monitoring bird, fish, and vegetation communities at prime ...vegetation community response methods...
TRANSCRIPT
Susan GuiterasSupervisory Wildlife Biologist
USFWS – Coastal Delaware National Wildlife Refuge Complex
USFWS (Refuges): Nathan Bush, Annabella Larsen, Jennifer McAndrews
USFWS (Fisheries): Steve Minkkinen, John Gill
University of Delaware: Elizabeth Tymkiw, Greg Shriver, Tim Freiday, Mac McGraw
DNREC: Lyndie Hice-Dunton, Bob Scarborough, Andrew Howard, Alison Rogerson, Drexel Siok, Kenneth Smith
Monitoring Bird, Fish, and Vegetation Communities
at Prime Hook NWR Before, During, and After Tidal Marsh Restoration
10,000 acres, mostly wetlands
Two central units – Unit II and Unit III – managed as freshwater impoundments for waterfowl habitat through installation of water control structures in 1980’s
Impoundment management successful until series of storms created breaches in Unit II shoreline
Hurricane Sandy brought largest final blow to the system
Rapid peat collapse and extensive conversion to open water in Unit II and Unit III
Tidal Marsh Restoration
Prime Hook NWR
Largest tidal marsh restoration project in the east at ~4000 acres
Based on extensive hydrodynamic modeling with local data
SHORELINE RECOVERY
Closure of large breaches
Restoration of 8900 ft of shoreline, dune, and back barrier platform
MARSH RESILIENCY
Dredged ~25 miles of interior tidal channels in Unit II and Unit III
Remove WCS, DelDOT bridge
Thin layer deposition on site
Tidal Marsh Restoration
Comprehensive Biotic & Abiotic Monitoring Program Cooperative Agreement with DNREC
Coastal Programs / DNERR Wetland Assessment
University of Delaware Chris Sommerfield, Tom McKenna,
Greg Shriver, Chris Williams
USFWS Maryland Fish & Wildlife Conservation Office USFWS Northeast Regional I&M and LMRD staff Refuge staff USGS Rutgers University
Monitoring our Progress
Biological Monitoring Overview
• 15-20 Bird & Vegetation Survey Points in each unit
• Unit I (north) and Unit IV (south) serve as reference areas
• Fish survey locations varied, focused at WCS and in channels
Vegetation Community Response
METHODS
• Salt Marsh Integrity (SMI) and Saltmarsh Habitat and Avian Research Program (SHARP)
• 50-meter radius around bird survey points
• Community cover types and dominant species
• Point-intercept transect (100 meters long)
• Photopoints (North, East, South, West)
• Mid-Atlantic Tidal Rapid Assessment Method (MidTRAM)
• Habitat Attribute: Bearing capacity, horizontal vegetation obstruction; Also - biomass, RTK elevation
• NVDI (Normalized Difference Vegetation Index)
• Open Water : Vegetated Marsh ratio from imagery
Vegetation Community Response
RESULTS / HIGHLIGHTS - SMI / SHARP / MidTRAM
• No in-depth analysis of vegetation community data yet
• Above- and below-ground biomass collected pre-restoration and will be repeated after a few growing seasons
• Changes in bearing capacity and local elevation depend on presence (or not) of dredged material deposition
• Resurgence of marsh vegetation along the periphery of both units, and in areas of deposition following dredging
• Photopoints currently most compelling data
Vegetation Community Response
Vegetation Community Response
Pluchea odorata(Saltmarsh fleabane)
Leptochloa fascicularis(bearded sprangletop)
Spartina alterniflora(Saltmarsh cordgrass)
Eleocharis parvula(dwarf spikerush)
Echinochloa crus-galli(barnyardgrass)
Vegetation Community Response
Dredged channel and thin-layer deposited material
Vegetation Community Response
Planted back-barrier platform
Vegetation Community Response
Many areas still show little change – yet!
Vegetation Community Response
RESULTS / HIGHLIGHTS – NVDI
• “Hot off the Press”
• Preliminary results, not closely examined yet
• Different imagery sources (USDA NAIP vs DigitalGlobe WorldView3)
• Tide timing not controlled
• In restoration units, % open water starting to drop
• Unit I had also been affected by increase in flooding and ponding
Total Unit
Acres
2015 % Open
Water
2016 % Open
Water
2015 2016 2015 2016
Unit I (East) 805 255 178 550 628 32% 22%
Unit I (West) 851 133 78 718 773 15% 9%
Unit II 1438 1249 996 189 442 87% 69%
Unit III 2335 1504 1299 830 1036 64% 56%
Open Water
(acres)
Vegetated Marsh
(acres)
Vegetation Community Response
• Some large areas in Unit III adjacent to dredged channels, where material has been sidecast, filled in substantially
Vegetation Community Response
• Planted vegetation in back barrier area is evident (dune not included in analysis)
Vegetation Community Response
• Creek coves in western Unit II filling back in as water levels drop following breach closure
• Cods Rd example at the end of previous talk (Scarborough)
Bird Community Response
METHODS
• Salt Marsh Integrity (SMI) and Saltmarsh Habitat and Avian Research Program (SHARP)
• 15-20 bird survey points per unit (including adjacent salt marsh units as reference)
• 5-minute passive point count followed by secretive marshbirdcallback sequence
• 3 visits per year (usually)
• Ultimately… Tidal Marsh Obligate (TMO) analysis
• Beach nesting birds
• Routine surveys in partnership with refuge volunteers and state DNREC staff
• Nest monitoring and protection
• Integrated Waterbird Management & Monitoring (IWMM)
• Year-round routine roadside surveys by refuge staff
Bird Community Response
RESULTS / HIGHLIGHTS – Saltmarsh Birds (SMI/SHARP)
Unit II Shoreline Recovery
(Not surveyed)
(Not surveyed)
(Not surveyed)
Bird Community Response
Shorebird increase on newly created mudflats in both units
Bird Community Response
RESULTS / HIGHLIGHTS – Beach-nesting Birds
First ever documented Piping Plover nest on the refuge.
Unfortunately, not successful, but a great start
Can you spot the eggs?
Bird Community Response
RESULTS / HIGHLIGHTS – Beach-nesting Birds
Most “robust” least tern(LETE) colony in the state for years• Peak numbers over
100 birds• Close to 20 nests• Successfully fledged
at least 3 young
American oystercatchers (AMOY) nested but were not successful
All together now… “Awwwww!”
Horseshoe Crab Response
RESULTS / HIGHLIGHTS – Horseshoe Crab Spawning
More horseshoe crabs than expected in first year!
Pre-restoration surveys were not quite in the same area (further north on existing un-restored beach), but will be a useful reference for comparison
Fish Community Response
METHODS
• Seasonal fish community surveys
• 2014 (Summer, Fall); 2015 (Spring, Summer, Fall); 2016 (Spring, Summer)
• Fyke nets, Seine nets, Clover traps (varied as restoration progressed)
• Acoustic tags deployed to see how diadromous fish are using the system prior to, during, and after restoration
• 8 receiver sites (11 in 2015)
• Tag data downloaded seasonally (more often at first), data comes from other researchers in the network as well
Fish Community Response
RESULTS / HIGHLIGHTS – Fish Community Surveys
• Results thus far still being summarized
• Species that increased:
• White perch
• Sheepshead minnow
• Black drum
• Species caught 2016 not detected previously:
• Atlantic croaker
• Diamondback terrapin
• Species that decreased:
• Common carp
• Killifish spp
• Silverside spp
• Mummichog
PRE-RESTORATION• Many fish not detected after <2 months – mortality, moved out of range, missed detection?• Only one fish documented moving through breach (2014-2015, before closure)• Evidence of fish emigrating out of refuge through both north and south routes• Limited documentation of fish moving through freshwater creeks• Several fish detected outside of refuge (one alewife turned up in NJ!)
Several different tagging efforts between Sept 2014 – Nov 2016
139 acoustic tags out
Species Acoustic Tags
Floy/ PIT tags
Total
American eel
49 56 105
White perch
83 514 597
Alewife 7 0 7
Striped bass
0 1 1
Ongoing Monitoring
• Post-restoration monitoring will continue
• Partnerships funded at least in part until 2019
• Applied for Hurricane Sandy funding for longer term monitoring
• Some monitoring will be the “new order of business” for refuge biology program
Thank You! Any Questions?
Behind the Scenes
• Laura Mitchell
• Curtis George
• Mike Mensinger
• Zac Duval
• John Biddle
• Drexel Siok
• Christina Whiteman
• Kenny Smith
• Andrew Howard
• Alison Rogerson
• Katie Bell
• Chris Townsend
• Collin Thomas
• Rodrick Murray
• Melissa Vorn