Integrated Nutrient Observatory

Overview: Over the past several years, NERACOOS and its partners have tested and deployed a prototype automated nutrient monitoring observatory in the coastal and estuarine waters of the Northeast. The goal of this effort was to demonstrate the delivery of high frequency nutrient data to scientists, managers, and policy makers.

An award from the Integrated Ocean Observing System (IOOS) Ocean Techology Transition (OTT) program has funded this project. The nutrient observatory is currently transitioning into an operational service and is being supported but IOOS and the Environmental Protection Agency (EPA).

News and Events

March 2019: NERACOOS has concluded the Integrated Nutrient Observatory webinar series. Recordings of each webinar, with details and abstracts can be found under the Resources tab of this page.

February 2019: NERACOOS has rescheduled the Integrated Nutrient Observatory Webinar Series. Please see the Resources tab for more information.

We apologize for any inconvenice caused by the postponement due to the partial government shutdown. Below Please find the new schedule for the webinars which will highlight the outcomes of this project.

Winter 2019: NERACOOS will be hosting a series of webinars to highlight the outcomes of the Nutrient Observatory project. Throughout this webinar series you will learn about the nutrient data collected, the sensors deployed, and the challenges and lessons learned from operating automated nutrient sensors in various marine systems in the Northeast.

This webinar series will be on hold until the partial government shutdown is resolved. Once the shutdown has ended, we will send out the webinar schedule and registration information. We appreciate your patience and look forward to sharing the results of this project with you

Spring 2016: Deployement and redeployement in Great Bay, Gulf of Maine and Long Island Sound. 

December 2015: Sensor training at the University of Connecticut 

June 6, 2015: NERACOOS Buoys E and I were re-deployed with nitrate sensors at a depth of 50m and the data from these sensors will be available through our data buoy map after the sensors have been calibrated.

May 26, 2015: Great Bay Sensor Workshop

April 22, 2015: The great Bay buoy was deployed on April 22nd with two new automated nutrient sensors. These sensors will measure nitrate and phosphate concentrations in Great Bay several times a day. 


Project Partners:


Funded by:


Project Schedule:

Below are the tentative deployement dates of nutrient sensors throughout the NERACOOS Region. 

Spring 2017:

  • Narragansett Bay Deployment, Narragansett Bay Commission 

Spring 2016:

  • Long Island Sound Deployment, University of Connecticut 
  • Great Bay Re-Deployment, University of New Hampshire
  • Gulf of Maine Buoy E, I, M & N, University of Maine

April 2015:

  • Great Bay Deployment, University of New Hampshire

May 2015:

  • Great Bay Estuary Stakeholder workshop

June 2015:

  • Buoy E and I Deployment, University of Maine

​July 2015:

  • Long Island Sound Deployment, University of Connecticut

September 2015:

  • Buoy M and N Deployement, University of Maine


Nutrient Sensor Information:

NERACOOS will deploy several automated nutrient sensors that will be integrated into our buoy systems and will deliver nutrient readings several times a day.

Ammonium (NH4) – WET Labs CYCLE-NH4 Ammonium Sensor

  • Designed for unattended long-term moored operations, the Cycle NH4 is one  of WET Labs' line of single analyte chemical sensors.

Nitrate (NO3) – Satlantic SUNA V2

  • This nitrate sensor is a chemical-free solution for autonomous monitoring of nitrogen-based nutrient concentrations in ocean, estuarine and high turbidity freshwater environments.

Phosphate (PO4) – WET Labs Cycle Phosphate Sensor

  • Designed for unattended long-term moored operations, the Cycle PO4 is the first of WET Labs' line of single analyte chemical sensors.

Integrated Nutrient Observatory Webinar Series - 2019

Data, Successes, and Challenges

March 15, 2019

"Transitioning State-of-the-Art Nutrient Sensing Technology to Develop an Operational Nutrient Observatory for NERACOOS"
Presented by Andrew Barnard and Adam Dutton, Sea-Bird Scientific

Sea-Bird Scientific is the world's largest developer and manufacturer of products for the measurement of parameters for oceanographic research and environmental water quality monitoring in natural waters. Since 2010, Sea-Bird Scientific has worked with scientists to further the understanding of biogeochemistry with nutrient sensors to measure otho-reactive phosphate with the Cycle-PO4 and the Submersible Ultra-violet Nitrate Analyzer (SUNA). In 2016, Sea-Bird Scientific made efforts to re-engineer improvements into the SUNAv2 and update the design of the phosphate auto-analyzer releasing the HydroCycle-PO4. Together with NERACOOS, lessons learned were applied to improve deployment longevity and service regimens through introducing an onboard QA/QC flagging system in HydroCycle to help operational monitors react to the possible problems with the data quality that occur in remote sensing. 

"Lessons Learned from Operating and Maintaining Automated Nutrient Sensors on Operational Buoy Systems in the Northeast"
Presented by Nutrient Sensor Operators: Tom Gregory, University of New HampshireKay Howard-Strobel, University of Connecticut; Dave Townsend, University of Maine;  and Heather Stoffel, University of Rhode Island

Integrated Nutrient Observatory sensor operators will discuss some of the challenges, successes, and lessons learned from the project including integrating sensors into operational moorings, operating and maintaining sensors in estuarine and coastal environments, and conducting QA/QC on the data. 

"NERACOOS Integrated Nutrient Observatory Data Access"
Presented by Riley Young-Morse, Gulf of Maine Research Institute

This presentation demonstrates how to access, plot, and download data from the Integrated Nutrient Observatory project using the NERACOOS ERDDAP system.

Great Bay and Narragansett Bay

March 7, 2019

"Nutrient Variability in Great Bay, NH"
Presented by Tom Gregory and Joe Salisbury, University of New Hampshire

In this presentation, Tom and Joe will focus on data and results from the NERACOOS Integrated Nutrient Observatory project. Sea-Bird Scientific nitrate and phosphate sensors were deployed on the Great Bay buoy during ice-free months over the past several years. These data show a local annual cycle and springtime nutrient draw-down and regeneration as winter approaches. Variability imposed by episodic events such as high discharge and edpisodic mixing during storm periods was also observed. Further, data from these sensors can be used with ancillary temperature, salinity, and oxygen data to diagnose phytoplankton behavior. Future work includes attribution of high nutrient events to processes including those influences by human activity.

"Nutrient Monitoring in Narragansett Bay"
Presented by Heather Stoffel, University of Rhode Island

Rhode Island had been working on Nitrogen reductions over the past 10+ years. With reductions reaching the 50% reduction goals, monitoring nutrients and changes in environmental conditions is an integral part of the assessment process. The Narragansett Bay Fixed-Site Monitoring Network (NBFSMN) is a key program in providing water quality data and analyses to coastal managers as part of this process. This talk focuses on how continuous monitoring of nitrate, using SUNA, can help to improve scientists understanding of water quality within Upper Narragansett Bay. 

Gulf of Maine and Long Island Sound

February 28, 2018

"Nutrient Dynamics in the Gulf of Maine: New Insights Gained via Moored SUNA Nitrate Sensors"
Presented by: Dave Townsend, University of Maine

In this presentation Dave reviewed the current understanding of the basic workings of water mass and nutrient fluxes to the Gulf of Maine, highlighting recent observations of fluctuating pulses of difference water masses from outside the Gulf of Maine and their accompanying nutrient loads, as revealed by moored SUNA nitrate sensors together with other data sources.

"Initial Observations of Nitrate and Phosphate from Western Long Island Sound"
Presented by: Kay Howard-Strobel, University of Connecticut

High frequency time series of nitrate and phosphate concentration data collected during the summers of 2017 and 2018 at the Western Long Island Sound buoy station are presented along with other water quality characteristics. Kay will discuss methodology, implications for process interactions, and petential use in water management decisions.


Great Bay Stakeholder Workshop - 2015

On May 26, 2015 NERACOOS hosted a workshop in Greenland, New Hampshire for local stakeholders. The goal of the workshop was to inform stakeholders about the NERACOOS Integrated Nutrient Observatory project and specifically the deployment of nutrient sensors in Great Bay, as well as to discuss their potential use of the data.

Workshop Final Report

Joe Salisbury, University of New Hampshire
     "Great Bay Oceanography and Nutrient Dynamics"
Ru Morrison and Cassie Stymiest, NERACOOS
     "NERACOOS and Integrated Nutrient Observatory Overview"
Ted Diers and Steve Couture, NH Department of Environmental Services
     "Great Bay Water Quality Management"
Corey Koch, Sea-Bird Scientific
     "Overview of Automated Nutrient Sensors"