PEBBLE PROJECT ENVIRONMENTAL BASELINE DOCUMENT 2004 through 2008 CHAPTER 42. MARINE BENTHOS Cook Inlet Drainages PREPARED BY: PENTEC ENVIRONMENTAL, INC. MARINE BENTHOS-COOK INLET DRAINAGES TABLE OF CONTENTS TABLE OF CONTENTS .......................................................................................................................... 42-i LIST OF TABLES .................................................................................................................................. 42-iii LIST OF FIGURES ................................................................................................................................ 42-iv PHOTOGRAPHS ................................................................................................................................... 42-iv LIST OF APPENDICES ......................................................................................................................... 42-iv ACRONYMS AND ABBREVIATIONS ................................................................................................ 42-v 42. MARINE BENTHOS ........................................................................................................................ 42-1 42.1 Introduction ............................................................................................................................. 42-1 42.2 Study Objectives ...................................................................................................................... 42-2 42.3 Study Area ............................................................................................................................... 42-2 42.4 Previous Studies ...................................................................................................................... 42-3 42.4.1 Intertidal Studies ......................................................................................................... 42-3 42.4.1.1 Benthos in Rocky Habitats ....................................................................... 42-4 42.4.1.2 Benthos in Sand/Mud Habitats ................................................................. 42-6 42.4.2 Subtidal Studies .......................................................................................................... 42-6 42.5 Scope of Work ......................................................................................................................... 42-7 42.6 Methods ................................................................................................................................... 42-8 42.6.1 Literature Synthesis .................................................................................................... 42-8 42.6.2 Field Surveys and Collections .................................................................................... 42-8 42.6.2.1 Intertidal Studies ....................................................................................... 42-9 42.6.2.2 Subtidal Benthic Studies ......................................................................... 42-11 42.6.3 Infaunal Data Statistical Analyses ............................................................................ 42-12 42.7 Results and Discussion .......................................................................................................... 42-14 42.7.1 Intertidal Studies ....................................................................................................... 42-14 42.7.1.1 Rocky Intertidal Benthos ........................................................................ 42-14 42.7.1.2 Soft (Gravel, Sand, Mud) Intertidal Benthos .......................................... 42-20 42.7.2 Subtidal Studies ........................................................................................................ 42-26 42.7.2.1 Subtidal Diver Transects ......................................................................... 42-26 42.7.2.2 Subtidal Infauna ...................................................................................... 42-28 42.8 Summary ................................................................................................................................ 42-30 42.8.1 Epibiota ..................................................................................................................... 42-30 42.8.1.1 Intertidal .................................................................................................. 42-30 42.8.1.2 Subtidal ................................................................................................... 42-31 42.8.2 Infauna ...................................................................................................................... 42-32 42.8.2.1 Intertidal .................................................................................................. 42-32 42-i 05/06/2011 PEBBLE PROJECT, ENVIRONMENTAL BASELINE DOCUMENT, 2004 THROUGH 2008 42.8.2.2 Subtidal ................................................................................................... 42-33 42.8.2.3 Infaunal Comparisons ............................................................................. 42-33 42.9 References ............................................................................................................................. 42-34 42.10 Glossary ................................................................................................................................. 42-36 42-ii 05/06/2011 MARINE BENTHOS-COOK INLET DRAINAGES LIST OF TABLES Table 42-1, Infauna Samples from Iniskin and Iliamna Bays, 2004, 2005, and 2008 Table 42-2, Macrobiota at Knoll Head (MPS1), Upper Tidal Elevation, 2006 and 2008 Table 42-3, Macrobiota at Knoll Head (MPS1), Middle Tidal Elevation, 2006 and 2008 Table 42-4, Macrobiota at Knoll Head (MPS1), Lower Tidal Elevation, 2004, 2005, 2006, and 2008 Table 42-5, Macrobiota at Knoll Head West (MPS1A), Upper Tidal Elevation, 2004, 2005, 2006, and 2008 Table 42-6, Macrobiota at Knoll Head West (MPS1A), Middle Tidal Elevation, 2004, 2005, 2006, and 2008 Table 42-7, Macrobiota at Southwest Iniskin Bay (MPS2), Upper Tidal Elevation, 2005 and 2008 Table 42-8, Macrobiota at Southwest Iniskin Bay (MPS2), Middle Tidal Elevation, 2004, 2005, and 2008 Table 42-9, Macrobiota at Diamond Point (MPS3), Upper Tidal Elevation, 2005 and 2008 Table 42-10, Macrobiota at Diamond Point (MPS3), Middle Tidal Elevation, 2004, 2005, and 2008 Table 42-11, Macrobiota at Diamond Point (MPS3), Lower Tidal Elevation, 2004 and 2005 Table 42-12, Macrobiota at North Head (MPS4), Upper Tidal Elevation, 2005 and 2008 Table 42-13, Macrobiota at North Head (MPS4), Middle Tidal Elevation, 2004, 2005, and 2008 Table 42-14, Macrobiota at North Head (MPS4), Lower Tidal Elevation, 2004 and 2005 Table 42-15, Macrobiota at AC Point (MBSA1), Upper Tidal Elevation, 2005 and 2008 Table 42-16, Macrobiota at Scott Island (MSI), Upper Tidal Elevation, 2004, 2005, 2006, and 2008 Table 42-17, Macrobiota at Scott Island (MSI), Middle Tidal Elevation, 2004, 2005, 2006, and 2008 Table 42-18, Macrobiota at Scott Island (MSI), Lower Tidal Elevation, 2004, 2006, and 2008 Table 42-19, Macrobiota at Blackie Beach (MBB), Lower Tidal Elevation, 2004 and 2008 Table 42-20, Ranking of Numerically Dominant Intertidal Macroinfaunal Taxa (first ten) by Average Abundance Table 42-21, Ranking of Dominant Intertidal Macroinfaunal Groups by Average Biomass Table 42-22, Averages of Intertidal Macroinfaunal Measures by Station and Year Table 42-23, Ranking of Dominant Megainfaunal Groups by Average Biomass Table 42-24, Averages of Subtidal Macroinfaunal Measures by Station and Year Table 42-25, Ranking of Numerically Dominant Subtidal Macroinfaunal Taxa (first ten) by Average Abundance Table 42-26, Ranking of Dominant Subtidal Macroinfaunal Groups by Average Biomass 42-iii 05/06/2011 PEBBLE PROJECT, ENVIRONMENTAL BASELINE DOCUMENT, 2004 THROUGH 2008 LIST OF FIGURES Figure 42-1A, Cook Inlet and Kamishak Bay Region Figure 42-1B, Marine Benthos and Nearshore Intertidal and Subtidal Sampling Locations Figure 42-2, Abundance of Major Algal Groups at Scott Island (MSI), 1978 through 2008 Figure 42-3, Abundance of Barnacles (Balanomorpha) and Limpets (Lottiidae) at Scott Island (MSI), 1978 through 2008 Figure 42-4, Abundance of Major Algal Groups at Knoll Head West (MPS1A), 1978 through 2008 Figure 42-5, Abundance of Barnacles (Balanomorpha) and Limpets (Lottiidae) at Knoll Head West (MPS1A), 1978 through 2008 Figure 42-6, Abundance of Major Algal Groups at Knoll Head (MPS1), 1978 through 2008 Figure 42-7, Seasonal Changes in Cover of Major Algal Groups at Scott Island (MSI), April to September 1978 Figure 42-8, Ordination Matrix of Bray-Curtis Similarity Coefficients Calculated for Each Pair of Intertidal Macroinfauna Samples among All Replicates and Stations, 2004 Figure 42-9, Ordination Matrix of Bray-Curtis Similarity Coefficients Calculated for Each Pair of Intertidal Macroinfauna Samples among All Replicates and Stations, 2005 Figure 42-10, Ordination Matrix of Bray-Curtis Similarity Coefficients Calculated for Each Pair of Intertidal Macroinfauna Samples among All Replicates and Stations, 2008 Figure 42-11, Ordination Matrix of Bray-Curtis Similarity Coefficients Calculated for Each Pair of Intertidal Macroinfauna Samples among All Replicates for Those Stations Sampled in All Three Years, 2004, 2005, and 2008 Figure 42-12, Ordination Matrix of Bray-Curtis Similarity Coefficients Calculated for Each Pair of Subtidal Macroinfauna Samples