine where modifications for a final protocol are needed. The final protocol and example applications will be produced as a technical document for web delivery.
Multi-component Evaluation to Minimize the Spread of Aquatic Invasive Seaweeds and Harmful Algal Bloom Microalgae via Live Bait Vectors in Long Island Sound
Investigators:
Dr. Robert Whitlatch, Dr. Charlie Yarish, and Dr. Senjie Lin, University of Connecticut
Dr. George Kraemer, State University of New York, Purchase
The goal of this project is to quantify the importance of bait products and associated packing materials as vectors for the introduction of non-indigenous species and harmful algal bloom (HAB)-forming microalgae to Long Island Sound. Non-native, invasive seaweeds and HAB-forming organisms represent threats to the ecological and economic health of the Sound. Samples of bait will be examined for non-indigenous species and cultured to identify microscopic stages and HAB microalgae using molecular analysis. Specific outputs include reports of the frequency of non-native, invasive seaweeds and HAB-forming microalgae by taxon as functions of season and the location of bait product purchase. A workshop on the project’s findings will be held at the end of the research to bring together relevant stakeholders.
Development of a Long Island Sound-Specific Water Quality Index Using Cluster Analysis and Discriminant Analysis
Investigator: Dr. Pengfei Zhang, Department of Earth and Atmospheric Sciences, City College of New York
The objective of this project is to develop a Long Island Sound-specific water quality index. The water quality index will be computed using multivariate cluster analysis and discriminant analysis of a set of individual water quality indicators. A numerical water quality index (around -1 to 1) will result, with a value close to 1 indicating good water quality (oligotrophic), a value close to -1 indicating poor water quality (eutrophic), and a slight negative value representing mesotrophic conditions (intermediate water quality). The new method will be applied to the Long Island Sound water quality data (past 15 years at ~20 stations) collected by the Connecticut Department of Environmental Protection. Monthly water quality indices will be computed for every station, and seasonal and annual trends in the water quality indices will be examined. The outputs of this project include a new LIS-specific water quality index and an automated procedure for computing the index. The numerical water quality index will give clear indications of the trophic status of LIS waters for routine water quality assessments.
Grants Awarded in 2004:
A Biological-Physical Numerical Simulation Model for the Investigation, Prediction and Management of Oxygen Production and Consumption in Long Island Sound: Data analysis and model formulation
Investigators:
Dr. Nicole Goebel and Dr. James Kremer, University of Connecticut
Dr. Chris Edwards, University of California at Santa Cruz
The objective of this project was to develop a simple and accurate ecosystem model of oxygen dynamics in Long Island Sound. Unlike other models, the primary productivity component of this model was corroborated with site-specific measurements of oxygen production and consumption. The focus of these rate measurements on processes directly driving oxygen changes are especially suited to the simulation of the relationship among nitrogen loading, eutrophication, and hypoxia. Rates of primary production are fundamental to predictions of phytoplankton stocks, and primary production and phytoplankton stocks are directly related to predications of oxygen production and consumption. This model will help improve understanding of the processes that contribute to hypoxia in Long Island Sound. The results of this study suggest that simplifying the model to four state variables—nitrogen, phytoplankton, benthic organic matter and oxygen—can accurately describe primary productivity in LIS as well as similar ecosystems. However, the model does not perform as well in describing oxygen consumption in the LIS water column. On average, oxygen consumption measured in LIS was 2-10 times that predicted in the model. Further investigation on the balance between oxygen consumption and production suggests an additional carbon source or oxygen sink in LIS. Incorporation of these missing sources and/or sinks into the biophysical–physical LIS model could lead to a simple, accurate, and practical model for managing hypoxia in LIS. Final Report Summary Published paper: Goebel, N.L., J.N. Kremer. 2007. Temporal and spatial variability of photosynthetic parameters and community respiration in Long Island Sound. Marine Ecology Progress Series. Vol. 329 (Jan. 2007): 23-42.
Natural Isotopic Tracers for Anthropogenic Nitrogen in Long Island Sound
Investigators:
Dr. Mark Altabet, University of Massachusetts
Dr. Johan Varekamp, Wesleyan University
The objective of this project is to quantify the impact of anthropogenic nitrogen loading to Long Island Sound with respect to natural sources. Innovative geochemical tools called isotopic tracers will be used to characterize the nitrogen sources to the Sound. This approach permits the assessment of the actual contribution of anthropogenic nitrogen to Long Island Sound’s nitrogen inventory. These results will help improve our understanding of the relationship between anthropogenic nitrogen loading and eutrophication. Final Report Summary
Food Webs in Long Island Sound: Review, Synthesis and Potential Applications
Investigators:
Dr. Roman Zajac, University of New Haven
Mr. Dave Simpson, CT Department of Environmental Protection
The objective of this project is to develop conceptual and quantitative food web models for different habitats in Long Island Sound. Using these models, the researchers will assess the critical food web components in each habitat type and identify data gaps in the present understanding of major food web components and their potential interactions. These models can be used to develop simulations and analyses to evaluate the impacts of management decisions on food webs and ecosystem dynamics in Long Island Sound.
Application of Remote Sensing Technologies for the Delineation and Assessment of Coastal Marshes and their Constituent Species
Investigators:
Dr. Daniel Civco, University of Connecticut
Dr. Martha Gilmore, Wesleyan University
The objective of this project is to identify and delineate coastal marshes around Long Island Sound and distinguish various types of marsh vegetation using moderate and high resolution remote sensing satellite imagery coupled with in situ radiometry and other field data collection. The researchers will identify and inventory the current extent and condition of the Sound’s coastal marshes and develop a cost-effective way to track changes in the condition of wetlands over time. These datasets and protocols can help provide coastal resource managers, municipal officials and researchers with baseline information for current land management and for long-term monitoring of habitat changes. Final Report Summary
Understanding the Role of Nutrient Enrichment in Tidal Marsh Loss in Long Island Sound
Investigator: Dr. Shimon Anisfeld, Yale University
The objective of this project is to test the hypothesis that excessive loading of nutrients (nitrogen or phosphorus) plays a role in causing tidal marsh loss. Tidal marsh loss due to drowning (i.e., loss of elevation relative to sea level and conversion of vegetated marsh to mudflat) has been observed in recent years in Long Island Sound, primarily in the western Sound. However, the mechanisms and causes of this marsh loss are poorly understood. The results of this research will help ascertain if nutrient loading is a factor in tidal marsh loss and, if so, identify which nutrient is likely responsible. Final Report Summary
Temporal and Spatial Changes in Copper Speciation and Toxic Metal Concentrations in Long Island Sound: Effect of changes in water temperature and dissolved oxygen levels
Investigator: Dr. Sergio Sañudo-Wilhelmy, Stony Brook University
The objective of this project is to establish the chemical speciation and vertical profiles of dissolved and particulate toxic metals in the water column in Long Island Sound. Dissolved metals undergo many changes in the estuarine environment, and this research will provide valuable information regarding the temporal and spatial variations in the chemical speciation of dissolved copper in the Sound. This research will also provide resource managers with critical information regarding the distribution of toxic metals both in the water column and throughout Long Island Sound. These factors are important for evaluating the health of Long Island Sound and examining the bioavailability of metals in the water column. This research also may support future ecotoxicology studies in the Sound. Final Report Summary
Assessment of the Effects of Bottom Water Temperature and Chemical Conditions, Sediment Temperature, and Sedimentary Organic Matter (Type and Amount) on Release of Sulfide and Ammonia from Sediments in Long Island Sound: A laboratory study
Investigators:
Dr. Carmela Cuomo, University of New Haven
Dr. Paul Bartholomew, Superb Technical
The objective of this project is to collect data on the release of sulfide and ammonia from sediments exposed to an array of environmental conditions. The researchers will conduct a series of laboratory experiments in which sediment collected from western Long Island Sound will be exposed to conditions that are representative of the spring, summer and fall. Previous studies have demonstrated that exposure to hydrogen sulfide and ammonia, in the presence of elevated water temperatures, can cause significant weakness and mortality in lobsters. This research will examine the fluxes of ammonia and sulfide from the sediments and any associated changes in bottom water dissolved oxygen levels, relative to certain environmental variables. These data will aid in the understanding of the development and abatement of seasonal hypoxic conditions in the western Sound and the role that sediment organic matter and sediment oxygen demand play in such events. Report Summary Nitrogen attenuation in the Connecticut River, northeastern USA; a comparison of mass balance and N2 production modeling approaches
Investigators:
Thor E. Smith, U.S. Geological Survey
Andrew E. Laursen, Ryerson University
Jeffrey R. Deacon, U.S. Geological Survey
The Connecticut River is a significant source of nitrogen to Long Island Sound, where high nitrogen loads cause seasonal hypoxia. To respond to this problem with effective strategies for reducing nitrogen loads in the Connecticut River, it is important to determine the rate and location of nitrogen loss during downstream transport to the Sound. Recent research has investigated the sources and transport of nitrogen in the Connecticut River basin, but the extent to which nitrogen is lost during transport remains unclear. The objective of this study, therefore, was to assess the degree and variability of nitrogen attenuation in the Connecticut River by making measurements in two reaches of the river during two different seasonal flow regimes (spring and summer). In this study, the methods of mass balance and N2 measurements were used independently to estimate the rates of in-stream nitrogen loss. A mass balance on nitrogen inputs and output for two study reaches (55 km southern reach and 66 km northern reach) at spring high flow (April 2005) and at summer low flow (August 2005) was computed on the basis of total nitrogen concentrations and measured river discharges in the Connecticut River and its tributaries. In a 10.3 km subreach of the northern reach, concentrations of dissolved N2 were also measured during summer low flow and compared to modeled N2 concentrations to determine the measured “excess” N2 that indicates denitrification. Mass balance results showed no in-stream nitrogen loss in either reach during April, and no nitrogen loss in the southern reach during August. In the northern reach during August, however, nitrogen output was 18% less than the total nitrogen inputs to the reach. N2 sampling results gave an estimated rate of N2 production that would remove 3.3% of the nitrogen load in the river over the 10.3 km northern subreach. The nitrogen losses measured in the northern reach in August may represent an approximate upper limit for nitrogen attenuation in the Connecticut River because denitrification processes are most active during warm summer temperatures and because the study was performed during the annual low-flow period when total nitrogen loads are small.
Published paper: Smith, T.E., Laursen, A.E., and Deacon, J.R., 2008, Nitrogen attenuation in the Connecticut River, northeastern USA; a comparison of mass balance and N2 production modeling approaches: Biogeochemistry, v. 87, no. 3, p. 311-323
This investigation is funded through the EPA’s Regional Applied Research Effort (RARE) program.
Grants Awarded in 2002:  Back to top
New Approaches for Assessing Mutagenic Risk of Contaminants in the Long Island Sound Environment
Investigators:
Dr. Anne McElroy, Stony Brook University
Dr. Lynn Mendelman and Dr. Richard Setlow, Brookhaven National Laboratory
The objectives of this project were to evaluate the potential capacity of contaminants in the sediments of Long Island Sound to cause mutations in vertebrates and to determine the types of mutations induced and the classes of contaminants responsible for these mutations. The researchers collected sediment samples from the Sound and identified those samples that were mutatoxic. Eggs from a fish species that is particularly susceptible to environmental mutagens were then exposed to the mutatoxic sediments from six sites. After the eggs hatched, the fish larvae were examined to determine the mutation frequency related to the sediment samples. Mutation frequency in the fish embryos increased after exposure to sediments from only one of the LIS sites. The sediment sample from this site contained extremely high levels of polycyclic aromatic hydrocarbons (PAHs). Results illustrate that transgenic embryos can be used to help quantify and characterize mutations induced by exposure to environmental mutagens. Data from this small-scale study also indicate that the mutagenic risk of LIS sediment contaminants to vertebrate organisms is generally low. The researchers recommended that additional work to evaluate the mutagenic risk of sediments at contaminated urban sites be conducted to substantiate their preliminary findings. Final Report Summary Published paper related to grant: McElroy , A.E., A.D Bogler, D. Weisbaum, M. Norris, L.V. Mendelman, R. Setlow, and R Winn. 2006. Uptake, metabolism, mutant frequencies and mutational spectra in transgenic medaka embryos exposed to benzo[á]pyrene dosed sediments. Marine Environmental Research .62(2006): 273-277.
Phytoplankton Dynamics in Long Island Sound: Influence of environmental factors on naturally occurring assemblages
Investigators:
Dr. J. Evan Ward, University of Connecticut
Dr. Kevin Strychar, Dalhousie University
Dr. Gary Wikfors, National Marine Fisheries Service
The objective of this project is to determine how phytoplankton dynamics differ in Long Island Sound along an eutrophication gradient (from east to west) and with the seasons. The researchers are also examining which environmental factors (i.e., nutrients, hypoxia or temperature) are the best predictors of phytoplankton assemblages. Phytoplankton are important primary producers that fuel coastal marine food webs. Nutrient over-loading, eutrophication and pollution can alter phytoplankton abundance and community structure. Such changes can lead to the degradation of food webs that support commercially valuable finfish species. This work will help advance the understanding of linkages among nutrients, phytoplankton and hypoxia. This information will have important implications for the long-term management of Long Island Sound and for the development of strategies to protect and restore the Sound’s living marine resources.
Final Report Summary
Saltmarsh-breeding Sparrows in Long Island Sound: Status and productivity of globally important populations
Investigators:
Dr. Chris Elphick and Dr. Margaret Rubega, University of Connecticut
Mr. Patrick Comins, National Audubon Society
The objective of this project is to compare a variety of methods for estimating saltmarsh sparrow abundance along the central Connecticut coast and identify the simplest, most cost-effective method for providing accurate population estimates. Saltmarsh sparrows are high priority species for bird conservation in New England. However, little is known about the status of these birds and methods for measuring their abundance are not well developed. Data gaps that these researchers are working to address include detailed information on population sizes, within-marsh habitat selection, and productivity. Evaluating the productivity of populations in key marshes is essential to determining the health of these populations and understanding the underlying environmental factors that influence reproductive success, breeding density and species occurrence is fundamental to effective management. Using data regarding what features influence nest site placement, the researchers are developing models that will be used to predict the consequences of a variety of habitat changes that may arise in the future and to compare alternative management scenarios. Data collected on marsh bird assemblages at each study plot is also being compiled by the researchers in order to evaluate options for developing useful indicators for the health of the bird communities in Long Island Sound saltmarshes. Final Report Summary Additional information on this project is available at the following website:
http://hydrodictyon.eeb.uconn.edu/people/birdlab Published paper related to grant: Gjerdrum, C., C.S. Elphick, and M. Rubega. 2005. What determines nest site selection and nesting success in saltmarsh breeding sparrows? Condor 107:849-862.
Water Column Oxygen Production and Consumption in Long Island Sound: Measurements and coupled bio-physical modeling
Investigators:
Dr. James Kremer and Dr. Nicole Goebel, University of Connecticut
Dr. Chris Edwards, University of California at Santa Cruz
The objectives of this project are to measure water column oxygen production and consumption rates for Long Island Sound and to develop a coupled bio-physical simulation model of the Sound. These researchers are directly measuring plankton oxygen metabolism during the critical summer months in order to further the understanding of the processes leading to hypoxia in Long Island Sound. This study will improve the development and interpretation of the water quality models applied to the Sound by providing field measurements of planktonic oxygen production and consumption rates. The researchers are also developing a new model with which the relevant biological and physical processes that lead to eutrophication and hypoxia in the Sound can be analyzed. The results of this work will help inform planning and management decisions regarding hypoxia in the Sound. Final Report Summary Published paper: Goebel, N.L., J.N. Kremer, and C.A. Edwards. 2006. Primary Production in Long Island Sound. Estuaries and Coasts. Vol. 29, No. 2 (April 2006): 232-245.
Western Long Island Sound Hypoxia: Isotope tracers of the East River nitrate pump
Investigator: Dr. Richard Fairbanks, Columbia University
The objective of this project was to assess the contribution of discharge from the East River to hypoxia in western Long Island Sound using isotope tracers of East River water and organic particulate matter. Isotope tracers, in addition to concentration data, allow researchers to identify the sources and mixing history of water and particulates entering western Long Island Sound. This researcher investigated the processes and pathways governing the sequestration of nitrogen and phosphate from the East River. Using isotopic tracers to follow the delivery of East River-derived nitrate and phosphate to the hypoxic region, a map of the concentration and volume of East River water in the western Sound during the development of hypoxia was produced. The unique results of this study indicate that four small, deep basins act as “hypoxia incubators” on the seafloor of the western Sound and that these basins spread hypoxia throughout the water column. Nitrogen isotope tracers demonstrate that the organic particulates sampled in the deep basins derive their nitrogen almost entirely from wastewater effluent. Oxygen isotope measurements of water molecules indicate that tidal mixing maintains a high percentage of East River water directly overlying the site of initial hypoxia in the western Sound. Isotope data also show that the eastward spread of low oxygen waters is due to tidal and current mixing with the extremely low oxygen waters pooling in the four deep basins. Based on these findings, the researcher recommends that managers target hypoxia abatement strategies at these four restricted basins in order to address the immediate source of the problem. It is also recommended that a hypoxia abatement experiment be conducted in the smallest basin using isotope and purposeful tracers. Final Report Summary Back to top
Grants Awarded in 2000:
Trace Metals, Organic Carbon and Inorganic Nutrients in Surface Water of Long Island Sound: Sources, cycling and effects on phytoplankton growth
Investigators:
Dr. Sergio Sañudo-Wilhelmy, Stony Brook University
Dr. Christopher Gobler, Southampton College
The objective of this project was to establish the concentration and distribution of dissolved metals and inorganic nutrients in the surface waters of Long Island Sound and to examine the relative importance of various sources (i.e., riverine inputs, sewage) of these nutrients and metals. Preliminary results indicated that the East River is the most dominant external source of trace metals during low flow conditions, but the Connecticut River is the most important external force during high flow conditions. Large internal sources of copper, nickel and zinc were detected under low flow conditions, highlighting the potential importance of internal processes such as remobilization from contaminated sediments in the Sound. The researchers recommended that additional work, such as the direct measurement of diffusive benthic fluxes, be conducted to substantiate their preliminary findings. Final Report Summary Published Papers:
Sweeney , A., S. A. Sanudo-Wilhelmy. 2004. Dissolved metal contamination in the East River-Long Island Sound system; potential biological effects. Marine Pollution Bulletin 48, pp
663-670.
Sanudo-Wilhelmy, S. A., A. Tovar-Sanchez, N. Fisher, A. Russell
Flegel. Jan. 15, 2004. Examining Dissolved Toxic Metals in U.S. Estuaries, Environmental Science and Technology, pp 34a-38a.
Environmental Change in Long Island Sound over the Last 400 Years
Investigators: Dr. Johan Varekamp, Dr. Ellen Thomas, and Dr. Kristina
Beuning, Wesleyan University
The objective of this project is to document the environmental transition in Long Island Sound from pre-colonial times to the present day using sediment cores. The researchers are constructing the levels of dissolved oxygen, the abundance of sewage effluent, turbidity, local productivity of organic carbon, the terrestrial influx of organic carbon, and the levels of toxic metal contamination in Long Island Sound over the last 400 years. They are also gathering data regarding the ecosystem changes associated with these factors. Data indicate that sewage derived from humans led to the overfertilization of the Sound, to hypoxia, and to fundamental changes in the abundance and types of animal and plant life. This research will provide information on the present state of health of the Long Island Sound ecosystem, as well as the history of anthropogenically-induced changes in this ecosystem. Final Report Summary
Assessment of the Causes and Extent of Morbidity and Mortality of American Lobsters (Homarus americanus) in Long Island Sound
Investigators:
Dr. Richard French, Dr. Sylvain DeGuise, Dr. Salvatore Frasca, Jr., Dr.
Christopher Perkins and Mr. Spencer Russell, University of Connecticut
Mr. Ernie Beckwith, Connecticut Department of Environmental Protection
Mr. Byron Young, New York State Department of Environmental Conservation
The objective of this project was to analyze lobsters from Long Island Sound to identify pathology, possible disease-causing micro-organisms, and contaminant levels as a means of assessing the general health status of the Sound’s lobster populations. Lobster health parameters were studied relative to environmental conditions, regional habitat, contaminants, and population and disease dynamics. A paramoeba (protozoan organism) was identified as a proximate cause of lobster mortalities in a significant portion of the lobsters autopsied from western Long Island Sound, and new methodologies to detect paramoebiasis in the tissues of lobster are under development. In the eastern Sound, chitinolytic shell disease was found to be prevalent, and ongoing efforts to define the pathogenesis of the disease have yielded significant results. Toxicological analysis of lobster tissues did not identify detectable levels of pesticides known to be used in mosquito management. However, levels of other contaminants, including heavy metals, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), were detected. The results of this research indicated that the health of the Sound’s lobsters is impacted by at least two significant diseases (paramoebiasis and chitinolytic shell disease) and that these diseases could be exacerbated by environmental stressors, such as climatic and habitat conditions and contaminants. The researchers recommended that a continuous surveillance system, including routine sampling and participation by lobstermen, be established in order to manage unexpected events such as disease, mortalities and declines in Long Island Sound’s lobster populations. Final Report Summary Monitoring of Bottom Water and Sediment Conditions at Critical Stations in Western Long Island Sound
Investigators:
Dr. Carmelo Cuomo, Department of Geology & Geophysics, Yale University
Mr. Raymond Valente, Marine Environmental Science & Information Management Division, Science Applications International Corporation
One of the issues central to management of the lobster fishery in western Long Island Sound is the condition of bottom waters with regards to hypoxia. The onset of hypoxia in western Long Island Sound results from the interplay of many different factors, including air and water temperature, rainfall, currents, amount and type of organic matter, initial bottom water oxygen levels, anthropogenic inputs, and degree of stratification. The individual contribution made by any of these factors can vary from year to year. This project evaluates the role of hypoxia and anoxia (and related sulphide and ammonia releases from the sediment) as a structuring influence on the benthic environment and communities of western Long Island Sound, especially as they pertain to lobster habitat. It is hypothesized that long-term exposures to low oxygen and high levels of ammonia (and perhaps hydrogen sulphide) may have induced a physiologically-stressed state in the lobsters that died in 1999, weakening their immune system, and setting them up for disease. Final Report Summary
Published papers:
Cuomo, C., R.M. Valente, and Deren Dogru. 2005. Seasonal Variations in Sediment and Bottom Water Chemistry of Western Long Island Sound for Lobster Mortality. Journal of Shellfish Research, Vol. 24, No. 3, (2000): 805-814
Valente, R.M. and Cuomo, C. Did Multiple Sediment-associated Stressors Contribute to the 1999 Lobster Mass Mortality Event in Western Long Island Sound, USA Estuarine Research Foundation, Vol. 28, No. 4 (August 2005): 529-540. Back to top |
