2000 Research Project Descriptions

Trace Metals, Organic Carbon and Inorganic Nutrients in Surface Water of Long Island Sound: Sources, cycling and effects on phytoplankton growth

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
Final Report

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 US 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 Public Summary
Final Report

Assessment of the Causes and Extent of Morbidity and Mortality of American Lobsters (Homarus americanus) in Long Island Sound

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 Energy and 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
Final Report

Monitoring of Bottom Water and Sediment Conditions at Critical Stations in Western Long Island Sound

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
Final Report

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.

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