Mount Hope Bay Marine Buoy Continuous Probe Data

Data from water quality monitoring buoys in Mount Hope Bay.

Seasonal monitoring in Mount Hope Bay is part of the Narragansett Bay Fixed-Site Monitoring Network (NBFSMN) and provides water quality information for a sub-embayment of upper Narragansett Bay.

Table of Contents

About the project

In partnership with the Rhode Island Department of Environmental Management (RIDEM), the University of Rhode Island Graduate School of Oceanography (URI-GSO), and EPA’s Southeast New England Program (SNEP) for Coastal Watershed Restoration, MassDEP operates two fixed-location marine water quality monitoring buoys in Mount Hope Bay. The seasonal (May-November) monitoring is part of the Narragansett Bay Fixed-Site Monitoring Network (NBFSMN) and provides data in the Massachusetts portion of Mount Hope Bay, a sub-embayment of upper Narragansett Bay. These data not only help address data gaps in MA estuarine monitoring, but also facilitate a more comprehensive assessment of water quality in the Massachusetts portion of Mount Hope Bay. Additional MassDEP water quality management objectives served by these data include the evaluation of potential revisions to marine surface water quality standards, and calculation of effluent discharge limits that could cause or contribute to impairments in the bay.

Ortho photo of Mount Hope Bay

Since 2016 (pilot year), the buoys have been deployed in the same approximate locations. The “Cole” buoy is located near the mouth of Cole River within Assessment Unit MA61-07 (Class SA). The “Taunton” buoy is located near the mouth of Taunton River within Assessment Unit MA61-06 (Class SB). Each monitoring buoy is outfitted with multiprobe sondes at the surface (approx. depth of 1.0 meter) and in the bottom waters (approx. 0.5 meters above the sea floor), as well as a nitrate probe at the surface. The sondes measure data every 15 minutes (depth, temperature, dissolved oxygen, specific conductance, salinity, chlorophyll, and blue-green algae). The nitrate probes measure nitrate-nitrogen hourly. Data are stored in the buoy instrumentation and telemetered via cellular communications. URI-GSO staff deploy, maintain, and retrieve the buoys in accordance with MassDEP’s direction and per the EPA-approved NBFSMN Quality Assurance Project Plan. Data are quality-reviewed, validated, and finalized by MassDEP.

A summary report of the 2017/2018 monitoring results can be found here:

There are two water quality assessment units (AUs) in Mount Hope Bay: MA61-07 and MA61-06. For the latest assessment and listing decisions for these two AUs, go to the Integrated List of Waters Report (IR) here:

Measured water quality parameters on each buoy deployed in Mount Hope Bay.
(15-minute measurements, surface & bottom)
Sea-Bird SUNA V2
(hourly measurements @ surface)
Depth (meters) Nitrate-Nitrogen (NO3-N) (mg N/L)
Temperature (°C)  
Dissolved Oxygen (mg/L)  
Dissolved Oxygen Saturation (%)  
Specific Conductance (µS/cm)  
Salinity (Practical Salinity Units)  
pH (Standard Units)  
Chlorophyll (Relative Fluorescence Units)  
Phycoerythrin (Blue-Green Algae [Marine]; Relative Fluorescence Units)  


Design of buoys in Mount Hope Bay


Data Files for Mount Hope Bay Marine Buoys

Data Disclaimer - These data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and metadata have been reviewed for accuracy and completeness and approved for release by MassDEP, no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

Help Us Improve  with your feedback

Please do not include personal or contact information.