City University of New York (CUNY) CUNY Academic Works All Dissertations, Theses, and Capstone Projects Dissertations, Theses, and Capstone Projects 2-2014 Long-Term Warming And The Size And Phenology Of Long Island Sound Plankton Edward Rice Graduate Center, City University of New York How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/gc_etds/100 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] LONG-TERM WARMING AND THE SIZE AND PHENOLOGY OF LONG ISLAND SOUND PLANKTON By EDWARD JAMES RICE IV A dissertation submitted to the Graduate Faculty in Earth and Environmental Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy, The City University of New York 2014 © 2014 EDWARD JAMES RICE IV All Rights Reserved ii This manuscript has been read and accepted for the Graduate Faculty in Earth and Environmental Science in satisfaction of the dissertation requirement for the degree of Doctor of Philosophy. Prof. Gillian Stewart ____________________________ _________ _______________________________________________ Date Chair of Examining Committee Prof. Cindi Katz___________________________________ _________ ________________________________________________ Date Executive Officer Prof. John Marra ________________________________________________ Dr. Julie Rose ________________________________________________ Prof. John Waldman ________________________________________________ Prof. Gregory O’Mullan ________________________________________________ Supervisory Committee THE CITY UNIVERSITY OF NEW YORK iii Abstract LONG-TERM WARMING SHIFTS THE SIZE AND PHENOLOGY OF LONG ISLAND SOUND ZOOPLANKTON By EDWARD JAMES RICE IV Adviser: Prof. Gillian Stewart In coastal ecosystems with decades of eutrophication and other anthropogenic stressors, the impact of climate change on planktonic communities can be difficult to detect. A time-series of monthly surface water temperatures in the Central Basin of Long Island Sound (LIS) from the late 1940s until 2012 indicates a warming rate of 0.03°C yr-1, with recent summer temperatures increasing most consistently. During this warming trend, the proportion of chlorophyll produced by smaller phytoplankton and flagellates appears to be higher during warmer summer and fall months, enabling an increase in annual chlorophyll despite static nutrient levels. The phenology of phytoplankton and zooplankton abundance also appears to have shifted. Relative to the 1950s, winter and spring chlorophyll blooms are reduced, summer and fall zooplankton size has decreased, the proportion of small zooplankton has increased, and summer zooplankton abundance is reduced. These changes have occurred despite a lack of evidence for increasing gelatinous zooplankton abundance, which has been suggested as a causal mechanism for reduced summer copepod abundance and enhanced summer/fall phytoplankton abundance in other systems that have experienced long-term warming. These changes confirm general predictions for the direct impacts of climate change on aquatic communities, but also highlight the important of indirect impacts due to altered trophic dynamics. iv The author kindly acknowledges the support, patience, and guidance of the following: Prof. Gillian Stewart Dr. Julie Rose Prof. Greg O’Mullan Prof. John Waldman Prof. John Marra Prof. Stephen Baines Prof. Hans Dam Prof. Jeff Bird Matt Lyman Katie O’Brien-Clayton Rodney Randall Kurt Gotschall Robert Alix Werner Schreiner Lydia Norton The NMFS/NOAA Milford Laboratory And my wife: Sarah Garman v Table of Contents • List of Tables………………………………………………………………………………………………viii • List of Figures………………………………………………………………………………………………ix • Introduction……………………………………………………………………………………………….....1 • Chapter 1: Analysis of inter-decadal trends in chlorophyll and temperature in the Central Basin of Long Island Sound. Published by Estuarine, Coastal and Shelf Science, Rice and Stewart, (2013). • Abstract…………………………………………………………………………………………..10 • Introduction………………………………………………………………………………………11 • Methods…………………………………………………………………………………………..13 • Results……………………………………………………………………………………………18 • Discussion………………………………………………………………………………………..28 • Chapter 2: Impact of climate change on estuarine zooplankton: Surface water warming in Long Island Sound is associated with changes in copepod size and community structure. Published by Estuaries and Coasts, Rice et al. (in press) • Abstract…………………………………………………………………………………………..32 • Introduction………………………………………………………………………………………33 • Methods………………………………………………………………………………………….35 • Results…………………………………………………………………………………………...41 • Discussion……………………………………………………………………………………….46 • Chapter 3: Warmer summers in Long Island Sound are associated with a shift in copepod phenology. • Abstract…………………………………………………………………………………………..53 • Introduction………………………………………………………………………………………54 • Methods………………………………………………………………………………………….58 • Results…………………………………………………………………………………………...64 • Discussion……………………………………………………………………………………….71 vi • Thesis Conclusion………………………………………………………………………………………..75 • Appendix …..……………………………………………………………………………………………...84 • Appendix A: Supplementary figures…………………………………………………………..84 • Appendix B: Temperature-induced microbubbles within natural marine samples may inflate small-particle counts in a Coulter Counter. Published 29 Mar 2012, Marine Ecology Progress Series, Rice, Panzeca, and Stewart (2012)………………….............................90 • Bibliography………………………………………………………………………………………………100 vii List of Tables Table Page 1. Historical and current surveys of Central Basin of Long Island Sound (LIS). 15 2. Results of linear regressions for seasonal and annual temperature, Chl a, 22 nutrients and the Chl a/Total Dissolved Nitrogen (TDN) ratio versus time… 3. Statistical significance of environmental variables fitted by Generalized 24 Additive Model (GAM) to Non-metric Multidimensional Scaling (NMDS) ordination of phytoplankton functional groups during summer and fall 2002-8. 4. Annual Calanoid Genus-Richness reported for the Central Basin of LIS….. 47 Differences in mesh size, dates, and number of genera reported are noted. 5. LIS Central Basin zooplankton surveys enumerated by year and mesh size, 65 mean monthly copepod abundance, mean spring copepod abundance, mean summer copepod abundance and total annual copepod abundance………… viii Lists of illustrations, charts, diagrams, etc. Figure Page 1. Map showing historical and current surveys of the Central Basin of LIS……… 14 2. Trends of increasing temperature in degrees Celsius (1975-2010) and Chl a in 18 microgram per liter (1995-2010) compared to historical values (1930-1950s)… 3. Seasonal trends of temperature (1975-2010) from the LIS NOAA Milford Lab... 19 4. Seasonal trend in Chl a (µg l-1) for the Central Basin (1995-2010)…………… 21 5. NMDS plot of phytoplankton groups at summer 2002-8 Connecticut Department 23 of Energy and Environmental Protection (CTDEEP) stations in Central Basin….. 6. NMDS plot of phytoplankton groups, fall CTDEEP Central Basin stations 2002-8. 25 7. Occurrence (by month) and magnitude (in µg l-1) of annual peak in Chl a in the 27 Central Basin for 1952-1958, 1982, and 1993-2010…………………………… 8a. The location of LIS in relation to the Virginian marine biogeographic zone….. 35 8b. The locations of survey and time-series data referenced in this chapter…….. 35 9. Relevant zooplankton surveys in the Central Basin of LIS (1952-2011)………. 37 10A. Inshore Central Basin of LIS trend of temperature (1948-2012)……….……..... 43 10B. LIS temperatures, 1994-2012 and 1952-4 from CTDEEP and Riley et al. (1956). 43 11A. Box and whisker plot of A. tonsa length (µm), 1952 versus 2010-11…………… 44 11B. Box and whisker plot of A. hudsonica length (µm), 1952 versus 2010-11……… 44 12. Mean monthly percentage of Oithona sp. during 1952-1953 and 2010-2011.…. 46 13A. LIS locations and survey stations referenced in this chapter…………………….. 55 13B. Location of the LIS Central basin in relation to US Northeast coastal systems... 55 14A. LIS monthly proportional copepod abundance between 1938 and 1982……….. 66 14B. LIS monthly proportional copepod abundance between 1993 and 2012……….. 66 15A. Copepod abundance observations and predictions, 2002-2004 and 2007-2008… 67 15B. Ctenophore biomass observations and predictions, 2002-2004 and 2007-2008… 67 16. Ctenophore biomass, 2002-2013, at CT DEEP offshore stations H4 and I2…….. 68 17. Ctenophore abundance, 2010-2011, at CT DEEP stations, H2, H4, H6 and I2.... 69 ix 18. Box and whisker plot, Mnemiopsis leidyi clearance rate at 14.6°C and 22.9°C…. 70 19. Central Basin 1991-2011 annual trend in stratification……………………………… 84 20. Principle Components Analysis (PCA) of 1948-2012 temperature trends in LIS… 85 21. Central Basin 1952-4 bi-weekly salinity observations from Riley (1956) versus… 85 CT DEEP Central Basin 1991-2011 mean monthly salinity observations. 22. Nonmetric Multidimensional Scaling (NMDS) of summer zooplankton 2002-2008. 86 23. 1952-4 and 1958-59 surface chlorophyll versus 1994-2011 surface chlorophyll... 87 24A. Surface dissolved oxygen Central Basin LIS 1952-54 versus 1991-2010………… 88 24B. Bottom dissolved oxygen Central Basin LIS 1952-54 versus 1991-2010…………. 88 25. Microscopic images of possible new copepod genera in Central Basin of LIS….. 89 x Introduction: The summary for policy makers of the twelfth session of the Intergovernmental Panel on Climate Change