CHUKCHI SEA ENVIRONMENTAL STUDIES PROGRAM 2008-2010: BENTHIC ECOLOGY OF THE NORTHEASTERN CHUKCHI SEA Prepared for ConocoPhillips Alaska, Inc. P.O. Box 100360 Anchorage, AK 99510-0360 Shell Exploration & Production Company 3601 C Street, Suite 1334 Anchorage, AK 99503 and Statoil USA E & P, Inc. 2700 Gambell St Anchorage, AK 99507 FINAL REPORT Prepared by Arny L. Blanchard Carrie L. Parris Ann L. Knowlton Institute of Marine Science University of Alaska Fairbanks Fairbanks, AK 99775-7220 September 2011 ii TABLE OF CONTENTS List of Figures ..................................................................................................................................v List of Tables ................................................................................................................................ vii Executive Summary ....................................................................................................................... ix 1. General Introduction ....................................................................................................................1 Objectives ..................................................................................................................................3 Methods......................................................................................................................................3 Nomenclature for the 2008-2010 Sampling Cruises ............................................................3 Infauna Sampling Methods ..................................................................................................4 Epifauna Sampling Methods ................................................................................................9 Quality Assurance Procedures .............................................................................................9 References ................................................................................................................................11 2. Benthic Ecology 2010: Association of Infaunal Community Structure with Environmental Variables ............................................................................................................................15 Introduction ..............................................................................................................................15 Methods....................................................................................................................................17 Infauna Sampling Methods ................................................................................................17 Statistical Methods .............................................................................................................19 Results ......................................................................................................................................19 Analysis of the 2008-2010 CSESP Infaunal Data .............................................................19 Discussion ................................................................................................................................37 Benthos of the Klondike, Burger, and Statoil Survey Areas .............................................37 Associations of Fauna with Environmental Characteristics ..............................................39 Temporal Variability ..........................................................................................................41 iii Feeding by Higher Trophic Levels ....................................................................................43 Conclusions ..............................................................................................................................45 Acknowledgements ..................................................................................................................45 References ................................................................................................................................46 3. Benthic Ecology 2010: Association of Epifaunal Community Structure with Environmental Variables ............................................................................................................................53 Introduction ..............................................................................................................................53 Methods....................................................................................................................................55 Epifauna Sampling Methods ..............................................................................................55 Statistical Methods .............................................................................................................57 Results ......................................................................................................................................57 Analysis of the Combined 2009-2010 Epifaunal Data ......................................................57 Discussion ................................................................................................................................73 Epifauna of the Klondike, Burger, and Statoil Study Areas ..............................................73 Spatial Trends and Associations of Fauna with Environmental Characteristics ...............74 Trophic Interactions ...........................................................................................................75 Temporal Trends ................................................................................................................79 Conclusions ..............................................................................................................................80 Acknowledgements ..................................................................................................................80 References ................................................................................................................................81 Appendix I: Statistical Methods for the Analysis of Benthic Data from the Chukchi Sea Environmental Studies Program ........................................................................................87 Appendix II: List of Infaunal Taxa Collected During the 2008-2010 CSESP ..............................95 Appendix III: List of Epifaunal Taxa Collected During the 2009-2010 CSESP .........................109 iv LIST OF FIGURES Figure 1-1. Map of all stations sampled during the 2008-2010 CSESP benthic surveys ...........5 Figure 2-1. Map of stations sampled for infauna during 2008-2010 CSESP surveys ..............18 Figure 2-2. Plots of means and 95% confidence intervals based on the raw data for biological summary measures in survey areas over the 2008-2010 CSESP study .......................................................................................................................23 Figure 2-3. Plots of means and 95% confidence intervals based on the raw data for environmental variables in survey areas over the 2008-2010 CSESP study .........26 Figure 2-4. Plots of means and 95% confidence intervals based on the raw data of the abundance of major taxonomic groups in survey areas over the 2008-2010 CSESP study ..........................................................................................................27 Figure 2-5. Nonmetric multidimensional scaling ordination plot of Bray-Curtis similarities for ln(x+1)-transformed benthic abundance data from 2008- 2010 CSESP sampling ...........................................................................................28 Figure 2-6. Bubble plots of biomass (g m-2) for Amphipoda in Klondike, Burger, and Statoil survey areas collected during 2008-2010 CSESP surveys .........................32 Figure 2-7. Bubble plots of biomass (g m-2) for Bivalvia in Klondike, Burger, and Statoil survey areas collected during 2008-2010 CSESP surveys .........................33 Figure 2-8. Bubble plots of biomass (g m-2) for Gastropoda in Klondike, Burger, and Statoil survey areas collected during 2008-2010 CSESP surveys .........................34 Figure 2-9. Bubble plots of biomass (g m-2) for Polychaeta in Klondike, Burger, and Statoil survey areas collected during 2008-2010 CSESP surveys .........................35 Figure 3-1. Map of stations sampled for epifauna during 2009-2010 CSESP surveys ............56 Figure 3-2. Plots of means and 95% confidence intervals based on the raw data for biological summary measures and environmental variables at survey areas over the 2009-2010 CSESP study ..........................................................................61 Figure 3-3. Plots of means and 95% confidence intervals based on the raw data of the biomass of key taxa at survey areas over the 2009-2010 CSESP study ................63 Figure 3-4. Nonmetric multidimensional scaling ordination plot of Bray-Curtis similarities based on ln(x+1)-transformed epifaunal biomass data, 2009 - 2010 CSESP ...........................................................................................................64 v Figure 3-5. Bubble plots of biomass (g 1000-1 m-2) for brittle stars in the Klondike, Burger, and Statoil survey areas collected during 2009-2010 CSESP ..................67 Figure 3-6. Bubble plots of biomass (g 1000-1 m-2) for crabs in the Klondike, Burger, and Statoil survey areas collected during 2009-2010 CSESP ...............................68 Figure 3-7. Bubble plots of biomass (g 1000-1