NORTH PACIFIC RESEARCH BOARD GULF OF ALASKA INTEGRATED ECOSYSTEM RESEARCH PROGRAM Gulf of Alaska Retrospective Data Analysis NPRB GOA Project Retrospective Component Final Report List of Authors F.J. Mueter1, S.K. Shotwell2, S. Atkinson1, B. Coffin1, M. Doyle3, S. Hinckley4, K. Rand4, J. Waite5 1School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, AK 99801, USA 2Ted Stevens Marine Research Institute, Auke Bay Laboratories, Alaska Fisheries Science Center, National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), 17109 Point Lena Loop Road, Juneau, Alaska, USA, 99801 3Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington, USA 4Alaska Fisheries Science Center, NMFS, NOAA, 7600 Sand Point Way NE, Seattle, Washington, USA 98115 5Division of Wildlife Conservation, Alaska Department of Fish and Game, P.O. Box 110024, Juneau, Alaska, 99801 September 2016 TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................................... 1 GOAIERP PREAMBLE ............................................................................................................................... 2 Program origins ......................................................................................................................................... 2 Program overview ..................................................................................................................................... 2 Rationale ............................................................................................................................................... 2 Hypotheses ............................................................................................................................................ 3 Objectives ............................................................................................................................................. 4 Approach and Research Design ............................................................................................................ 4 Field sampling and process studies ....................................................................................................... 4 Mapping and habitat modeling ............................................................................................................. 6 Laboratory analyses .............................................................................................................................. 6 Retrospective analyses .......................................................................................................................... 6 Modeling ............................................................................................................................................... 6 Program overview- Tables & Figures ....................................................................................................... 7 GENERAL INTRODUCTION ................................................................................................................... 10 Background and Justification .................................................................................................................. 10 Primary Hypotheses and Objectives ....................................................................................................... 11 Approach ................................................................................................................................................. 12 Data compilation ................................................................................................................................. 12 Spatial comparisons ............................................................................................................................ 12 Patterns in atmospheric and oceanographic variability ....................................................................... 12 Patterns in lower trophic level variability ........................................................................................... 18 Variability in larval abundances ......................................................................................................... 18 Recruitment of focal fish species ........................................................................................................ 18 Groundfish community: spatial patterns and trends in focal species and community metrics ........... 18 Seabird and mammal diets .................................................................................................................. 19 Report Organization ................................................................................................................................ 19 CHAPTER 1 - SPATIAL AND TEMPORAL VARIABILITY OF CHLOROPHYLL-A CONCENTRATIONS IN THE COASTAL GULF OF ALASKA, 1998-2011, USING CLOUD-FREE RECONSTRUCTIONS OF SEAWIFS AND MODIS-AQUA DATA ...................................................... 21 Abstract ................................................................................................................................................... 21 Introduction ............................................................................................................................................. 21 Methods .................................................................................................................................................. 23 Results ..................................................................................................................................................... 25 Discussion ............................................................................................................................................... 29 Acknowledgements ................................................................................................................................. 31 ii Literature Cited ....................................................................................................................................... 31 Tables ...................................................................................................................................................... 34 Figures .................................................................................................................................................... 36 CHAPTER 2 - SHARP GRADIENTS IN BIOLOGICAL COMMUNITIES ALONG THE GULF OF ALASKA SHELF ARE ASSOCIATED WITH TOPOGRAPHIC, CLIMATIC AND OCEANOGRAPHIC DISCONTINUITIES ............................................................................................... 47 Introduction ............................................................................................................................................. 47 METHODS ............................................................................................................................................. 48 RESULTS ............................................................................................................................................... 50 Sea-surface temperature ...................................................................................................................... 50 Chlorophyll-a ...................................................................................................................................... 51 Photosynthetically Active Radiation ................................................................................................... 51 Upwelling. ........................................................................................................................................... 51 Groundfish abundance and diversity ................................................................................................... 52 Sensitivity Analyses ............................................................................................................................ 52 Discussion ............................................................................................................................................... 52 Literature cited ........................................................................................................................................ 53 CHAPTER 3 - ENVIRONMENTAL COVARIATES OF SABLEFISH (ANOPLOPOMA FIMBRIA) AND PACIFIC OCEAN PERCH (SEBASTES ALUTUS) RECRUITMENT IN THE GULF OF ALASKA .................................................................................................................................................... 62 Abstract ................................................................................................................................................... 62 Introduction ............................................................................................................................................. 62 Methods .................................................................................................................................................. 67 Results ..................................................................................................................................................... 72 Discussion ..............................................................................................................................................