National Estuarine Research Reserve System
background background
search icon
Home Site Map Contact Us
space backgroud
  Home > Research > Science Collaborative
 NERRS Science Collaborative
sky background
Managing Nonpoint Nitrogen Pollution in New Hampshire's Great Bay
Managing Nonpoint Nitrogen Pollution
The Great Bay National Estuarine Research Reserve is working with the University of New Hampshire and other partners to better understand how nitrogen pollution flows into New Hampshire's Great Bay.

They are locating nonpoint nitrogen hot spots within its watershed, identifying the sources of that nitrogen, and characterizing how streams, rivers, and riparian buffers can mitigate the impact of this nitrogen on the Bay.

Ultimately, they aim to provide local managers with a clear understanding of which sources of nitrogen, under which land use conditions, pose the greatest threat to Great Bay’s water quality.

Why this project?

Nitrogen levels in Great Bay have increased significantly in recent years. Local managers need better information about where the nitrogen pollution is coming from so that they can implement cost effective strategies to reduce nitrogen pollution’s impact on important coastal resources.

Local Context

In 2009, a report noted that the total nitrogen load to Great Bay had jumped 42 percent in only five years. Water clarity was declining and nitrogen-fed algae populations were on the rise. Eelgrass meadows were shrinking, taking with them their capacity to stabilize sediment and support marine life ranging from oysters and lobsters to flounder and cod. Oxygen levels were dipping, and dead zones were likely in the cards.

Seventy percent of this nitrogen comes from nonpoint sources like septic systems and lawn fertilizer. Historically, tributary rivers and streams have been able to treat much of the nitrogen they receive before it reaches the Bay. Yet as the amount of nitrogen flowing into these tributaries increases, their ability to cope with this pollution diminishes.

How much of what kind of nitrogen would cause this sensitive dynamic to fail completely is not well understood. Until it is, local communities face a ticking time bomb that they lack the science to defuse.

Maintaining local water quality has long been a priority of the Great Bay Reserve. This project is building on the Reserve's System-Wide Monitoring Program (SWMP) data, habitat maps used to benchmark the impacts of land use change, and partnerships with local decision makers focused on managing and improving water quality.

Project FAQs

What’s the goal?
Address a critical gap in the scientific understanding of how nitrogen flows into Great Bay.

Download a project overview (PDF)

What’s new?
Read the latest progress report

Visit project web page

Where is it happening?
Coastal New Hampshire

Which Reserve is involved?
Great Bay NERR

What’s new?
Read the fall 2011 progress report

Who needs the science?
Great Bay NERR
New Hampshire Department of Environmental Services
Piscataqua Regional Estuaries Partnership
Local municipalities & watershed associations

Who’s on the project team?
Great Bay NERR
University of New Hampshire
Piscataqua Regional Estuaries Partnership    
UNH Cooperative Extension

What’s the time frame?
10/2010 to 10/2013

Where can I learn more?
William H. McDowell
Principal Investigator, Professor,
& Director
NH Water Resources Research Center at the University of New Hampshire
(603) 778-0015

Steve Miller
Stakeholder Integration Assistance & Coastal Training Program Coordinator at the Great Bay NERR
(603) 778-0015

     Last Updated on: Thursday, December 13, 2012
Science Collaborative
    For more information contact
National Oceanic and Atmospheric Administration | National Ocean Service | Web Site Owner: Ocean and Coastal Resource Management | Site Map | Disclaimer | Privacy Policy | NERRS Webmaster | NERRS Staff Only | ERD Staff Only

Home Side Map Contact Us