Investigators: Penny Vlahos and Michael Whitney, University of Connecticut; Peter Linderoth, Save the Sound; Katie O’Brien-Clayton, CT DEEP
Time Period: 2021 to 2023
Total alkalinity and aragonite saturation in river-fed embayments in Long Island Sound differ greatly based on water quality and land use patterns and have significant implications for shellfish yields. This project will conduct the first assessment of alkalinity in the Sound’s embayments, with the goal of measuring and analyzing four key variables in the carbonate alkalinity system: total alkalinity, pH, partial pressure of carbon dioxide and dissolved inorganic carbon. This will contribute to an understanding of the range of buffering capacity and resilience across the Sound to acidification and link this to nutrient loading and local conditions. The results will provide an in-depth analysis of spatial and temporal variability along with management-scenario testing. Maps of alkalinity and aragonite saturation will be developed by combining observations and simulation results to identify areas that are resilient or vulnerable to changes in pH across regions through engagements of stakeholder groups across the coastline. Additionally, the project will identify aragonite saturation rates at these embayments to determine the occurrence of low saturation periods that are a risk to shellfish.
Investigators: Craig Tobias and James O’Donnell, University of Connecticut
While efforts to reduce nutrient loads have reduced hypoxia in Long Island Sound, there is still a need to better understand how controls on bottom water oxygen and nutrient reduction translates into a hypoxia recovery trajectory. This project is designed specifically to inform how to improve models of bottom water hypoxia by using oxygen isotopes to tackle two fundamental questions:
This will be done through both field measurements and laboratory experiments to measure water column oxygen metabolism and quantify the vertical and horizontal mixing of oxygen. Laboratory experiments will measure the isotope effect of water column and benthic respiration associated with oxygen loss. The project will develop and validate a coupled hydrodynamic hypoxia simulation model of oxygen and its isotopic composition in the surface and bottom waters.
Investigators: Beth Lawrence, Ashley Helton, and Chris Elphick, University of Connecticut; Min Huang, CT DEEP
Rising seas and limits to marsh migration pose serious threats to remaining Long Island Sound tidal marshes and the services they provide. Implementing restoration techniques that build elevation and promote coastal resilience, such as placement of sediments, is key to tidal marsh maintenance and a high priority for regional managers. This research will address the critical need for well-tested guidelines examining how sediment sizes and textures as well as tidal range alter the effectiveness of sediment applications for marsh restoration. The project will measure sediment, plant, and carbon flux responses to experimental treatments and compare responses in three marshes. These field experiments will help inform management decisions in real time and ultimately help enhance coastal resiliency. The project will evaluate whether small-scale placement experiments are representative of management-scale applications and promote better understanding of sea level rise, coastal wetlands, and marsh restoration among diverse stakeholders.
Investigators: Ashley Helton, Chester Arnold, Emily Wilson, and David Bjerklie, University of Connecticut; Wilfred Wollheim, University of New Hampshire; Mary Becker and Chris Bellucci, CT DEEP; Paul Stacey, Footprints in the Water LLC
Researchers will develop a computer model to analyze historical trends back to the 1970s to project the environmental conditions of Long Island Sound into the future. Stevens Institute of Technology will synthesize physical data collected for LIS and global climate change indices. The computer model will first model backward in time, a process called “hindcasting,” and will be compared to historic marine resources data provided by CT DEEP and a high-resolution global climate model from NOAA’s Geophysical Fluid Dynamics Laboratory. The computer model will then look forward to simulating the effects of climate on Long Island Sound’s physical environment and living marine resources up to the year 2100.
Investigators: Craig R. Tobias, University of Connecticut
Time Period: 2019 to 2021
Western Long Island Sound is the area of the Sound most vulnerable to low oxygen (hypoxic) conditions. The investigator will deploy automated respiration chambers at locations throughout the western Long Island Sound, including in the Bronx at Throggs Neck where the East River enters the Sound, and along the gradient of the Connecticut River plume, the largest source of non-urban freshwater and nutrients to the Sound. These devices will measure respiration and net ecosystem production at the above locations chosen for their differences in organic matter sources and composition, a major driver of these processes. The researcher will incubate parallel samples onboard the research vessel to compare with measurements from the automated respiration chambers and provide additional information. The results will address hypoxia by increasing our understanding and the predictability of how respiration responds to management actions.
Investigators: Penny Vlahos, Jamie Vaudrey, and Michael Whitney, University of Connecticut
Gaining a better understanding of how oxygen is being used in the water column of Long Island Sound will inform decisions that seek to avoid hypoxia and manage the estuary sustainably amidst coastal population growth and shifting climate. The research team will sample 10 sites across the Sound. The Connecticut Department of Energy and Environmental Protection’s monitoring vessel John Dempsey will provide access to the project. Components of the respiration process that will be quantified include organic matter degradation rates, nutrients, oxygen, carbon dioxide and controlling variables including pH, alkalinity and temperature. The field sampling will occur in different seasons and at various locations, allowing the timing and location of respiration rates to be predicted.
This project builds on analyses of carbon balances in the Sound being conducted by the investigators and will help develop a more detailed biogeochemical understanding to enhance Long Island Sound management.
Investigators: Nickitas Georgas, Alan F. Blumberg, and Philip M. Orton, Stevens Institute of Technology; Penelope Howell, CT Department of Energy and Environmental Protection Marine Fisheries Division; and Vincent S. Saba, NOAA/National Marine Fisheries Service Northeast Fisheries Science Center
Time Period: 2013-2016
Investigator: Christopher J. Gobler. School of Marine and Atmospheric Sciences, Stony Brook University
Time Period: 2011-2013
Harmful algal blooms (HABs) have increased globally, with growing negative impacts on human health, fisheries, and economies. In Long Island Sound (LIS), the composition of its primary producers has undergone a fundamental change during the past decade as intense toxin-producing dinoflagellate blooms of Alexandrium fundyense and Dinophysis acuminata have become annual events within nearshore regions. This two-year project is based on the hypothesis that this phase shift has been initiated by a series of anthropogenic alterations to LIS ecosystems including nitrogen loading, organic matter loading, and factors related to climate change including increasing temperatures and increasing CO2 concentrations. Determining the primary causes of dinoflagellate blooms that produce PSP and DSP (two shellfish poisons) in LIS will be the first step toward developing plans to control and mitigate these events. This project will generate near-real-time reports for the NYSDEC and the CT Dept. of Aquaculture regarding densities of the bloom organisms across NY and CT, serving as an early warning system for bloom events within the LIS ecosystem. Data will be made accessible to the public and information will be provided to regulatory and management agencies to protect human health and minimize the future impacts of toxic dinoflagellates on LIS. Final Report
Investigator: Gobler, Christopher J., School of Marine and Atmospheric Sciences, Stony Brook University
Time Period: 2009-2011
Research proposed by Christopher Gobler examining “The Distribution, Causes and Impacts of Alexandrium fundyense Blooms in Coves, Near Shore and Open Water Regions of Long Island Sound”, will provide insights into the development and dynamics of red tides, a serious, emerging human health threat in Long Island Sound. Paralytic shellfish poisoning is caused by the ingestion by shellfish of certain strains of algae which produce saxitoxin. Shellfish accumulate this toxin and can, when these contaminated shellfish are consumed by humans or another predator, cause sickness or even death. Alexandrium fundyense is the saxitoxin-producing plankton in the coastal waters of Long Island Sound. In recent years there have been widespread commercial and recreational closures of shellfisheries resulting from outbreaks of this organism. The research, a combination of both field-based pelagic sampling and experimental protocols, seeks to establish spatial and temporal patterns for the distribution of this organism and its cysts in relation to temperature, nutrients, and other components of the planktonic community. Lab experiments will assess factors that enhance or impede the growth of these toxin-producing cells. This research gives fisheries managers and local health departments the essential information they need to protect human health and sustain healthy ecosystems and local economies. Final Report
Investigator: Lonsdale, Darcy J., School of Marine and Atmospheric Sciences, Stony Brook University
Darcy Lonsdale and Christopher Gobler’s research, “Impacts of Climate Change on the Export of the Spring Bloom in Long Island Sound” examines the relationship between winter temperature and the abundance and composition of phytoplankton in the spring and explores potential impacts of changing winter water temperatures on local food webs. Their research, a combination of field collection and experimental lab work, will provide important insights into the potential impacts of climate change on marine systems in Long Island Sound. Water temperatures in Long Island Sound are increasing and warmer winter waters are associated with more zooplankton grazing. Grazing lowers phytoplankton growth, thus allowing the levels of nutrients, such as nitrogen, to remain high. These dynamic changes in production caused by a changing climate have serious implications for the development of hypoxic events, feeding relationships, and ultimately fisheries production in Long Island Sound. This exciting research constitutes a critical step in elucidating these relationships. Final Report
Investigators:Dr. Chris Elphick and Dr. Margaret Rubega, University of ConnecticutMr. Patrick Comins, National Audubon Society
Time Period: 2003-2005
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 are 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 SummaryFinal Report
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.
Investigators: Dr. Johan Varekamp, Dr. Ellen Thomas, and Dr. Kristina Beuning, Wesleyan University
Time Period: 2001-2003
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 SummaryFinal Report