National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science San Juan Island National Historical Park Natural Resource Condition Assessment Natural Resource Report NPS/NRSS/WRD/NRR—xxxx ON THE COVER Looking east from the park, toward Lopez Island and Strait of Juan de Fuca. Photo by Peter Dunwiddie. San Juan Island National Historical Park Natural Resource Condition Assessment Natural Resource Report NPS/NRSS/WRD/NRR—xxx Paul R. Adamus Water Resources Science Program Oregon State University Corvallis, Oregon and Adamus Resource Assessment, Inc. Corvallis, Oregon Peter Dunwiddie University of Washington Seattle, Washington Anna Pakenham Marine Resource Management Program Oregon State University Corvallis, Oregon This report was prepared under Task Agreement P12AC15016 (Cooperative Agreement H8W07110001) between the National Park Service and Oregon State University September 2015 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. 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To receive this report in a format optimized for screen readers, please email [email protected]. Please cite this publication as: Adamus, P. R., P. Dunwiddie, and A. Pakenham. 2015. San Juan Island National Historical Park Natural Resource Condition Assessment. Natural Resource Report NPS/NRSS/WRD/NRR— xxx. National Park Service, Fort Collins, Colorado. NPS xxxx, date xxx ii Contents Page Contents ......................................................................................................................................... iii Figures........................................................................................................................................... vii Tables ........................................................................................................................................... viii Appendices ..................................................................................................................................... ix Executive Summary ........................................................................................................................ x Acknowledgments......................................................................................................................... xii 1.0 NRCA Background ................................................................................................................... 1 2.0 Introduction and Resource Setting ............................................................................................ 4 2.1.1 Enabling Legislation .................................................................................................. 4 2.1.2 Geographic Setting..................................................................................................... 4 2.1.3 Visitation Statistics .................................................................................................... 7 2.2 Natural Resources .............................................................................................................. 8 2.2.1 Ecological Units and Watersheds .............................................................................. 8 2.2.2 Resource Descriptions ............................................................................................... 8 2.2.3 Resource Issues Overview ......................................................................................... 9 2.3 Resource Stewardship ...................................................................................................... 10 2.3.1 Management Directives and Planning Guidance ..................................................... 10 2.3.2 Status of Supporting Science ................................................................................... 10 2.4 Literature Cited ................................................................................................................ 11 3.0 Study Scoping, Design, and Implementation .......................................................................... 13 3.1 Project Responsibilities ................................................................................................... 13 3.2 Study Design .................................................................................................................... 13 3.2.1 Indicator Framework, Focal Study Resources and Indicators ................................. 13 3.2.2 Reporting Areas ....................................................................................................... 14 3.2.3 General Approach and Methods .............................................................................. 14 3.3 Literature Cited ................................................................................................................ 16 Chapter 4. Natural Resource Conditions and Trends ................................................................... 18 iii 4.1 Regional and Local Climate ............................................................................................ 18 4.1.1 Background .............................................................................................................. 18 4.1.2 Regional Context ..................................................................................................... 21 4.1.3 Issues Description .................................................................................................... 21 4.1.4 Data, Methods, and Sources of Expertise ................................................................ 22 4.1.5 Literature Cited ........................................................................................................ 30 4.2 Nearshore Resources ....................................................................................................... 32 4.2.1 Background .............................................................................................................. 32 4.2.2 Regional Context ..................................................................................................... 32 4.2.3 Issues Description .................................................................................................... 34 4.2.3.1 Shoreline Processes and Effects of Artificial Structures ...................................... 34 4.2.3.2 Storm Flooding and Sea Level Rise...................................................................... 36 4.2.3.3 Pollution and Ocean Acidification ........................................................................ 37 4.2.3.4 Marine Debris ....................................................................................................... 39 4.2.3.5 Harvest and Collection of Intertidal Invertebrates ................................................ 39 4.2.4 Data and Methods .................................................................................................... 39 4.2.4.1 Nearshore Water Quality ...................................................................................... 39 4.2.4.2 Eelgrass ................................................................................................................. 40 4.2.4.3 Kelp and Other Nearshore Plants .......................................................................... 42 4.2.4.4 Salmonid Fish