The coastal waters of Southern New England and New York have lost extensive areas of eelgrass habitat (Zostera marina L.), a type of seagrass. The cause of this decline is multifaceted and based within a series of multiple stressors. These include the effects associated with increasing and chronic excess nutrient (primarily nitrogen) loads in combination with other environmental stressors such as thermal stress, changes in landscape, and climate change. The famous wasting disease event of the late 1930s resulted in a widespread loss of eelgrass in this region. Brown tides caused by blooms of the alga Aureococcus anophagefferens in the Long Island area first appeared in 1985 and have also periodically resulted in significant losses of eelgrass. Despite the recent absence of disease and brown tides in some areas, efforts to restore seagrass habitats have had limited to no success. As a result, seagrass habitat generally remains in decline throughout the region. The loss of seagrass may be linked to major declines in both finfish and shellfish populations, cascading to declines in economic and recreational fisheries. Through the Southern New England and New York Seagrass Research Initiative, scientists from The Nature Conservancy and partner institutions are leading research to help revive this critical ecosystem that sustains numerous species and supports our way of life, and to make restoration efforts everywhere a smarter investment.
Southern New England and New York Seagrass Research Towards Restoration – Phase IIWoods Hole Group
April 2014
The second phase of the Seagrass Research and Restoration Initiative evaluated anthropogenic sources of stress to seagrass habitats in Southern New England and New York, in context with site-specific physical characteristics, and studied a series of specific estuaries where restoring enabling conditions will most likely preserve extant seagrass habitat or support recovery of lost habitat. This project focused on: (1) collection of existing data (nutrient loads, flushing rates, water temperature, sediment characteristics, and historical eelgrass distribution), (2) development of decision criteria for the selection of embayments to analyze in further detail, (3) developing additional watershed-estuarine nitrogen load models, and (4) making predictions of future conditions and risks associated with eelgrass preservation and restoration among selected embayments within the study area. This report provides an overview of project goals and objectives, methods applied to calculate nitrogen loads and the prediction of future environmental conditions in a series of selected embayments, and recommendations associated with future efforts to restore seagrass habitat (and the overall functionality of estuarine ecosystems) in the selected embayments.
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The Eelgrass Resource of Southern New England and New York: Science in Support of Management and Restoration Success (Phase I)Short, Fred; Klein, Anita; Burdick, David; Moore, Gregg
June 2012
In this project, genetic and other eelgrass information were investigated to advance both management and restoration science in southern New England and New York coastal waters. The project assessed the genetic diversity of eelgrass across the region and tested it against an experimental factorial design of stress parameters to yield maps of eelgrass distribution and to discover eelgrass populations that are resilient to various stressors that occur regionally. A database of the multiple stressors of eelgrass was created and new information was generated about scientific site selection for eelgrass restoration. The investigators completed an evaluation of eelgrass genetic diversity and population differentiation across the region, detailed geographic studies of eelgrass genetic diversity and resilience, and experimental testing of plant tolerance to multiple stressors in mesocosm experiments. The project contributes to regional eelgrass habitat sustainability through its insights into eelgrass ecology, genetics, and the conditions that affect eelgrass growth, while also yielding information for improved eelgrass restoration. The results of this study provide information on environmental parameters and stressors to eelgrass, information that both improves site selection for restoration and identifies potentially resilient populations of eelgrass with adequate genetic diversity to be used as restoration donor sources.
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