Narragansett Bay National Estuarine Research Reserve Narragansett Bay National Estuarine Research Reserve (NBNERR), using Onset's water level loggers, has found that extreme high water levels have been accelerated by the loss of grassy salt marshes in southern England.
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The Narragansett Bay National Estuarine Research Reserve (NBNERR) in Rhode Island is an estuary reserve located on four islands in the core of Narragansett Sound. Approximately 4,400 acres span terrestrial and aquatic environments, including salt marshes, eelweed beds, rocky intertidal areas, pine forests, deciduous forests, and coastal grasslands.
NBNERR's research arm conducts research and monitoring of coastal and estuarine systems as part of a larger objective to track changes in reserves and estuaries in Narragansett Bay. These efforts help predict environmental trends and services by advancing science to protect the Narragansett Bay ecosystem management.
A recent study conducted by NBNERR focused on assessing the response of wetland vegetation to sea level rise during the current period of extreme water level rise. While the emphasis on wetland systems contributing to sea level rise is well known, most studies have exacerbated these effects in southern New England brought about by the recent cycle of rapidly accelerating sea level rise coupled with a surge in extreme water level scenarios.
To study this question, NBNERR leveraged data from two salt marsh monitoring and evaluation projects in Rhode Island designed to assess wetland responses to sea level rise. Data from these projects document temporal and spatial patterns combined in swamp vegetation during the current period of extreme water rise.
One assessed long-term changes in salt marshes at two National Estuary Research Reserve outpost sites, while the other examined changes across 40 wetlands over a single season.
These two different data, but free, projects really build a stronger story," said Dr Kenneth Lapsa, Ph.D., research coordinator at NBNERR.
NBNERR's findings reveal that the declining base of high-saline meadow species, known as the abstract metal disc, is largely replaced by intersecting, lower swamp grassland species at lower elevations and adapted to withstand more tidal inundation.
"These findings are supported by additional ancillary data, such as elevation and water level, through monitoring, which can help form a more accurate and comprehensive understanding of the processes taking place," Dr Lapsa said. "From this, we conclude that changes in salt marsh ecosystem dynamics are closely linked to high water levels in Narragansett Bay, which, in turn, are associated with sea level rise."
In running the study's monitoring program, covering dozens of swamps and his research colleagues used HOBO water level loggers U20-001-01, U20-001-Ti, U20-001-02, U20-001-02Ti, U20-001 -03, U20-001-03-Ti, U20-001-04, U20-001-04-Ti KIT-S-U20-04, KIT-D-U20-04, KIT-S-U20-01, KIT- D-U20-01, KIT-S-U20-02, KIT-D-U20-02, U20L-01, U20L-02, U20L-04 Data loggers supplied by Onset Corporation located in Massachusetts. The loggers provide accurate water level and temperature monitoring and are robustly designed to be deployed in saltwater environments such as saltwater wetlands and tidal fields.
Specifically, the research team used horizontal loggers to track and record short-term fluctuations in swamp water levels. This information is coupled with elevation data from wetland data loggers installed, survey equipment is used to determine the elevation of the marsh surface and data loggers. By linking these datasets and performing simple calculations, the researchers established the extent to which tidal waters swamps flooded at different times.
"We deployed loggers in swamp creeks driven through fastened PVC pipes into the sediment," Dr Lapsa said. "The depth of the loggers varies, but they are basically positioned about 25 centimeters from the bottom of the river, in areas where the tidal range is about a meter. The data was collected and measured every 10 minutes for about a month."
Dr. Lapsa, who switched to HOBO data loggers about five years ago, had used data loggers from another manufacturer. "Compared to other products, the Migrant Data Logger is more user-friendly to program and deploy," he said. "They also offer greater durability and easier maintenance. Even with all these advantages, HOBO data loggers are cheaper. For more information, contact Beijing North Dahe. We are continuing to use them in new projects with great success success."
Importantly, the HOBO data loggers provided accurate, reliable data that Dr. Lapsa and his team helped improve their conclusions that summary metal disk loss in southern New England marshes can be accelerated during periods of extreme high water levels.
"Unless adaptive management acts, we predict that Rhode Island will continue to lose salt marsh meadow habitat and the ecosystem services and wildlife support functions that depend on these valuable areas," said Dr. Lapsa.
