Living Shorelines for Master Gardeners David O’Brien National Marine Fisheries Service Gloucester Point, VA Frequently Asked Questions MGs hear from the public about shorelines • What to plant on steep slopes? • What resources are available for local educators? • What to do about an undercut bank? • What can be done about boat wake erosion? • What to do with a shady, eroding bank? • ItdittIs anyone studying ways to capture, stabilize and plant river silt. Coir • How do you identify marsh rolls are too expensive and short grasses? lived; sand bags? • What grasses should I plant in the • Isn’t there a law to make pppeople marsh area (perhaps after killing all who live/own businesses on the the phrag)? water protect the shorelines from • Where can I get these plants and pollution and excessive nitrogen? when/how should they be planted? • How can we create and consistently enforce standards that protect fragile shorelines and yet permit reasonable development? • What do you do if you try to protect the shoreline and your neighbor doesn’t? Cumulative Impacts of Shoreli ne H ard eni ng • Forest loss & fragmentation • Wetland loss • Sediment supply & transport altered • Static shoreline, reduced biodiversity • Aquatic habitat loss Non-Structural & Hybrid Alternatives for Erosion Protection “Living Shorelines” • Succession of natural vegetation buffers – Riparian buffers – Tidal marshes – SdbhSand beaches – Shallow water reefs & underwater grasses • GdGradual ll slopes • Ecosystem services are maintained Least MOST Suitable SUITABLE Bayfront & main Upper tributaries reaches of narrow creeks MAYBE Lower reaches, wider creeks Target Area for Vegetative Buffers BkFBank Face Bank Toe High Marsh Low Marsh ItInter tidlAtidal Area Upland Tidal Wetlands Subaqueous Land Fastland Tidal Marshes (vegetated) Subtidal Area Riparian Buffer Tidal Flats (not vegetated) Shallow Water Habitat Beaches (intertidal or supratidal) Planting the Bank Face Natural re-generation + mulch + planting natives use species already growing on the slope Storm • Eastern red damaged area cedar • Wax myrtle • American holly • Mountain laurel • Sumac • Switch grass • Andropogon grass Planting zones for graded banks Riparian buffer Bank face Bank toe & intertidal area Only occasionally flooded Partially flooded during RllfldddiRegularly flooded during during storm tides regular lunar high tides normal high tides; subject to boat wake erosion Occasional storm tides Existing bank Graded bank 3:1 slope or flatter Spring high tides MHW Small trees & Salt bushes and shrubs mixed with other shrubs with MLW perennials and dense cover of ornamental deeply-rooted Dense cover of grasses grasses deeply-rooted grasses Planting Tidal Marshes The most suitable shorelines for planting tidal marshes have: – wide, gradual slopes from the upland bank to MLW – sandy, aerobic substrate – plenty of sunlight How wide should the marsh be? • The answer depends on the energy regime in your area—the bigger the waves, the wider the marsh !! • Typically a minimum of 15 feet • Bank grading or filling out into the water may be needed to widen the intertidal zone Fringe Marsh Low marsh High marsh Salt Bushes StiSpartina StiSpartina Iva frutescens alterniflora patens Baccharis halimifolia Planting zones MHW MLW parallel the tide lines Channelward edge of pltdlanted area at mid-tide level Birdsong Wetland Norfolk, VA Embayed or “Pocket” Marsh Tidal connection More complex MHW Low marsh planting zones High marsh VIMS Teaching Marsh Gloucester Pt, VA Typical Marsh Grass Species Used Low Marsh High Marsh Salt grass Distichlis spicata SltSaltmars h cor d grass SltSaltmea dow hay Spartina alterniflora Spartina patens More species possible for low salinity or fresh water, select those that remain above ground during winter e.g. Spartina cynosuroides, Juncus effusus Switch grass Panicum virgatum Salt Bushes ppglanted at landward side of high marsh Not as flood tolerant, use at upland edge Wax myrtle / Bayberry Groundsel Bush Marsh Elder Morella cerifera Baccharis halimifolia Iva frutescens M. pennsylvanica Planting Sand Beaches • Beach nourishment may be required • Use dune plants • May be combined with structures; sills and breakwaters Yorktown Beach, VA Typical Dune Plants & Recommended Planting Time Foredune Backdune Sea oats Saltmeadow hay Uniola paniculata Spartina patens (Mar 1 – Apr 15) (May 1 – Jun 15) American beach grass Bitter panicum Ammophila breviligulata Panicum amarum (Nov 1 – Apr 1) (Apr 1 – May 1) “Hybrid” Methods where vege ttildttation alone does not provid e enough stabilization Low-profile structures + sand fill + v egetation bu ffers Coir fiber logs Stone marsh sills Fiber log before sand fill & plants to repair To be filled with clean sand then planted storm erosion of natural marsh Stakes should be cinched together where wave action might lift logs out of place Marsh Sill with Planted Marsh at VIMS since 1983 WtWater front Demonstration Gardens Yorktown Beach Holly Point Nature Park Deltaville, VA Yorktown Beach Plants tolerate salt, wind, occasional tidal flooding Yorktown Beach Salt bushes & wax myrtle Switch grass – 3 cultivars Coneflower & other blooming perennials Yorktown Beach Small trees – American sycamore, hackberry Low shrubs – VA sweet spire, Indian hawthorn, wax myrtle, salt bushes Ornamental grasses – switch grass, river oats Blooming perennials – New England aster, rugosa rose SithSwitch grass ( PiPanicum v irgat um ) River oats ( Chasmanthium latifolium ) Holly Point Nature Park Failing timber bulkhead High tides at bulkhead at extreme low tide = too deep for planting atdt grade Existing fringe marsh in background Shading from overhanging, desirable trees Holly Point Nature Park Fiber logs + sand fill + tree pruning May 2007 Holly Point Nature Park Planted tidal marsh after settling period June 2007 *Note alignment with natural marsh edge Holly Point Nature Park Planted tidal marsh after 1st growing season August 200 7 Also enhancing the understory of forest slope Contact Info: David O’Brien NOAA Fisheries Service Virg ini a I nstit ut e of M ari ne S ci ence 804-684-7828 David.L.O’[email protected].