Targeted Research Results for Communities and Agencies

North Carolina Sea Grant

Responding to concerns by the U.S. Fish & Wildlife Service, NC State University researchers funded by North Carolina Sea Grant developed a mesocosm study to determine impacts of rerouting water into the Alligator River National Wildlife Refuge as part of a proposed wetland restoration project. Study results enabled the project to move forward. Data indicated no negative impacts on the refuge waterways, but rather significant nitrate reduction should occur within the wetlands prior to discharge to Alligator River National Wildlife Refuge.

  • North Carolina Sea Grant
  • 2013
  • Impact
 
Relevance: US Fish & Wildlife Service partners were concerned that rerouted agricultural drainage water through restored and existing wetlands into the northern portion of Pamlico Sound would potentially lead to eutrophication of waters in the Alligator River National Wildlife Refuge (ARNWR). 

Response: NC State University’s Biological & Agricultural Engineering Department, with North Carolina Sea Grant funding, developed a wetland mesocosm study to test nitrogen removal in simulated conditions in the wetland restoration areas. 

Results: Preliminary results indicated that significant nitrate-nitrogen removal will occur in the wetlands if managed properly, and this will prevent the rerouted water from causing a threat to areas outside of the restoration. USFWS partners used this information to make an informed decision to allow the restoration project to move forward as designed. Therefore, once the restoration is complete, agricultural drainage water will be rerouted into the wetlands and reduce the volume of water and nitrogen currently discharged into the Pamlico Sound.
Associated Project(s):

 

Partners: North Carolina Coastal Federation; North Carolina State University (NCSU); US Fish and Wildlife Service (US DOI, FWS); USDA-NRCS;

National Focus Areas: Healthy Coastal Ecosystems; Sustainable Coastal Development

Program Focus Areas: HEALTHY COASTAL ECOSYSTEMS; SUSTAINABLE COASTAL DEVELOPMENT

Recap: Responding to concerns by the US Fish & Wildlife Service, NC State University researchers funded by North Carolina Sea Grant developed a mesocosm study to determine impacts of rerouting water into the Alligator River National Wildlife Refuge as part of a proposed wetland restoration project. Study results enabled the project to move forward. Data indicated no negative impacts on the refuge waterways, but rather significant nitrate reduction should occur within the wetlands prior to discharge to ARNWR.

Relevance: US Fish & Wildlife Service partners were concerned that rerouted agricultural drainage water through restored and existing wetlands into the northern portion of Pamlico Sound would potentially lead to eutrophication of waters in the Alligator River National Wildlife Refuge (ARNWR).

Response: NC State University’s Biological & Agricultural Engineering Department, with North Carolina Sea Grant funding, developed a wetland mesocosm study to test nitrogen removal in simulated conditions in the wetland restoration areas. 

Results: Preliminary results indicated that significant nitrate-nitrogen removal will occur in the wetlands if managed properly, and this will prevent the rerouted water from causing a threat to areas outside of the restoration. USFWS partners used this information to make an informed decision to allow the restoration project to move forward as designed. Therefore, once the restoration is complete, agricultural drainage water will be rerouted into the wetlands and reduce the volume of water and nitrogen currently discharged into the Pamlico Sound.
Response: NC State University’s Biological & Agricultural Engineering Department, with North Carolina Sea Grant funding, developed a wetland mesocosm study to test nitrogen removal in simulated conditions in the wetland restoration areas. 



Results: Preliminary results indicated that significant nitrate-nitrogen removal will occur in the wetlands if managed properly, and this will prevent the rerouted water from causing a threat to areas outside of the restoration. USFWS partners used this information to make an informed decision to allow the restoration project to move forward as designed. Therefore, once the restoration is complete, agricultural drainage water will be rerouted into the wetlands and reduce the volume of water and nitrogen currently discharged into the Pamlico Sound.

Response: NC State University’s Biological & Agricultural Engineering Department, with North Carolina Sea Grant funding, developed a wetland mesocosm study to test nitrogen removal in simulated conditions in the wetland restoration areas. 



Response: NC State University’s Biological & Agricultural Engineering Department, with North Carolina Sea Grant funding, developed a wetland mesocosm study to test nitrogen removal in simulated conditions in the wetland restoration areas. 

Featured Story: Mesocosms, Sensors and Otoliths: Tools to Improve North Carolina Water Quality

North Carolina Sea Grant develops varied techniques and technologies that address water quality issues

 

Monday, September 08, 2014

By Rhett Register, North Carolina Sea Grant

 

With its 17 river basins, nearly 38,000 miles of rivers and streams, and more than 3,000 square miles of estuaries, North Carolina offers challenges for preserving and enhancing water quality.

North Carolina Sea Grant develops varied techniques and technologies that address water quality issues. Research teams study the ability of restored wetlands to control runoff, test new sensor technology to monitor water quality in tidal marshes, and verify that fish ear bones, known as otoliths, can identify early-life habitats of fish. 

Mike Burchell checks the depth of the groundwater near the proposed restoration site. Credit: Rhett Register

 

Mike Burchell has reduced agricultural runoff to Albemarle Sound, part of the second largest estuary system in the lower 48 states and an area vital to N.C. fisheries. An agricultural engineer with NC State University, Burchell’s work with the U.S. Department of Agriculture (USDA), the N.C. Coastal Federation, area farmers and North Carolina Sea Grant has shown how wetlands he helps restore remove fertilizer in stormwater flowing from area farms toward shellfish habitat. 

Stormwater in the project area historically flowed northward into what is now the Alligator River National Wildlife Refuge. Partner farmers opted to participate in a USDA program that funds wetland restoration, a move that would reduce, with Burchell’s help, the amount of runoff to the sound.

But Scott Lanier, deputy manager of the refuge, was concerned that the redirected water could affect the refuge’s river and lakes. “We deal with invasive plant species control. Those lakes can be impacted by alligator weed. We didn’t want to see any other stressors on there that would negatively impact them,” he says. 

François Birgand (foreground) and Randall Etheridge place equipment for monitoring water quality in a restored marsh in Carteret County. Credit: Randall Etheridge.

 

With funding from Sea Grant and the N.C. Water Resources Research Institute, Burchell addressed Lanier’s concerns using a mesocosm study that recreated wetland conditions in the laboratory. Results showed that a band of restored wetlands between the farm and the refuge would remove pollutants including bacteria, turbidity and fertilizer.

Working with Burchell on another wetlands restoration project, also funded by Sea Grant and WRRI, François Birgand, employs next-generation water-quality sensors to study restored tidal marshes. Birgand and his team at NC State use the sensors to sample water at high frequencies.

Scientists have had the capability to measure the physical properties of water — such as temperature, salinity, pH and flow — at 15-minute intervals for decades. Resource managers need the ability to routinely and cheaply measure respective nutrient concentrations. “The novel sensor package developed by François’ team has solved this problem — greatly increasing our ability to understand the nutrient dynamics in these critically important marsh systems,” says John Fear, deputy director for North Carolina Sea Grant and WRRI

Hughes can use the chemical signal from the otoliths of this large adult striped bass collected in the Roanoke River to pinpoint areas of Albemarle Sound that were important habitat. Credit: Coley Hughes.

 

Water quality differs among waterbodies. Scientists use otoliths as a kind of in-flight data recorder to understand where fish have spent their life. By examining chemicals in the rings of the pebble-like bones and comparing them to chemicals in a waterbody, researchers can determine at what stage in its life a fish traveled from one waterbody to another.

The otolith data is important to fisheries managers seeking to protect and restore key larval rearing areas and other fish habitat. Until now, however, scientists did not know how a waterbody’s chemical signature might change over space and time — and thus how accurate otolith information would be.

With North Carolina Sea Grant funding, Coley Hughes at East Carolina Universitydocumented the chemical make-up of eight coastal waterbodies over space and time. After reviewing samples from different depths across long stretches of rivers monthly for three years, Hughes supports the use of otoliths to answer management questions. Her results may even increase the resolution of otolith data.

Christine Jensen, a biologist in the Habitat and Enhancement Section of the N.C. Division of Marine Fisheries, speculates that managers could use the data to identify tributaries — and the parts of these systems, such as upstream or downstream — that are favored as spawning grounds and nursery areas for important fisheries. “That level of information,” Jensen says, “would provide direction on where we should focus restoration efforts.”

These innovative studies have or will be featured in Coastwatch magazinencoastwatch.org. Burchell in Winter 2014, Birgand in Summer 2014 and Hughes in the upcoming Autumn 2014 issue.

 

 

 

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