Making Meaning at Tidmarsh

Seven years post restoration, 51 people from 21 organizations assembled at Mass Audubon's Tidmarsh Wildlife Sanctuary to walk, explore, and learn how this wetland restoration has responded to the restoration intervention. The goal of the day was to learn together about the process of recovery at Tidmarsh, and collect insights that can be applied to other wetland restorations of cranberry farmland.

Stop 4: Before/After

Restoration Actions

• Remove earthen berm
• Fill existing ditches
• Construct a new tributary channel to Fresh Pond
• Dig deeper pond (up to 10 feet deep)
• Create small open water areas by removing sand
• Roughen bog surface; note that eastern areas do not have apparent peat subsurface.

Design

Expectations

This will remain a drier area of the site.
Some of the site will become a marsh migration area; there are no dams downstream.
This is a higher area of site; will not be as quickly affected by sea level rise (Nick)
Shallow excavations where sand was removed ot peat would stay wet.
Pond will support a variety of reptiles and amphibians.

Concerns

Pond was only 8' deep when berm around it began to cave in. Sumco stopped pumping water away.
Should have disturbed less peat.
Heavy pit and mound makes it difficult to mow in the future; might have been better for bird habitat.

Observations collected from all participants

• Very dry.
• Walk in was dry.
• Lots of poison ivy.
• Stream slow moving, bottom is solid.
• Pond creation provides unique habitat features.
• Pond is good for N attenuation.
• Distinctly wetter than rest of area.
• Depressions are largely vegetated; no standing water at this time of year.
• Spongy, sedgy, peat meadow - unlike other stops.
• Feels different from pit and mound areas - no sapplings.
• Wetland dominant species.
• Area has a "mystery area" feel to it.
• Lovely microhabitat surprises.
• Heavy pit and mound expensive.
• Spike rush dominent, Sagitariat sagitifolia, Button bush (likely planted).
• Painted turtle, musk turtle, snapping turtle; pickerel, green bullfrogs, many fish (catfish, sunfish, small mouth bass); watersnake, swan nest. (Monitoring)
• Crayfish, larvae of amphibians near drier area of large pond.
• Butterflies, a lot of dragon flies, tree swallows.
• Ospery (particularly in spring).
• Would love to see long term data.
• Large sections of deep sphagnum to the North.

Recommendations

Don't excavate into peat ball. Doing so you give off a lot of GH gas.
Transition edges in drier areas; don't pit and mound
Maybe not blanket sand removal or microtopography but grade slope all the way from stream to edges.
More experiments using bio-char or bark chips to fill ditches. (We dont yet know benefits of this technique).

Photo credits L to R: Beattie, Hackman, Watts, Hatch

Photo credits L to R: Beattie, LO.

On to Stop 5, Ballantine Square.