U.S. Fish & Wildlife Service HABITAT MANAGEMENT PLAN FOR DELTA AND BRETON NATIONAL WILDLIFE REFUGES Plaquemines and St. Bernard Parishes, Louisiana Southeast Region Delta and Breton National Wildlife Refuge Habitat Management Plan U.S. Department of the Interior Fish and Wildlife Service Southeast Region August 2013 Table Of Contents HABITAT MANAGEMENT PLAN I. Introduction ...........................................................................................................................1 Scope and Rationale .......................................................................................................3 Legal Mandates ...............................................................................................................5 Relationship To Other Plans ............................................................................................5 International, National, and Regional Plans..........................................................6 Local and State Plans ..........................................................................................8 II. Environmental Setting and Background ...........................................................................11 Location .........................................................................................................................11 Habitat Types and Descriptions .....................................................................................11 Delta NWR .........................................................................................................11 Breton NWR .......................................................................................................11 Physical and Geographic Setting ...................................................................................25 Climate ..............................................................................................................25 Air Quality ..........................................................................................................27 Geomorphology and Topography .......................................................................27 Hydrology...........................................................................................................28 Soils ...................................................................................................................28 Subsidence and Sea Level Rise ........................................................................30 Flyways ..............................................................................................................31 History of Refuge Lands ................................................................................................33 Historic Habitat Conditions .................................................................................33 Prehistoric Habitat Conditions ............................................................................34 Current Habitat Conditions .................................................................................34 Changes in Habitat Conditions ...........................................................................34 III. Resources of Concern .......................................................................................................36 Identification of Resources of Concern ..........................................................................36 Descriptions of Resources of Concern...........................................................................37 Waterfowl ...........................................................................................................37 Shorebirds .........................................................................................................39 Secretive marsh birds ........................................................................................41 Colonial breeding wading birds ..........................................................................43 Table of Contents i Brown pelicans ..................................................................................................44 Gulls and terns ...................................................................................................46 Habitat Requirements of Resources of Concern ............................................................49 Waterfowl ...........................................................................................................49 Shorebirds .........................................................................................................51 Secretive marsh birds ........................................................................................52 Colonial breeding wading birds ..........................................................................56 Brown Pelican ....................................................................................................56 Gulls and Terns..................................................................................................57 Refuge Contribution to Habitat Needs of Resources of Concern ........................58 IV. Habitat Management Goals and Objectives .....................................................................60 A. Delta NWR Habitat Management: Emergent Marsh ................................................61 Objective A-1: Emergent Marsh Protection .......................................................61 Objective A-2: Emergent Marsh Restoration .....................................................62 Objective A-3: Emergent Marsh Management ...................................................62 B. Breton NWR Habitat Restoration: Barrier Island Habitat ..........................................63 Objective B-1: Island Restoration ......................................................................63 Objective B-2: Dune Restoration .......................................................................64 C. Breton NWR Wilderness ..........................................................................................65 Objective C-1: Wilderness Protection ................................................................66 V. Habitat Management Strategies .........................................................................................68 Emergent Marsh Protection Strategies for Delta NWR ..................................................68 Potential Strategies ............................................................................................68 Strategy Prescription ..........................................................................................68 Emergent Marsh Restoration Strategies for Delta NWR ................................................68 Potential Strategies ............................................................................................68 Strategy Prescription ..........................................................................................69 Research Strategies ......................................................................................................69 Potential Strategies ............................................................................................69 Strategy Prescription ..........................................................................................69 Island Restoration (Breton NWR) ..................................................................................69 Potential Strategies ............................................................................................69 Strategy Prescription ..........................................................................................70 Dune Restoration Strategy (Breton NWR) .....................................................................70 ii Delta and Breton National Wildlife Refuges Potential Strategies ............................................................................................70 Strategy Prescription ..........................................................................................71 Wilderness Protection Strategy (Breton NWR) ..............................................................71 Potential Strategies ............................................................................................71 Strategy Prescription ..........................................................................................73 Partnership Strategies ...................................................................................................73 Potential Strategies ............................................................................................73 Strategy Prescription ..........................................................................................73 Monitoring Strategies .....................................................................................................74 Potential Strategies ............................................................................................74 Management Strategy Prescription ....................................................................74 Undesirable Species Management Strategies ...............................................................74 Potential Strategies ............................................................................................75 Management Strategy Prescription ....................................................................75 Inviolate Sanctuary Strategies .......................................................................................76 Potential Strategies