Monitor the hydrodynamics and sediment supply to a newly engineered system. Buzzards Bay Coalition and their partners have just completed Phase I of this project to create an engineered salt marsh on a former fill area. Sediment supply is a key factor in salt marsh sustainability with rising sea-level, this site provides a unique opportunity to study the establishment of the engineered system under the natural forcing of the tides and water flow.
Location
Marsh Island site New Bedford Harbor, Acushnet River, Fairhaven, MA..
Summary
We have deployed three instruments, on two fence-post mounted platforms and one bed-mounted platform, under the footbridge in the center of the channel on the seabed. The first fence-mounted platform contains a Sontek IQ+, which measures water velocity and flow every 15 minutes. This yields a volumetric water flux over each tide, and any net flux in/out during storms and rainfall events. Adjacent to this, connected with a power cable, is a submersible battery on a bed mounted fiberglass grate, weighted down with ~ 60 lbs.
On the second platform, we have a YSI EXO2, which measures water depth, turbidity, salinity, pH, oxygen, fluorescent dissolved organic material, and chlorophyll every 15 minutes. Along with water samples, we can convert the turbidity signal to suspended sediment, and with the flow data, compute sediment fluxes in/out of the system. This platform also has an RBR Dwave, which measures wave height and period.
These instruments will remain on-site for the duration of the experiment, which ideally will last until the system is completely vegetated and in a quasi-equilibrium. We will conduct site visits every 1-2 months to collect water samples, check the instruments, download data, and add battery power. Disturbance at the site will be minimal as the platforms will stay in place and the instruments will be temporarily removed. Water sampling will be conducted from the footbridge with a handheld sampler.
We installed 2 wells at the site (Site A: 41.652024, -70.915786, depth below surface 72.5 cm; Site B: 41.651435, -70.914968, depth below surface 37 cm) to determine water levels in the subsurface. Installation was done with a sediment auger. During install we noted that sediments at Site A were sandy with phrag root chunks, underlain by a clay layer and Site B had heaving (liquified) sand at depth. Each well has a CTD (In-Situ AquaTroll 200) measuring conductivity, temperature and depth. A barometer was installed on the observation platform. All instruments are recording at 15 minute intervals.
Aerial surveys using sUAS (small Uncrewed Aircraft Systems) will provide a bare earth elevation model using structure from motion photogrammetry and lidar technology to map the surface of Marsh Island. Vegetation models will be constructed from information collected from a micaSense Altum multispectral camera also flown over the newly constructed marsh. Ground control targets were placed to georeference the imagery. Surveys will be conducted at a minimum of twice per year to capture changes in topography and vegetation seasonally and on an annual time scale.
Info derived
Time-series data of water level, currents, flow/discharge, waves, turbidity, and other water-quality parameters (temperature, salinity, chlorophyll, dissolved oxygen, pH, fDOM, blue-green algae). Supplemental water samples will be collected and analyzed for total suspended-sediment concentration and loss-on-ignition. Grain-size distribution will be determined from sediment samples collected the marsh creek bed. Aerial mapping will provide full elevation coverage and multispectral orthoimage data. Biochem time-series sensor data are groundwater well CTD measurements.
Comments
This will be an ongoing study and would like it to be an event type field activity.
Multiple Information specialists due to group overlap.
Entries for this field activity are based on entries from Field Activity 2023-025-FA.
Bo and Olivia turned around the Dwave, Exo, and IQ
2024-04-09
2024-04-09
S. Brosnahan and S. Ackerman visited site with UAS equipment and flew the M600 YellowScan Mapper+ (lidar and RGB camera) attached. Mavic and Anafi might be flown too. AeroPoints were deployed as ground control.
2024-04-22
2024-04-22
Jen O'Keefe-Suttles, Emily Tacke, Jin-Si Over, and Robert Bales visited the site. Wells were sampled and checked, the Exo and IQ under the bridge were serviced and replaced. Base station occupied the new PK nail on the bridge and the RTK equipment was used to take a transect across the channel and on the equipment.
2024-05-21
2024-05-21
Bo and Olivia connected IQ to new battery, downloaded data, changed "Record Multicell Data" setting to 1, and restarted data collection.
2024-05-22
2024-05-22
Swap well loggers, download barometer, surface water collection. Emily Tacke and Dakota Sievers
2024-06-20
2024-06-20
Tidal creek tidal sampling. Meagan Eagle Amari Johnson
2024-06-24
2024-06-24
Bo and Olivia turned around the Dwave, Exo, and IQ.
2024-06-25
2024-06-25
Tidal creek tidal sampling. Emily Tacke, Amari Johnson
2024-07-02
2024-07-02
Bo, Jen C, Seth, Amari (student), and Ezra (volunteer) did two sUAS flights with the Skydio X10 for a MIR aerial imagery data collect for photogrammetry. A GPS ground survey with the SP80 was also done.
2024-07-12
2024-07-12
Water sampling from bridge over the timeseries instruments on same interval as Exo. Water samples will be filtered for SSC and used to convert Exo turbidity (NTU) to SSC (mg/l). Personnel: Bo and Olivia
2024-07-19
2024-07-19
Tidal creek tidal sampling for geochemical constituents. Meagan Eagle Amari Johnson
2024-08-21
2024-08-21
S. Ackerman, J. Cramer, J. Over, M. Bartlett visited site with UAS equipment and flew the M600 with YellowScan Mapper+ (lidar and RGB camera) and the Altum (multispectral camera) attached. Also flew the new Skydio x10 (RGB and thermal camera). Mavic and Anafi might be flown too. AeroPoints were deployed as ground control. This fieldwork day was coordinated with researchers from the Buzzards Bay Coalition who are in the field this week doing vegetation and elevation surveys.
2024-09-17
2024-09-17
Bales and De Meo working at site under pedestrian bridge. Switching out dWave and Exo, downloading data from IQ and re-deploying. Collecting RTK data on new instruments and across the channel for IQ flow calculations.
2024-09-30
2024-09-30
Tidal creek tidal sampling. RTK wells. Retrieved well CTDs and barometer. Emily Tacke, Rachel Einecker
2024-10-15
2024-10-15
Change batteries and power setting on deployed IQplus. This should allow for longer deployments (up to 6mos). Steve Suttles and Bo Bales.
2024-12-17
2024-12-17
Switching out Exo and Dwave under bridge at MI site. Download IQ data and redploy with same batteries currently installed. RTK creek and collect water samples.
Bales and De Meo
Lidar data collected with YellowScan Mapper+ and provided as a point cloud and gridded terrain and surface model. Images from the YellowScan Mapper+ were used to create an orthomosaic.
Multispectral aerial imagery collected from UAS (DJI Matrice 600) equipped with the Altum-PT. Image locations are provided in a CSV. Bands include (RGB, NIR, Red-Edge, Thermal).
