New England Fishery Management Council 50 WATER STREET | NEWBURYPORT, MASSACHUSETTS 01950 | PHONE 978 465 0492 | FAX 978 465 3116 E.F. “Terry” Stockwell III, Chairman | Thomas A. Nies, Executive Director OMNIBUS ESSENTIAL FISH HABITAT (EFH) AMENDMENT 2 DRAFT ENVIRONMENTAL IMPACT STATEMENT Appendix D: The Swept Area Seabed Impact (SASI) approach: a tool for analyzing the effects of fishing on Essential Fish Habitat Appendix D: The Swept Area Seabed Impact Approach This document was prepared by the following members of the NEFMC Habitat Plan Development team, with feedback from the NEFMC Habitat Oversight Committee, NEFMC Habitat Advisory Panel, and interested members of the public. Michelle Bachman, NEFMC staff Peter Auster, University of Connecticut Chad Demarest, NOAA/Northeast Fisheries Science Center Steve Eayrs, Gulf of Maine Research Institute Kathyrn Ford, Massachusetts Division of Marine Fisheries Jon Grabowski, Gulf of Maine Research Institute Brad Harris, University of Massachusetts School of Marine Science and Technology Tom Hoff, Mid-Atlantic Fishery Management Council Mark Lazzari, Maine Department of Marine Resources Vincent Malkoski, Massachusetts Division of Marine Fisheries Dave Packer, NOAA/ Northeast Fisheries Science Center David Stevenson, NOAA/Northeast Regional Office Page Valentine, U.S. Geological Survey January 2011 Page 2 of 257 Appendix D: The Swept Area Seabed Impact Approach Table of Contents 1.0 OVERVIEW OF THE SWEPT AREA SEABED IMPACT MODEL ........... 13 2.0 DEFINING HABITAT ....................................................................................... 18 2.1 Geological habitat component ................................................................................... 20 2.1.1 Sediments, surface and subsurface .................................................................... 20 2.1.2 Biogenic depressions and burrows .................................................................... 20 2.1.3 Bedforms ................................................................................................................ 21 2.1.4 Gravel and gravel pavements ............................................................................. 21 2.1.5 Cobble and boulder piles ..................................................................................... 22 2.1.6 Shell deposits ......................................................................................................... 22 2.2 Biological habitat component ..................................................................................... 22 2.2.1 Amphipods – tube-dwelling ............................................................................... 23 2.2.2 Anemones – actinarian and cerianthid .............................................................. 24 2.2.3 Ascidians ................................................................................................................ 26 2.2.4 Brachiopods ........................................................................................................... 27 2.2.5 Bryozoans ............................................................................................................... 28 2.2.6 Sea pens .................................................................................................................. 30 2.2.7 Hydroids ................................................................................................................ 31 2.2.8 Macroalgae ............................................................................................................. 34 2.2.9 Mollusks, epifaunal bivalve ................................................................................ 37 2.2.10 Polychaetes – tube-dwelling................................................................................ 38 2.2.11 Sponges .................................................................................................................. 40 3.0 FISHING GEARS EVALUTED ........................................................................ 43 3.1 Demersal otter trawls .................................................................................................. 52 3.1.1 Generic otter trawls (including groundfish and scallop trawls) .................... 53 3.1.2 Shrimp trawls ........................................................................................................ 54 3.1.3 Squid trawls ........................................................................................................... 55 3.1.4 Raised footrope trawls ......................................................................................... 55 3.2 New Bedford-style scallop dredges .......................................................................... 55 3.3 Hydraulic clam dredges .............................................................................................. 56 3.4 Demersal longlines ...................................................................................................... 56 3.5 Sink gill nets .................................................................................................................. 57 3.6 Traps .............................................................................................................................. 58 4.0 GEAR IMPACTS LITERATURE REVIEW .................................................... 60 4.1 Methods: database and coding .................................................................................. 60 4.2 Tabular summary of literature ................................................................................... 65 5.0 ESTIMATING SUSCEPTIBILITY AND RECOVERY FOR BIOLOGICAL AND GEOLOGICAL FEATURES ............................................................................. 91 5.1 Methods: S-R matrices ................................................................................................. 91 5.2 Results: S-R matrices.................................................................................................... 95 5.2.1 Demersal otter trawls ........................................................................................... 95 5.2.2 New Bedford-style scallop dredge ................................................................... 102 January 2011 Page 3 of 257 Appendix D: The Swept Area Seabed Impact Approach 5.2.3 Hydraulic clam dredges ..................................................................................... 107 5.2.4 Fixed gears ........................................................................................................... 110 5.2.4.1 Demersal longline and sink gillnet .......................................................... 110 5.2.4.2 Lobster and deep-sea red crab traps ....................................................... 112 5.2.4.3 Fixed gear susceptibility summary .......................................................... 115 5.2.5 Recovery– all gear types .................................................................................... 117 5.2.6 Summary of vulnerability assessment results ................................................ 125 5.3 Discussion ................................................................................................................... 133 5.3.1 Literature review ................................................................................................ 134 5.3.2 Susceptibility ....................................................................................................... 135 5.3.3 Recovery ............................................................................................................... 136 5.3.4 Potential sources of bias in the Vulnerability Assessment ........................... 136 6.0 ESTIMATING CONTACT-ADJUSTED AREA SWEPT ........................... 138 6.1 Area swept model specification ............................................................................... 138 6.1.1 Demersal otter trawl ........................................................................................... 139 6.1.2 New Bedford-style scallop dredge ................................................................... 141 6.1.3 Hydraulic clam dredge ...................................................................................... 141 6.1.4 Demersal longline and sink gillnet ................................................................... 142 6.1.5 Lobster and deep-sea red crab traps ................................................................ 143 6.2 Data and parameterization ....................................................................................... 144 6.2.1 Demersal otter trawl ........................................................................................... 144 6.2.2 New Bedford-style scallop dredge ................................................................... 149 6.2.3 Hydraulic clam dredge ...................................................................................... 150 6.2.4 Demersal longline ............................................................................................... 151 6.2.5 Sink gillnet ........................................................................................................... 151 6.2.6 Traps ..................................................................................................................... 151 7.0 DEFINING HABITATS SPATIALLY ........................................................... 152 7.1 Substrate data and unstructured grid ....................................................................