The CRT monitors the the number, cover and species of plants in eighty 3x3 meter permanent quadrats spread through the new Lower, Middle and Reservoir wetlands. We classify plants as native and non-native, and wetland or non wetland-dependent. Because we quantified plants in the retired bog before restoration (the "before"), we can now track plants over time in the restored wetlands (the "after"). Post-restoration monitoring so far has shown a large jump in both number and diversity of species, with many more native plant species than before the restoration. More than one hundred native plant species germinated from seeds that had been buried in the soil of Lower Wetland for over 300 years, first under mill ponds and then cranberry bogs.
In March 2018, with funding from the Town of Falmouth Water Quality Monitoring Committee, the Woods Hole Research Center began measuring the concentrations of the different forms of nitrogen in the water of the Coonamessett River approximately every two weeks. WHRC measures ammonium, nitrate, dissolved organic nitrogen and particulate organic nitrogen at eleven stations from the outlet of Coonamessett Pond to the head of tide at Route 28. The WHRC's Cape Cod Rivers Observatory also measures the same forms of nitrogen every two weeks at the former Middle Bog dike and just upstream of Sandwich Road. We are interested in determining what role a restored wetland plays in removing harmful nitrogen from groundwater before it reaches the estuary and causes algal blooms.
The CRT measured cross sections and habitat types in the Coonamessett River reach through the former Lower Bog soon after farming ceased. Measurements showed a broad, sandy, shallow channel in most places. This was a problem for the fish because it left them exposed to osprey, herring and other predators. It also meant the water warmed up quickly, which is not good for these migratory fish. The first post-restoration profiles that we measured in late summer 2019 documented a narrower, deeper channel with more gravel and aquatic vegetation habitat. This new habitat provides places for fish to hide from predators, and good habitat for insects, which are eaten by the fish. We plan periodic new measurements after restoration.
Since 2017, volunteers have been collecting and identifying benthic (on the streambed) macroinvertebrates before and after restoration. Areas of lower bog which were sandy from cranberry production were dominated by leeches, amphipods and snails. Following restoration, the more coarse substrate is supporting, in addition to the prior species, greater diversity of insect larvae such as caddis, chironomids and mayflies .
Photos: Alison Leschen