National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Effects of a Storm-Induced Barrier Breach on Community Assemblages and Ecosystem Structure within a Temperate Lagoonal Estuary A Post Hurricane Sandy Analysis Natural Resource Report NPS/NCBN/NRR—2018/1702 ON THE COVER Aerial view of the New Inlet from the south, looking north across Great South Bay, New York on an incoming tide. Photograph courtesy of John Vahey and Charles Flagg, April 18, 2013 Effects of a Storm-Induced Barrier Breach on Community Assemblages and Ecosystem Structure within a Temperate Lagoonal Estuary A Post Hurricane Sandy Analysis Natural Resource Report NPS/NCBN/NRR—2018/1702 Janet A. Nye1, Michael G. Frisk1, Robert M. Cerrato1, Matthew Sclafani2, Charles N. Flagg1, Skyler R. Sagarese3, Jill A. Olin1 1Stony Brook University School of Marine and Atmospheric Sciences Stony Brook, New York 11794 2Cornell University Cooperative Extension 423 Griffing Avenue Riverhead, New York 11777 3NOAA – National Marine Fisheries Service Southeast Fisheries Science Center Miami, Florida 33149 August 2018 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service. The series supports the advancement of science, informed decision-making, and the achievement of the National Park Service mission. The series also provides a forum for presenting more lengthy results that may not be accepted by publications with page limitations. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received formal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This report is available in digital format from the Natural Resource Publications Management website. If you have difficulty accessing information in this publication, particularly if using assistive technology, please email [email protected]. Please cite this publication as: Nye, J. A., M. G. Frisk, R. M. Cerrato, M. Sclafani, C. N. Flagg, S. R. Sagarese, and J. A. Olin. 2018. Effects of a storm-induced barrier breach on community assemblages and ecosystem structure within a temperate lagoonal estuary: A post Hurricane Sandy analysis. Natural Resource Report NPS/NCBN/NRR—2018/1702. National Park Service, Fort Collins, Colorado. NPS 962/147743, August 2018 ii Contents Page Figures.................................................................................................................................................... v Tables ................................................................................................................................................... vii Abstract ................................................................................................................................................. ix Acknowledgments ................................................................................................................................. xi Introduction ............................................................................................................................................ 1 Methods .................................................................................................................................................. 5 Field Surveys .................................................................................................................................. 5 Statistical Analyses ................................................................................................................................ 7 Modeling Physical Regimes ........................................................................................................... 7 Environmental Variables ................................................................................................................ 7 Analysis of Community Metrics and Assemblage Structure .......................................................... 8 Analysis of Species Environmental Preferences ............................................................................ 9 Ecosystem Analysis ...................................................................................................................... 10 Data sources of regional abundance time series used in Ecosim. ........................................... 13 Results .................................................................................................................................................. 15 Environmental Variables .............................................................................................................. 15 Modeling of Circulation and Water Properties............................................................................. 19 Community Metrics ...................................................................................................................... 21 Assemblage Structure ................................................................................................................... 26 Species' Environmental Preference .............................................................................................. 29 Ecosystem-Level Differences ....................................................................................................... 32 Fitted Ecosim Model ............................................................................................................... 32 Network Analysis .................................................................................................................... 36 Model Limitations and Caveats ............................................................................................... 38 Discussion ............................................................................................................................................ 39 Conclusions .......................................................................................................................................... 41 iii Contents (continued) Page Literature Cited .................................................................................................................................... 43 iv Figures Page Figure 1. A) Study area and B) sampling region depicting the major bays (South Oyster Bay, Great South Bay, Bellport Bay, Moriches Bay), tributaries (Carmans River, Connetquot River) and connections to the Atlantic Ocean (Fire Island Inlet and breach location) along the south shore of Long Island, NY. ............................................................................. 2 Figure 2. Distribution of surface salinity (psu) measurements throughout Great South Bay, New York, pre- and post-Sandy. ................................................................................................. 16 Figure 3. Contour maps depicting the seasonal bottom salinity (psu) measurements in Great South Bay, New York, in 2007, 2013, 2014 and 2015 with darkening reds representing a gradient of lower to higher salinities. ........................................................................... 17 Figure 4. Contour maps depicting the seasonal bottom temperature (°C) measurements in Great South Bay, New York, in 2007, 2013, 2014 and 2015 with blues and reds representing a gradient of lower to higher temperatures, respectively. ............................................... 18 Figure 5. Tidal-mean streamlines from the Finite Volume Coastal Ocean Model (FVCOM) showing pre-breach (upper panel) and post-breach (lower panel) under winter conditions in Great South Bay, New York. ......................................................................................... 20 Figure 6. Residence time (in days) before (upper panel) and with (lower panel) the breach in Great South Bay, New York with darker colors representing short turnover and lighter colors representing long turnover. ............................................................................................ 21 Figure 7. Catch composition (% catch per unit effort) from the Great South Bay, New York otter trawl survey by year.. ......................................................................................................... 25 Figure 8. Trends in community composition, A) catch per unit effort (CPUE), B) species richness,