Effects of Local Shoreline and Subestuary Watershed Condition on Waterbird Community Integrity in the Chesapeake Bay Impacts of shoreline hardening and watershed land use on nearshore habitats aka “NOAA Shorelines Project” NOAA-CSCOR Funded Research (2009-2014) 17 Principal Investigators from 8 Institutions Goals • Improve scientific knowledge about effects of stressors in near-shore environments (<2m deep) • Transition new knowledge to improve management of near-shore environments Compare shoreline types Natural Marsh Phragmites Rip-Rap Bulkhead Beach Marsh Forested Residential Development Agricultural …in bays and sub-estuaries with watersheds that have differing land use Objectives – Waterbird Component • Improve our understanding of the effects of shoreline hardening and land use on waterbird communities using the Chesapeake and Coastal Bays • Work in conjunction with the other macro-fauna groups Credit: Johann Schumacher (fish and invertebrates), How to Assess Waterbird Community Usage? Community Metrics: Species Richness, Diversity Species level abundance/density; Guilds 1. Index of Waterbird Community Integrity (developed by DeLuca et al. 2008) 2. Subestuary Scale (plus 2 others) Index of Waterbird Community Integrity (IWCI) (After DeLuca et al. 2008. Biol. Conserv.) IWCI = (∑ S IWCI / S N) + (2) A I ALSO: Species Richness Where: S IWCI = Individual Species Index Species Density SN = Total no. of species Guild Analysis AI = Abundance score for each species (i) Weighted for sensitive versus tolerant species Indices Foraging Breadth Nesting Sensitivity Migratory Status Breeding Range State Listing Native Status Index of Waterbird Community Integrity SIWCI (range 21 to 5) Disturbance Sensitive Species Disturbance Tolerant Species Royal Tern Ring-billed Gull (Thalasseus maximus) (Larus delawarensis) Siwci = 21 Siwci = 9.5 Hooded Merganser Double-crested Cormorant (Lophodytes cucullatus) (Phalacrocorax auritus) Siwci = 20 Siwci = 9.5 Semipalmated Sandpiper Canada Goose (resident) (Calidrus pusilla) (Branta canadensis) Siwci = 18.5 Siwci = 8.5 Laughing Gull Mallard (Leucophaeus atricilla) (Anas platyrhynchos) Siwci = 17.5 Siwci = 7 Bald Eagle Domestic duck (Haliaeetus leucocephalus) Siwci = 5 Siwci = 16.5 Resident versus Migratory Canada Geese MIGO = Siwci 12 (disturbance sensitive) CAGO = Siwci 8.5 (disturbance tolerant) • September 15 – MD DNR threshold for migrant CAGO • Compare summer surveys (should be resident) to Fall • Confirm using survey notes (on lawns) Adaptations to Deluca et al 2008 1. Updated IWCI species database a) Standardize IWCI index scores definitions Foraging Niche Nesting Site Selectivity Migratory Distance Breeding Range Conservation Status b) Score all species for Chesapeake Bay (n=120 spp) 2. Deluca used 100m transects; we used area counts and densities because it was hard to find contiguous shoreline types at that scale Prosser et al. 2017 In Press . Waterbirds Methods Area Counts– survey shoreline and open water from boat Each site visited 2 seasons per year (2010-2014) Late Summer (Aug-Sept) and late Fall (Oct –Dec) Each site visited 3 times per season Calculated Index of Waterbird Community Integrity, species richness, and density by subestuary and season Shoreline Delineations (GIS and Groundtruth) Shoreline Type Beach Bulkhead Developed Forest Natural Marsh Open Water Phragmites Rip Rap Curtis Old Road Bay Study Sites (n=21) Langford Stony 2014 Corsica 2014 Curtis Creek (Dev) Magothy 2013 Old Road Bay (Dev) Rhode Onancock River (Mix Ag) 2012 Occohannock River (Mix Ag) Miles 2013 Harris 2011 Corrotoman River (For) 2010 Harris Creek (Agr, MixDev) Mill Creek (MixDev) St. Leonard Honga Mill Creek Mill 2012 Magothy River (MixDev, Dev) St. Mary’s Miles River (Agr, MixDev) Stony Creek (Dev) 2011 Back River (Dev) Onancock East River (For) Corrotoman Poquoson River (Mix Dev) – Poq East and West Ware River (For) Occohannock 2010 East Corsica River (Agr) Ware Honga River (Oth Mix) Langford Creek (Agr) Poquoson Rhode River (For) St. Mary River (Oth Mix,For) St. Leonard Cr. (For) Back A total of 64 species were observed American Black Duck Forster's tern Red-breasted Merganser American Coot Gadwall Redknot American Great black-backed Ring-necked Duck Oystercatcher gull Red-necked Grebe Bald eagle Great blue heron Royal tern Black-crowned Night Great egret Ruddy Duck Heron Green heron Sanderling Belted kingfisher Greater Yellowlegs Sandwich Tern Bonaparte's Gull Herring gull Short-billed Dowitcher Brown Pelican Horned Grebe Semipalmated Plover Bufflehead Hooded Merganser Canada goose Killdeer Semipalmated Sandpiper Canvasback Laughing gull Snowy egret Caspian Tern Little Blue Heron Spotted sandpiper Common Goldeneye Lesser Scaup Surf Scoter Common Loon Least tern Tri-colored Heron Common Merganser Long-tailed Duck Tundra swan Common tern Mallard Western Sandpiper Double-crested Mute swan Wood duck Cormorant Osprey Yellow-crowned Night Domestic duck/goose Pied-billed grebe Heron Fish crow Ring-billed gull 2014 Summer Surveys (Aug-Sept) IWCI Mean No. Mean Shoreline Density by Sub-estuary Birds Species Length Shoreline Observed Richness (km) Length Curtis Creek 54.39 21 17.09 3.48 16.93 Old RoadBay 26.13 17 16.66 1.45 14.26 OccohannockRiver 22.07 17 37.517 0.58 16.53 Onancock River 15.69 19 50.147 0.29 17.78 Top three species (abundance): Laughing Gull Double-crested Cormorant Canada Goose 2014 Fall Surveys (October-December) Mean No. Mean Shoreline Density by IWCI Sub-estuary Birds Species Length Shoreline Observed Richness (km) Length Curtis Creek 35.69 17 17.09 2.09 16.86 Old RoadBay 17.79 15 16.66 1.07 15.63 OccohannockRiver 46.05 17 37.517 1.23 17.27 Onancock River 44.04 15 50.147 0.88 17.22 Top three species (abundance): Bufflehead Canada Goose (Resident) Herring Gull IWCI Scores by Season Paired t-test Summer 14.13 to 19.62 Summer x=16.94 Fall 15.63 to 19.73 Fall x=17.36 p=0.057 19 18 17 IWCI Summer 16 Fall 15 14 Three Scales of Shoreline/Landcover Categorization: 1. Shoreline (Bird Survey Area) 2. Landscape 500m around bird survey boundary 3. Landscape Watershed Shoreline Delineation – Shoreline Scale Corsica Honga Langford Rhode St. Leonard Beach St. Mary Back Bulkhead East Poq. East Developed Poq. West Ware Forest Magothy Stony Natural Miles Marsh Corrotoman Phrag Harris Marsh Mill Creek Riprap Curtis Creek Old Road Bay Occohannock Onancock 0% 25% 50% 75% 100% Landscape Analysis – 500m from shoreline Corsica Honga Langford St. Leonard St. Mary's Rhode Back East DEV Poquoson CROP Ware GRAS Magothy FOR Miles WETL Stony Corrotomon Harris Mill Old Road Bay Curtis Occohannock Onancock 0% 25% 50% 75% 100% Landscape Analysis – Watershed Corsica Honga Langford St Leonards St Marys Rhode Back East Poquoson DEV Ware CROP Magothy GRAS Miles FOR Stony WETL Corrotoman Harris Mill Old Road Bay Curtis Occohannock Onancock 0% 25% 50% 75% 100% IWCI by Dominant Landscape (Summer) IWCI Forest Agriculture Developed p=0.23, ANOVA Univariate regression (α ≤ 0.20) to determine variables for Model Selection (Full Model) Summer Fall Shoreline (7): Shoreline (7): Bulkhead Bulkhead Rip Rap Rip Rap Developed (lawns) Developed (lawns) Phragmites Phragmites Natural Marsh Natural Marsh Forest Forest Beach Beach 500m (5) Watershed (5): 500m (5) Watershed (5): DEV500m DEV DEV500m DEV CROP500m CROP CROP500m CROP GRASS500m GRASS GRASS500m GRASS FOR500m FOR FOR500m FOR WETL500m WETL WETL500m WETL Backwards Model Selection Regression: IWCI and shoreline/land use AIC ∆ AIC R2 Season Model Score c Late Summer Null 72.10 -- -- Full Model: Bulkhead + Phragmites Marsh + 69.95 2.15 0.62 Natural Marsh + WETL500m + (WETL500m) 2 Step 2: Bulkhead + Phragmites Marsh + 66.70 3.25 0.50 Natural Marsh Step 3: Bulkhead + Phragmites Marsh 63.94 2.76 0.49 Late Fall Null 60.97 -- -- Full Model: Bulkhead + Riprap + Natural 3.14 0.38 Marsh + DEV500m 64.11 Step 2: Bulkhead + Riprap + DEV500m 60.36 3.75 0.38 Step 3: Bulkhead + DEV500m 57.94 2.42 0.34 Step 4: Bulkhead 56.90 1.04 0.28 Birds are responding to effects at the shoreline scale! p=0.002 IWCI Score Percent Bulkhead p=0.04 IWCI Score Percent Phragmites Hardened vs. Non-hardened Shoreline (hardened= bulkhead and rip-rap) Hardened Non-hardened p=0.020 p=0.024 Threshold Limit of Bulkhead Development on IWCI Threshold? Cumulative Cumulative Probability of Threshold a Looking Beyond the IWCI Shorebirds Shorebirds x Wetland Positive relationship at Subestuary and Watershed Scales Shorebirds x Natural Marsh Shorebirds x Wetland (NLCD06) shoreb = - 0.3570 + 0.04752 GS_NM shoreb = - 0.3879 + 0.2957 WETLAND06 6 6 5 5 4 4 3 3 shoreb shoreb 2 2 1 1 p=0.002 0 0 p=0.003 0 2 4 6 8 10 12 0 10 20 30 40 50 60 70 80 WETLAND06 GS_NM Mallards Mallards x Development Positive relationship at Subestuary and Watershed Scales Mallards x Bulkhead Mallards x DEV (NLCD06) MALL = - 2.618 + 1.309 GS_BH 60 MALL = - 0.081 + 0.3833 DEV06 60 p=0.06 50 50 40 40 30 MALL 30 20 MALL 20 10 p<0.001 10 0 0 10 20 30 40 0 GS_BH 0 10 20 30 40 50 60 70 DEV06 Canada Goose density driven by Landscape level Cropland Corsica Honga Langford St Leonard St Marys Rhode Back East Poquoson East Poquoson West DEV Poquoson CROP Ware Magothy GRAS Miles FOR Stony Corrotoman WETL Harris Mill East Mill West Mill Curtis Creek Old Road Bay Geese x Landscape CROP Onancock Occohannock 6000 S 741.273 0% 25% 50% 75% 100% R-Sq 86.8% R-Sq(adj) 85.9% 5000 Geese x Local Natural Marsh 4000 6000 S 1942.76 R-Sq 15.5% R-Sq(adj) 3.5% 5000 3000 4000 p=0.31 2000 3000 Number of Geese Number MaxGoose 2000 1000 1000 0 0 p<0.001 0 10 20 30 40 50 60 70 80 GS_NM 0 10 20 30 40 50 60 70 CROP06 Looking across macro-fauna groups Perry et al.