COASTAL IMPOUNDMENT DECISION MAKING ADAPTATION IN ACTION Rob Hossler and Karen Bennett – Delaware Div. Fish & Wildlife Austin Kane - National Wildlife Federation LIONS, TIGERS and On The GROUND CLIMATE CHANGE ADAPTATION… OH MY! Delaware’s Efforts to get over the Fear and Make Decisions to Implement/Adapt to Climate Change for its Coastal Impoundments Coastal Impoundments History Salt hay farming Rice production Waterfowl habitat Mosquito control Today…Multiple Functions for Wildlife: Breeding habitat for shorebirds, rails, bitterns, waterfowl Roosting habitat for shorebirds, waterfowl Feeding habitat for migrating shorebirds, waterfowl, postbreeding wading birds Fish nursery habitat Muskrat habitat Today…Multiple Socioeconomic Functions: Waterfowl hunting Birding, wildlife viewing, photography Furbearer trapping Flood-hazard reduction Mosquito control Coastal Impoundments in DE: • State maintains 14 coastal impoundments comprising 2,400 acres on several state wildlife areas along the central to southern Delaware Bay coast, and a few along the Atlantic Coast. • USFWS maintains 1,100 acres at Bombay Hook NWR and 4,200 acres at Prime Hook NWR, both along Delaware Bay coast. Urgency to Do Adaptation Thrust Upon Us Breaches 2010 Breaches 2012 Impoundment Wetland Habitat at risk Impoundment wetlands converting to open water. Prime Hook NWR – after Hurricane Sandy 2012. Prime Hook NWR – after 2009 Mother’s Day storm. STATE IMPOUNDMENTS ARE NOT IMMUNE! Breach of State Impoundment Dikes after Hurricane Irene (2011) Step 1: Initiation of a State Impoundment Management Plan/Philosophy • Collective wisdom of administrator, program and land managers, and staff scientists to support continued management and preservation of state impoundments. • Goal is to Avoided Administrative Neglect, i.e., “I will be retired before it’s an issue” and make adaptation an immediate priority among other current funding needs. • Begin the development of a systematic approach for evaluating the current status of impoundments, identifying objectives and developing an adaptive strategy to enhance resilience in face of climate change. Multiple OBJECTIVES: • Maximize Juvenile Fish Populations • Maximize Breeding Marsh • Maintain Furbearer Birds populations at a desired level • Maximize Roosting Red (e.g., Muskrat) Knots and Spring • Minimize Mosquito Production Migrating Shorebirds • Maximize Recreational Use • Maximize Breeding • Minimize Cost Shorebirds (e.g., Blacknecked Stilt) • Maximize Migrating and Wintering Waterfowl • Maximize Fall Migrating Shorebirds • Maximize Breeding Waterfowl Now what??? It’s complicated…. • We can’t manage for everything, everywhere…not physically possible given biological needs of target wildlife. • We’ll never have all the data we think we need. • Cost constraints and uncertainty are a reality. • Tradeoffs among competing objectives must be made. • We want to find the best combination of management actions to achieve multiple affordable objectives in the face of climate change uncertainty. Step 2: Approach - Structured Decision Making • Developed a prototype decision model for 4 impoundments looking 30 years out (estimated impoundment life span). • Small team of experts identified key management objectives and predicted outcomes (e.g., duck-use days, roosting red knots, mosquito and fish counts) of different actions under different SLR scenarios (5 and 10 mm/year). • SDM is an explicit, organized way to deal with multiple, competing objectives and uncertainty. • Flexible • Incorporates cost constraints • Transparent • Provides a suite of actions that maximizes benefit • Adaptive GOAL: If we are spending the time and money on these impoundments we need to maximize their functions in an explicit, organized way that deals with multiple, competing management objectives and cost constraints under the uncertainty of SLR. Coordinated water-level management (% of full pool) across a suite of impoundments to provide for: Vegetation growth (waterfowl) Exposed mudflat (shorebirds) Pools and channels (fish and mosquitos) Annual Drawdown Actions 120 % of Full Pool 100 80 MOSQ REKN 60 WF Es.Fish 40 DE Saline 20 0 Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Influences – Consequences Diagram Predator Control Water Mgmt Vegetation Control Stopover Population Predators Water Level Amt. Roost Habitat Roosting Red Knots Habitat Configuration Tide Weather Distance to Foraging Habitat Climate Change Rectangles = management decision nodes; ovals = stochastic process nodes; rounded rectangles = intermediate calculations; and hexagons = outcomes (e.g., objectives). Utility Functions for Objectives (b) Red Knot (c) Fish 1.0 1 0.9 0.9 0.9 0.8 0.8 0.8 0.7 0.7 0.7 0.6 0.6 0.6 0.5 0.4 Value 1.0 Value Value (a) Waterfowl 0.5 0.4 0.5 0.4 0.3 0.3 0.3 0.2 0.2 0.2 0.1 0.1 0.1 0.0 0.0 0 10000 20000 Waterfowl Abundance Score 30000 0 0 500 1000 Red Knot Abundance Score 0 1 2 3 4 Fish Score These objectives were than weighted for Relative Importance. Example - Red Knots = 0.31 Waterfowl = 0.38 Fish = 0.17 Mosquito = 0.14 5 LONG-TERM ACTIONS UNDER SLR UNCERTAINTY: Water management regime? Repair levees and water-control structures? Raise elevation with thin-layer application of dredge material? Create salt marsh buffers? Build new impoundments in uplands? Abandon and restore to tidal salt marsh habitat? Consequences – Predictions and UncertaintyUncertaint Uncertainty y Impoundment Action Plan Sea Level Δ Base Cost (k) Add. Cost (k) REKN 10yr REKN 20yr REKN 30yr Primehook - Unit 3 Action 1 ("WF") Accelerated Rate 22.5 na 75 50 0 Primehook - Unit 3 Action 1 ("WF") Current Rate 22.5 na 100 75 50 Primehook - Unit 3 Action 2 ("REKN") Accelerated Rate 15 na 225 150 0 Primehook - Unit 3 Action 2 ("REKN") Current Rate 15 na 300 225 150 Primehook - Unit 3 Action 3 ("DE Saline") Accelerated Rate 10 na 50 0 0 Primehook - Unit 3 Action 3 ("DE Saline") Current Rate 10 na 50 50 15 Primehook - Unit 3 Act.4: Raise levee, replace WCS +WF Accelerated Rate 22.5 1200 100 75 50 Primehook - Unit 3 Act.4: Raise levee, replace WCS +WF Current Rate 22.5 1200 100 100 100 Primehook - Unit 3 Act.5: Raise levee, replace WCS +REKN Accelerated Rate 15 1200 300 235 150 Primehook - Unit 3 Act.5: Raise levee, replace WCS +REKN Current Rate 15 1200 300 300 300 Primehook - Unit 3 Act.6: Raise levee, replace WCS +DNREC Accelerated Rate 10 1200 50 40 25 Primehook - Unit 3 Act.6: Raise levee, replace WCS +DNREC Current Rate 10 1200 50 50 50 How Do We Decide? • Each action has an expected benefit. • Benefit is determined by: – Species response – Uncertainty – Species weighting • Each action has a cost. Using Excel “Solver” Add-in: Mgt. Unit Unit III PH Unit III PH Unit III PH Unit III PH Unit III PH Unit III PH Raymond Raymond Raymond Raymond Raymond LoganS LoganS LoganS LoganS LoganS LoganS LittleCrk LittleCrk LittleCrk LittleCrk LittleCrk LittleCrk Management Action WEV Waterfowl WEV Knots WEV Fish A1: Waterfowl water regime 0.3619 0.1234 0.1255 A2: Red Knot water regime 0.2744 0.1623 0.1255 A3 DE Saline water regime 0.1269 0.0269 0.1255 A4: Raise levee, replace wcs, & (A1) 0.6494 0.0748 0.1255 A5: Raise levee, replace wcs, & (A2) 0.2996 0.2251 0.1255 A6: Raise levee, replace wcs, & (A3) 0.2177 0.0376 0.1255 A1: Waterfowl water regime 0.0369 0.0000 0.0000 A2: Red Knot water regime 0.0191 0.0402 0.0000 A3: DE Saline water regime 0.0126 0.0000 0.0000 A4: Raise wcs @ 20 yrs, & (A1) 0.0382 0.0000 0.0000 A5: Raise wcs @ 20 yrs, & (A2) 0.0191 0.0402 0.0000 A1: Waterfowl water regime 0.0217 0.2688 0.0983 A2: Red Knot water regime 0.0209 0.4159 0.0988 A3: DE Saline water regime 0.0152 0.0021 0.2234 A4: Construct new 150 ac imp, pumping, & (A1) 0.0756 0.2812 0.0072 A5: Construct new 150 ac imp, pumping, & (A2) 0.0442 0.3239 0.0072 A6: Construct new 150 ac imp, pumping, & (A3) 0.0415 0.0000 0.0072 A1:Waterfowl water regime 0.0163 0.2776 0.0588 A2: Red Knot water regime 0.0119 0.4226 0.0588 A3: DE Saline water regime 0.0082 0.0000 0.4382 A4: Replace wcs, dike work, sediment control, & (A1) 0.0191 0.3739 0.0308 A5: Replace wcs, dike work, sediment control, & (A2) 0.0137 0.5610 0.0308 A6: Replace wcs, dike work, sediment control, & (A3) 0.0087 0.0000 0.4396 Portfolio 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 1 0 0 0 0 Management Benefit Cost ($K) 0.6108 $23 0.5622 $15 0.2793 $10 0.8497 $1,200 0.6501 $1,200 0.3807 $1,200 0.0369 $2 0.0593 $2 0.0126 $1 0.0382 $200 0.0593 $200 0.3887 $10 0.5355 $10 0.2406 $13 0.3640 $700 0.3752 $700 0.0487 $700 0.3527 $5 0.4933 $5 0.4465 $7 0.4239 $800 0.6055 $800 0.4484 $800 1.6989 $238 1.6989 Waterfowl 0.4138 Red Knot 1.0021 Fish 0.2831 Cost Constraint $250 Step 3: Pilot Habitat Projects • Select “no regret” restoration projects anticipated to have success to restore wetland habitat and enhance impoundment resiliency to climate change. • These project fall in three categories: Better Management Practices Resiliency in the Form of Structure Integrity (improvements or buffers). Strategic Retreat. Better Management Practices • Better Data Collection: Vegetation Transects, Integrated Waterbird Management and Monitoring (“IWMM”), Hydrology and Hydraulic studies. • Are we achieving what we want – qualitatively and quantitatively? • Provides baseline for monitoring of pilot projects, SLR scenarios and evaluating management practices. Buffer Construction Restore old levee Create tidal marsh within 106-acre containment cell, eventually with tidal exchange via channel creation. Reinforce existing dikes Strategic Retreat • Wildlife Conservation Societyfunded project working with The National Wildlife Federation. • Inland retreat of a 389-acre impoundment where we have lost some of our management capabilities to maximize functions and values. • Creates an 86-acre impoundment complex from an existing pond and two agricultural fields augmented with freshwater to maximizes functions and values and replace larger impoundment. Thank you!!! • National Fish and Wildlife Foundation • Wildlife Conservation Society • State Wildlife Grants and Wildlife and Sport Fish Restoration • National Wildlife Federation – Climate Smart Guidance Project • Delaware Impoundment Management and SDM Team