Draft Environmental Assessment/Analysis of a Marine Geophysical Survey by R/V Marcus G. Langseth of the Cascadia Subduction Zone in the Northeast Pacific Ocean, Late Spring/Summer 2020 Prepared for Lamont-Doherty Earth Observatory 61 Route 9W, P.O. Box 1000 Palisades, NY 10964-8000 and National Science Foundation Division of Ocean Sciences 4201 Wilson Blvd., Suite 725 Arlington, VA 22230 by LGL Ltd., environmental research associates 22 Fisher St., POB 280 King City, Ont. L7B 1A6 21 November 2019 LGL Report FA0186-01A Table of Contents TABLE OF CONTENTS LIST OF FIGURES .......................................................................................................................................... iv LIST OF TABLES ............................................................................................................................................. v ABSTRACT .................................................................................................................................................... vi LIST OF ACRONYMS ..................................................................................................................................... ix I PURPOSE AND NEED ................................................................................................................................... 1 1.1 Mission of NSF ................................................................................................................................ 1 1.2 Purpose of and Need for the Proposed Action ................................................................................. 1 1.3 Background of NSF-funded Marine Seismic Research ................................................................... 2 1.4 Regulatory Setting ........................................................................................................................... 2 II ALTERNATIVES INCLUDING PROPOSED ACTION ...................................................................................... 2 2.1 Proposed Action ............................................................................................................................... 2 2.1.1 Project Objectives and Context ........................................................................................... 2 2.1.2 Proposed Activities ............................................................................................................. 5 2.1.3 Monitoring and Mitigation Measures ................................................................................. 7 2.2 Alternative 1: No Action Alternative ............................................................................................. 10 2.3 Alternatives Considered but Eliminated from Further Analysis .................................................... 10 2.3.1 Alternative E1: Alternative Location ................................................................................ 10 2.3.2 Alternative E2: Use of Alternative Technologies ............................................................. 11 III AFFECTED ENVIRONMENT ..................................................................................................................... 12 3.1 Oceanography ................................................................................................................................ 13 3.2.1 Protected Areas .............................................................................................................................. 14 3.2.1 Critical Habitat in the U.S. ................................................................................................ 14 3.2.2 Critical Habitat in Canada ................................................................................................. 15 3.2.3 Other Conservation Areas in U.S. Waters ........................................................................ 17 3.2.4 Other Conservation Areas in Canada ................................................................................ 18 3.3 Marine Mammals ........................................................................................................................... 20 3.3.1 Mysticetes ......................................................................................................................... 23 3.3.2 Odontocetes ...................................................................................................................... 33 3.3.3 Pinnipeds ........................................................................................................................... 44 3.3.4 Fissiped 50 3.4 Sea Turtles ..................................................................................................................................... 51 3.4.1 Leatherback Turtle (Dermochelys coriacea) .................................................................... 51 3.4.2 Green Turtle (Chelonia mydas) ........................................................................................ 53 3.5 Seabirds .......................................................................................................................................... 53 3.5.1 Short-tailed Albatross ....................................................................................................... 54 3.5.2 Hawaiian Petrel ................................................................................................................. 55 3.5.3 Marbled Murrelet .............................................................................................................. 55 3.5.4 Pink-footed Shearwater ..................................................................................................... 56 Draft Environmental Assessment/Analysis for L-DEO Cascadia Subduction Zone, 2020 Page ii Table of Contents 3.5.5 Tufted Puffin ..................................................................................................................... 56 3.6 Fish and Marine Invertebrates, Essential Fish Habitat, and Habitat Areas of Particular Concern 56 3.6.1 ESA-Listed Fish Species .................................................................................................. 56 3.6.2 Essential Fish Habitat ....................................................................................................... 59 3.6.3 Habitat Areas of Particular Concern ................................................................................. 61 3.6.4 SARA-Listed Fish and Marine Invertebrate Species ........................................................ 63 3.6.5 Rockfish Conservation Areas ........................................................................................... 65 3.7 Fisheries ......................................................................................................................................... 65 3.7.1 Commercial Fisheries ....................................................................................................... 65 3.7.2 Recreational Fisheries ....................................................................................................... 65 3.7.3 Subsistence Fisheries ........................................................................................................ 67 3.8 Aquaculture .................................................................................................................................... 67 3.9 Shipwrecks and SCUBA Diving .................................................................................................... 68 IV ENVIRONMENTAL CONSEQUENCES ....................................................................................................... 69 4.1 Proposed Action ............................................................................................................................. 69 4.1.1 Direct Effects on Marine Mammals and Sea Turtles and Their Significance ................... 69 4.1.2 Direct Effects on Marine Invertebrates, Fish, and Fisheries, and Their Significance....... 90 4.1.3 Direct Effects on Seabirds and Their Significance ........................................................... 97 4.1.4 Indirect Effects on Marine Mammals, Sea Turtles, Seabirds and Fish and Their Significance ...................................................................................................................... 98 4.1.5 Direct Effects on Cultural Resources and Their Significance .......................................... 98 4.1.6 Cumulative Effects ........................................................................................................... 98 4.1.7 Unavoidable Impacts ...................................................................................................... 103 4.1.8 Coordination with Other Agencies and Processes .......................................................... 103 4.2 No Action Alternative .................................................................................................................. 103 V LIST OF PREPARERS .............................................................................................................................. 105 VI LITERATURE CITED ............................................................................................................................. 106 LIST OF APPENDICES ................................................................................................................................. 163 APPENDIX A: DETERMINATION OF MITIGATION ZONES .........................................................................