2006 Progress Report: Thresholds And Multiple Stable States In Southern New England Shallow Water Estuarine Communties

EPA Grant Number: R832448
Title: Thresholds And Multiple Stable States In Southern New England Shallow Water Estuarine Communties
Investigators: Osman, Richard W. , Whitlatch, Robert B. , Zajac, Roman N.
Institution: Smithsonian Environmental Research Center
EPA Project Officer: Hiscock, Michael
Project Period: September 1, 2005 through August 31, 2007 (Extended to August 31, 2008)
Project Period Covered by this Report: September 1, 2005 through August 31, 2006
Project Amount: $299,694
RFA: Exploratory Research: Understanding Ecological Thresholds In Aquatic Systems Through Retrospective Analysis (2004) RFA Text |  Recipients Lists
Research Category: Aquatic Ecosystems , Ecosystems , Water

Objective:

We are using a number of different modeling approaches to investigate threshold dynamics in a representative set of shallow-water communities of the southern New England region. Our goal is to determine how the distribution of distinct, easily-recognized alternate communities can be used to develop and measure the success of management decisions on local to regional scales. The main system is the Long Island Sound (LIS) estuary and its complex system of multiple habitats, sub-estuaries and rivers with multiple land uses and environmental stresses, both natural and anthropogenic. This system has a diverse set of management concerns that span site-specific to habitat to regional in scale. We are focusing on the diverse set of benthic invertebrate communities that are integral to multiple habitats within LIS, have diversity of species and life-histories, and exist in at least four known community states. Our modeling is directed at the transitions among these communities. The two main objectives are:

  1. To use existing data to first examine the potential global, regional, and local processes that cause switches among threshold states of the communities in LIS and under what conditions these states remain resilient and unchanged.
  2. To contrast and evaluate adaptive management strategies for this system in the face of climate change.

Progress Summary:

In Year 1 we have concentrated on Objective 1, the developing and testing the necessary models for examining the processes contributing to thresholds as well as causing shifts among alternate threshold states. To date we have:

  • Conducted an initial mini-workshop in early 2006 for the principal investigators to develop overall approaches and responsibilities for modeling.
  • Made the addition of a post-doctoral fellow responsible for population and community modeling and model integration. An international search was conducted and Dr. Pablo Mungia joined the project in the summer of 2006.
  • Begun the critical assembling, cataloguing, and standardization of all data critical to model development and testing. Because different types of models are being applied under the direction of different investigators it is essential that the same biological, ecological, geographic, and environmental data are being utilized in all modeling efforts.
  • Developed a set of defined threshold characteristics that can be used in evaluating models. It is critical to define a priori what model outputs will be interpreted as system resilience and threshold states as well as what changes will be interpreted as a breakdown in a threshold, the absence of threshold behavior, or the transition to a new threshold state. The degree of variability that can be accommodated as part of any stable state also needs to be defined.
  • Held a two day project evaluation and planning workshop at SERC in August 2006. Principal investigators and postdoctoral fellows involved in the project participated. Goals and responsibilities for the next phase of the project were discussed and particular attention was given to integration of the different modeling efforts.
  • Begun developing and testing simpler population and community models using Matlab. This research is the focus of Dr. Mungia.
  • Modifying and expanding the spatially-explicit, hydrographic model developed by Dr. John Hamilton, a postdoctoral fellow with Dr. Whitlatch. This model has been expanded to examine a larger geographic area, to include a greater diversity of species life-history characteristics that encompass the key threshold species and communities, and to encompass defined threshold states.
  • Begun development of project geographic information system (GIS), including the assembly and verification of base layers, e.g. land use, infrastructure, shoreline, coastal features, bathymetry. Currently we are adding environmental data that will be critical for developing GIS based threshold models.
  • Developed methods to integrate models and define overlapping scales for models. A key element to the integration of the qualitative, population, community, spatially-explicit hydrographic, and geographic models is the overlap among model types in the questions and issues they address as well as their having comparable output.
  • Have begun integrating new information on a new invader in the region, the colonial ascidian, Didemnum sp. The recent invasion of this species has the potential to change threshold states or, possibly add a new state to the system being modeled. Other projects being conducted by several of the principal investigators are addressing the ecology of this species and these data are being integrated into the modeling efforts. Including this species is particularly important because of its potential effects on deeper water and open coast habitats not usually impacted by the other invasive species. Because the management issues may be quite different for this species its inclusion will both address these issues and test the broader applicability of the models.

Future Activities:

Present modeling efforts and model integration will continue and be expanded. It is anticipated that as simpler models are tested and validated they will be expanded in complexity in order that they can be adapted to address the broadest array of management questions. We will also continue to update and integrate new data and re-evaluate models. Activities planned include:

  • A workshop in early 2007 to evaluate progress, actively contrast and integrate various modeling efforts, and develop a linked strategy for applying the models to management issues and scenarios.
  • Develop GIS based threshold models and integrate the results of the other modeling efforts into the project GIS model. Products from these efforts will provide mapping at multiple scales as to the spatial characteristics of modeling results along the coastal regions we are studying.
  • The presentation of results at one or more international scientific meetings. At least two presentations are being prepared for the Benthic Ecology Meetings in Atlanta, GA.
  • Develop and add specific project pages to existing web sites (see below). The pages will present results of the project and allow interaction between the principal investigators and managers regarding model applications.
  • Publication of the models and modeling results. Initial publications are planned for at least two of the modeling approaches. Future publication of model integration and applications are also planned.
  • Make one or more presentations of model applications to local or regional managers. This may be done as a small forum or as a one-day workshop.
  • Presentation of the threshold concept, implications, and applications to resource management and environmental concerns to the general public. This will be done through normal outreach activities of the principal investigators.


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 34 publications 8 publications in selected types All 8 journal articles
Type Citation Project Document Sources
Journal Article Altman S, Whitlatch RB. Effects of small-scale disturbance on invasion success in marine communities. Journal of Experimental Marine Biology and Ecology 2007;342(1):15-29. R832448 (2006)
R832448 (2007)
R832448 (Final)
R830877 (Final)
  • Full-text: Science Direct Full Text
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  • Abstract: Science Direct Abstract
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  • Other: Science Direct PDF
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  • Journal Article Bullard SG, Lambert G, Carman MR, Byrnes J, Whitlatch RB, Ruiz G, Miller RJ, Harris L, Valentine PC, Collie JS, Pederson J, McNaught DC, Cohen AN, Asch RG, Dijkstra J, Heinonen K. The colonial ascidian Didemnum sp. A:current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America. Journal of Experimental Marine Biology and Ecology 2007;342(1):99-108. R832448 (2006)
    R832448 (2007)
    R832448 (Final)
    R830877 (Final)
  • Full-text: Science Direct
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  • Abstract: Science Direct Abstract
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  • Other: Science Direct PDF
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  • Journal Article McCarthy A, Osman RW, Whitlatch RB. Effects of temperature on growth rates of colonial ascidians: a comparison of Didemnum sp. to Botryllus schlosseri and Botrylloides violaceus. Journal of Experimental Marine Biology and Ecology 2007;342(1):172-174. R832448 (2006)
    R832448 (2007)
    R832448 (Final)
    R830877 (Final)
  • Full-text: Science Direct Full Text
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  • Abstract: Science Direct Abstract
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  • Other: Science Direct PDF
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  • Journal Article Osman RW, Whitlatch RB. Variation in the ability of Didemnum sp. to invade established communities. Journal of Experimental Marine Biology and Ecology 2007;342(1):40-53. R832448 (2006)
    R832448 (2007)
    R832448 (Final)
    R830877 (2005)
    R830877 (Final)
  • Full-text: Science Direct Full Text
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  • Abstract: Science Direct Abstract
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  • Other: Science Direct PDF
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  • Supplemental Keywords:

    Ecological thresholds, multiple stable states, global climate, marine, estuary, ecological effects, ecosystem indicators, ecology, modeling, northeast,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, climate change, Air Pollution Effects, Aquatic Ecosystem, Environmental Monitoring, Ecology and Ecosystems, Ecological Risk Assessment, Atmosphere, anthropogenic stress, estuarine research, ecological thresholds, anthropogenic impact, ecosystem indicators, modeling ecosystem change, aquatic ecosystems, water quality, ecosystem stress, riverine ecosystems, trophic interactions, ecosystem response

    Relevant Websites:

    http://www.serc.si.edu/labs/benthic_ecology/index.jsp Exit
    http://www.marinesciences.uconn.edu/teamb/Pages/Team%20Benthos.htm Exit
    http://newton.newhaven.edu/rzajac/index.html Exit

    Progress and Final Reports:

    Original Abstract
  • 2007 Progress Report
  • Final Report