Mission: Phragmites in Brunswick's Thomas Cove salt marsh
Are phragmites and other invasive plants increasing in a recently restored marsh in Brunswick Maine?
In August 2011, a small culvert under Adams Road in Brunswick was replaced with a larger structure that lets more water flow with the tide in and out of Thomas Cove salt marsh. This change makes the marsh more salty and wetter during the highest high tides. Curtis Bohlen and The Casco Bay Estuary Partnership (CBEP) want your help with their monitoring project to see if invasive plants start showing up in the marsh as a result of the changed conditions. Go check out the marsh! Do you see phragmites, or other species of concern? Let CBEP know!
1. Print the species cards for Phragmites australis and other species of concern:
2. Print a Upland Species Survey datasheet
3. Go to the Thomas Cove salt marsh to look for the species of concern
4. Go to your My Vital Signs page to add your "found" or "phragmites not found" observation
Why this Mission matters
Since August 2011, the new larger culvert under Adams Road has increased the amount of water on the Thomas Cove salt marsh during high tides, and has increased the amount of salt in the surface and ground water. These changes are expected to change which species are found in the salt marsh, and where they are found. Areas upstream of the culvert are likely to experience the most change.
Scientists with the Casco Bay Estuary Partnership are managing a 5-year monitoring program to see how the marsh plants change over time. They will study plants throughout the wetland and collect data on changes to the species that live there. The plan does not include a formal effort to search for plants of concern - that's where YOU can make a huge contribution to this effort!
Here's what the scientists think might happen. What do you think?
- Saltier water upstream of the road may lead to less freshwater wetland plants and more salt tolerant plants
- More water circulating on the marsh may make the marsh more resistant to invasive species
- If invasive species do turn up, phragmites is most likely due to its salinity tolerance. There is a known patch of phragmites a few hundred yards downstream of Adams Road.
- Other freshwater species of concern may show up or become troublesome like invasive purple loosestrife (Lythrum salicaria), native narrow leaved cattail (Typha angustifolia), native broad-leaved cattail (Typha latifolia), and their hybrid, white cattail (Typha x glauca).
The only way to make sure that invasive plants are not increasing in the marsh is to go out and look!
Curtis Bohlen, Casco Bay Estuary Partnership
Your observations of these species (or of any other invasive wetland plants on the site!) will be of great help in tracking the effects of the salt marsh restoration project. Vital Signs observations will be especially valuable to CBEP scientists since they include photographs and GPS coordinates.
Want to know and do more?
Do repeated surveys!
Repeated surveys over the next few years would help track changes in prevalence of invasive plants.
Map and measure!
More ambitious members of the Vital Signs community could map or measure the size of existing stands of phragmites and cattail to determine whether they grow or shrink over the next few years.