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Jan 11, 2024 380 likes •544 views

Marsh response to shallow runnels at Winnapaug and Ninigret Ponds Wenley Ferguson, Save The Bay Dr. Al Gettman, DEM Region-wide assessment of Narragansett Bay and South Shore salt marshes: 2012-2014 Monitored vegetation every 10 meters and

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Wenley Ferguson, Save The Bay

Dr. Al Gettman, DEM

Marsh response to shallow runnels at Winnapaug and Ninigret Ponds

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 Monitored vegetation every 10 meters and

width of plant communities

 Measured bearing capacity  Additional data: salinity, mosquito

density, fish presence

Region-wide assessment of Narragansett Bay and South Shore salt marshes: 2012-2014

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Defined pool in foreground versus shallow standing water Mosquito breeding habitat Barren peat Shallow impounded water

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Marsh Adaptation Strategies

In Marsh

 Drainage enhancement of expanding

impounded water areas through excavation of shallow creeks or runnels

 Sediment placement

Marsh Migration

 Remove of physical barriers to marsh

migration i.e. walls/dams/roads

 Land conservation

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Runnel projects Proposed runnel projects Marsh migration facilitation projects

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6-8” 12” 10” 12 - 16”

small runnels large runnels

Runnel range of profiles

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Runnels dug through ditch spoils: 2013 2011

Winnapaug Marsh: Westerly

1st runnel project in collaboration with RIDEM

Mosquito Abatement Program in 2013

2013

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Winnapaug Marsh

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0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00%

Open Water Bare Salicornia depressa Spartina alterniflora Spartina patens

% Cover

2011 2013 2014 2015 2017 2019

Runnels installed spring 2013

Winnapaug Marsh Vegetation Percent Cover

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Winnapaug Pond DEM Land

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Winnapaug Pond Audubon Society and Westerly Land Trust

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Ninigret Pond East: DEM Land

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