Understanding the Mechanisms Controlling Storm Event Nitrogen Fluxes from the Lamprey River Watershed Using Continuous in situ Sensors
|Jody Potter||UNH - Department of Natural Resources & the Environment||Technician|
|Chris Cook||UNH - Department of Natural Resources & the Environment||Technician|
|Thor Smith||U.S. Geological Survey||Technician|
|Ania Kobylinski||UNH - Department of Natural Resources & the Environment||Technician|
|Adam Baumann||UNH - Department of Natural Resources & the Environment||Technician|
|Gopal Mulukutla||UNH - Institute for the Study of Earth, Oceans and Space||Technician|
|Wilfred Wollheim||UNH - Department of Natural Resources & the Environment||Principal Investigator|
|William McDowell||UNH - Department of Natural Resources & the Environment||Co-Principal Investigator|
|Kenneth Toppin||U.S. Geological Survey||Associate Investigator|
|Brian Pellerin||U.S. Geological Survey||Associate Investigator|
|James Shanley||U.S. Geological Survey||Associate Investigator|
|Michelle Daley||UNH - Department of Natural Resources & the Environment||Associate Investigator|
|Julia Peterson||N.H. Sea Grant||Associate Investigator|
|Richard Carey||UNH - Water Systems Analysis Group||Technician|
|Lisle Snyder||UNH - Department of Natural Resources & the Environment||Technician|
NHSG research demonstrates impact of land use on nitrogen inputs to Lamprey River
N.H. Sea Grant-funded researchers collected on site data from the Lamprey River to determine nitrogen fluxes in the surrounding watershed. The watershed is composed of various land uses, ranging from agriculture, suburban development and forested lands. Data results compiled in 2014 indicated that agricultural land has as high or higher dissolve inorganic nitrogen exports than suburban land during storms and baseflow. Forested land exported very little nitrate and had very low storm responses. These data results demonstrate the impact of land use on nitrogen inputs to the Lamprey River, thus providing information for resource managers and others making land use decisions in the Seacoast region.
NHSG research indicates presence of nitrate hot spot in the Lamprey River watershed
The Lamprey River watershed encompasses various land uses that contribute differing amounts of nitrogen to the river. N.H. Sea Grant-funded researchers used on site data recorders to learn more about nitrogen fluxes within the watershed. Data results compiled in 2014 indicated that nitrate concentrations tend to increase during certain sections of the hydrograph, leading scientists to believe there is a consistent, concentrated nitrate source at a specific location — often called a source hot spot — in the Lamprey River watershed. These results provide scientists and resource managers with a more detailed understanding of nutrient inputs into the river, thus potentially leading to improved management of nitrogen levels for a healthier ecosystem.
NHSG research sheds light on nitrate fluxes and dilution during storm events on Lamprey River
Storm events enhance the mobilization and transport of non-point nitrogen in a river system. Researchers funded by N.H. Sea Grant used on site sensors to record continuous nutrient flux data from the Lamprey River watershed. Data results compiled in 2014 indicated that nitrate in headwater watersheds tends to dilute during storms. However, this still results in elevated fluxes at all locations because flows increase more than concentrations decline. These results provide scientists and resource managers with more information about nitrogen levels in the watershed, thus providing a basis for land use and resource management decisions.
NHSG research indicates that non-point nitrogen fluxes are impacted by additional processes besides storm events
The Lamprey River watershed is a major source of non-point nitrogen for the Great Bay Estuary. Storm events enhance the mobilization and transport of non-point nitrogen within the Lamprey River, but it is unknown if storm events from this watershed are indicative of all the nitrogen that enters the bay from all sources. N.H. Sea Grant-funded researchers used on site data recorders in the Lamprey River watershed to record continuous data about nitrate levels during storm events. Data results compiled in 2014 indicated that the linkage between watershed and estuarine nitrate levels was much weaker with freshwater flows from storm events despite the watershed being a major source of non-point nitrogen fluxes to the estuary. This suggests that additional inputs from other watersheds or wastewater treatment plants control the nitrate levels in the estuary, leading to levels that change depending on location, season or other factors. These data results provide scientists and resource managers with a more accurate view of nutrient fluxes between the river and estuary for improved resource and nutrient management.
N.H. Sea Grant research indicates conductivity and nitrate are positively correlated in nutrient-impacted watersheds
Very little information regarding riverine storm event nutrient dynamics exists due to the logistical difficulties of collecting sufficient samples throughout an entire storm event across seasons. Previous NHSG-funded research indicates that in situ sensors placed in a river system record more accurate nutrient flux data during storm events than samples obtained by grab samples. Data results compiled in 2014 indicated that conductivity and nitrate concentrations are positively correlated in nutrient-impacted watersheds. This finding will help scientists and resource managers to estimate nitrate fluxes in watersheds where it is not possible to install nitrate sensors.
NHSG research indicates nitrate concentrations are higher in early part of storm events
N.H. Sea Grant-funded researchers conducted studies on the Lamprey River watershed to determine nutrient dynamics during storm events. Data results compiled in 2014 indicated that storm event nitrate concentrations exported from the Lamprey River to Great Bay tend to be higher in the early part of a storm event, possibly due to contributions from source hot spots hear the basin mouth. Because nitrate from these hot spots is rapidly transported out of the system during a storm, there is less opportunity for them to be removed than those sources further up in the watershed. This information will help scientists and resource managers to improve their understanding of the Lamprey River watershed nutrient dynamics and to identify areas of particular concern regarding high nitrate levels.
NH research determines Lamprey River is good indicator of dissolved organic carbon inputs from all Great Bay watersheds
New on site optical sensor technology allows researchers to collect water quality data in a river during storm events for a more accurate picture of nutrient fluxes over time. Data results compiled in 2014 indicated that chromophoric dissolved organic matter (CDOM) — a surrogate for dissolved organic carbon and dissolved organic nitrogen — shows a consistent pattern of increasing concentrations, or "flushing," with storm events. This flushing strongly influences the dissolved organic carbon (DOC) concentrations in the Great Bay Estuary. This suggests that the Lamprey River is a good indicator of DOC inputs from all Great Bay watersheds, and that the watersheds drive estuarine CDOM. These results provide scientists and resource managers with a broader view of nutrient fluxes for improved decision-making regarding land use and nutrient management.
NHSG research indicates high nitrate concentrations coincide with low flows on Lamprey River
Researchers funded by N.H. Sea Grant collected on site data from the Lamprey River to determine nutrient fluxes during storm events and under normal seasonal, low-flow conditions within the watershed. Data results compiled in 2014 indicated that higher nitrate concentrations coincide with low flows in the Lamprey River, with the exception of extremely low flows during the summer. These results provide scientists and resource managers with a better insight into nitrate fluxes in the watershed for improved management of the system and its nutrient inputs.
Nitrogen flux research leads to similar studies in adjacent N.H. watershed with policy implications
N.H. Sea Grant-funded studies in one river to more accurately estimate nitrogen fluxes during storm events led to a similar project in a nearby river.
RELEVANCE: N.H. Sea Grant-funded researchers deployed in situ sensors in the Lamprey River watershed to measure nitrogen fluxes during storm events — measurements not previously recorded due to the level of difficulty involved in sampling during those weather events.
RESPONSE: Using this research as a basis, researchers began a dialogue with the town of Durham, N.H., UNH Facilities, the consulting firm VHB and the Oyster River Watershed Association regarding the monitoring needs in that region to manage elevated nitrogen loads.
RESULTS: This dialogue led to funding for an additional research project in the Oyster River that was modeled after the NHSG-funded project in the Lamprey River. Researchers were closely involved in the Oyster River research — they served on the advisory board, met with the watershed association regularly, and began an intensive monitoring campaign, including a sampling collaboration with the project volunteers. The NHSG-funded research on the Lamprey River watershed clearly serves as a model for other communities interested in improving their estimates of storm event nitrogen concentrations and fluxes.
Water quality research in N.H.’s Lamprey River serves as basis for graduate class
Researchers taught a graduate student seminar based on their N.H. Sea Grant-funded research on Lamprey River nutrient dynamics, providing seminar participants with information they can use in their careers or research.
RELEVANCE: N.H. Sea Grant-funded researchers used in situ sensors to measure nutrient fluxes during storm events and in baseflow conditions in the Lamprey River watershed.
RESPONSE: Using this research as a basis for discussion, researchers taught a graduate student seminar class in 2013 titled “An Aquatic Symphony: Exploring New Insights from Continuous In Situ Measurements in Aquatic Ecosystems.” This two-credit course focused on reading literature and exploring theories of watershed and aquatic ecosystem ecology that can now be tested using the types of sensors deployed as part of the NHSG research project.
RESULTS: Seven students, post-doctoral students and research scientists participated in the seminar, thus helping to inform individuals who are likely to use this information in their own careers or who will teach other students about the diverse applications of water quality research.
Video featuring N.H. nutrient flux research garners hundreds of views, improves understanding of water quality dynamics
Research funded by N.H. Sea Grant focused on nutrient dynamics during storm events and baseflow conditions in the Lamprey River. N.H. EPSCoR produced a video featuring these NHSG-funded researchers deploying sensors in this watershed and explaining why this type of monitoring is important. In 2013, the video garnered 379 views, indicating an interest in this topic by a segment of the public and/or community leaders. Increasing viewership of this video will continue to help provide these audiences with better access to and interpretation of local, real-time research on nutrient dynamics within the Great Bay tributaries.
Field demonstration informs legislators, farmers and companies about impacts of agriculture on N.H. water quality
N.H. Sea Grant-funded researchers deployed in situ sensors in the Lamprey River watershed to measure nitrogen fluxes during storm events — measurements not previously recorded due to the level of difficulty involved in sampling during those weather events. In 2013, researchers participated in the UNH Organic Research Dairy Field Day, where they highlighted their water quality sensor research and explained how it improves the understanding of agricultural impacts on water quality in N.H. As part of this event, researchers led field trips to the monitoring site and explained the experimental design and preliminary results. Participants in these field trips included state legislators, USDA staff, staff from U.S. Senator Jeanne Shaheen’s office, company representatives and regional farmers. This outreach provided an opportunity to engage with individuals and organizations capable of making positive changes to improve water quality in the Granite State.
Interactive demonstration teaches thousands of students and adults about water quality in N.H.’s Lamprey River
With funding provided by N.H. Sea Grant, researchers used in situ sensors to conduct water quality monitoring in the Lamprey River watershed, measuring nutrient fluxes during storm events and in baseline conditions. As part of the outreach efforts associated with this project, researchers and graduate students organized an interactive sensor demonstration exhibit for K-12 students and the general public at the 2013 Ocean Discovery Day program. This two-day event attracted close to 2,000 attendees, many of whom spent time at this exhibit learning about the impacts of stormwater runoff on the water quality of streams. This well-received outreach activity helped to increase the marine and environmental literacy among local youth and adults.
Research-based class at UNH provides hands-on water quality experience to train future workforce
With funding provided by N.H. Sea Grant, researchers conducted water quality studies to determine nutrient fluxes in the Lamprey River during storm events. This research serves as the basis for the UNH Aquatic Ecosystem class (NR 751/851) taught annually by the NHSG-funded researchers. In 2013, researchers led the class on two field trips that complemented project efforts: the first field trip involved a survey of water quality in streams draining different land uses, while the second involved the installation of a permanent sensor array near Wiswall Dam on the Lamprey River. This research-based class helps to train individuals entering the natural resources career fields, providing hands-on, real-world experience to augment their classroom experience.
Year-long water quality monitoring provides continuous data on nitrogen fluxes in N.H.’s Lamprey River watershed
With funding provided by N.H. Sea Grant, researchers conducted studies to evaluate nutrient fluxes during storm events in the Lamprey River watershed. In situ water quality sensors were deployed at strategic locations throughout the watershed to gain a better understanding of biogeochemical fluxes in headwater catchments and the mainstem of the Lamprey and Oyster River watersheds. The year 2013 marked the first year of continuous data over an entire annual period for several monitoring stations in the Lamprey River. This monitoring has allowed for better comparisons of in situ and laboratory measurements. Results from this research will help inform resource managers about patterns of nitrate flushing with storm events throughout the different seasons for improved decision-making about factors that may impact water quality and nitrogen levels.
In situ sensor technology provides more accurate nitrogen flux data in N.H. rivers than grab samples during storm events
N.H. storm events flush a large proportion of non-point source nitrogen into nearby waterways, but the logistical difficulties of collecting sufficient grab samples during storm events to estimate nutrient load has posed a challenge. New in situ optical sensor technology is available that allows continuous nutrient monitoring in streams and rivers for a long-term dataset that includes nutrient concentrations from storm events. In 2013, N.H. Sea Grant-funded researchers compared the results of grab samples to in situ sensor data in the Oyster and Lamprey Rivers. The results indicate that grab samples are inadequate at capturing short-term responses during storm events when most flows occur, especially in watersheds dominated by impervious surfaces. This research will help resource managers utilize the most accurate sampling technology to better understand the sources and fate of non-point nutrient pollution. Some of this research is currently in review at the peer-review journal Environmental Science and Technology.
Research on Nutrient Dynamics Directly Supports Graduate-level Class, Helps Train Future Workforce
NHSG-funded research on Lamprey River nutrient dynamics has directly supported a graduate-level class at UNH and provided hands-on experience in sensor installation and operation for students interested in entering the natural resources career fields.
RELEVANCE: NHSG-funded researchers conducted water quality studies in the Lamprey River using new sensors that allow for continuous monitoring during storm events and baseflow conditions.
RESPONSE: Researchers utilized these studies and technological efforts as a core part of the UNH graduate class Aquatic Ecosystems (NR 751/851).
RESULTS: Students in the class attended field trips to the site in 2012 where they learned how to install and operate the in situ water quality sensor and surveyed the water quality in streams from agricultural, forested and suburban areas. These experiences were highly valuable in training the future workforce to more effectively monitor and manage water resources and nutrients within a watershed.
Storms Cause Varying Degrees of Nitrate Flushes in Lamprey River
The Great Bay Estuary is classified as nitrogen-impaired due to elevated nutrient loads from its surrounding watershed, but very little information is available about the nutrient dynamics during storm events. In 2012, NHSG-funded researchers collected continuous data in the mainstem of the Lamprey River to better understand these nutrient fluxes that likely end up in the estuary. The in situ water quality data showed that there were two major flushes of nitrate during the fall of 2012 with more minor flushes after that, indicating that storms cause varying degrees of nitrate concentrations. These data are helping scientists and resource managers by improving quantification of non-point nutrient inputs to Great Bay and providing greater sensitivity to monitoring changes in nutrient inputs over time.
Video and Article Provide Better Access to Interpretation of Nutrient Dynamics in Tributaries to Great Bay Estuary
NHSG-funded researchers deployed in situ sensors in the Lamprey River to gain a better understanding of nutrient dynamics during storm events and baseflow conditions. A variety of outreach materials were produced in 2012 as a result of this research, including a video and news article that detail the deployment of these new sensors and explain the importance of water quality monitoring for better understanding watershed and aquatic processes. These outreach materials help increase the knowledge and confidence levels of the public and community leaders by providing them with better access to and interpretation of local, real-time research on nutrient dynamics within the Great Bay Estuary tributaries.
Hands-on Exhibit Increases Local Youth Awareness of Water Quality in Lamprey River
NHSG-funded researchers conducted continuous water quality monitoring in the Lamprey River to learn more about nutrient dynamics within the Great Bay Estuary. As part of the outreach efforts associated with this project, researchers and graduate students organized a sensor demonstration exhibit for elementary and middle school students for the 2012 UNH Know The Coast Day program. The hands-on exhibit demonstrated water quality monitoring in a manner that they could understand, such as salt washing off roads into streams and measured by conductivity, and rivers “breathing” through photosynthesis and decomposition as measured by dissolved oxygen. This interactive educational exhibit increased marine and environmental literacy among local youth.
Research Indicates Nutrient Flux Differs among Land-use Sites in Lamprey River Headwaters
Using new in situ optical sensor technology in 2012, NHSG-funded researchers collected continuous data in Lamprey River headwaters to better understand the dynamics and the fate of non-point nutrient pollution in the watershed. They compared three sites: forested, suburban with septic waste and organic dairy. The forested site showed no nitrate concentration response during storms. The overall nitrate fluxes in the suburban and agricultural sites increased during storms and showed diurnal patterns during baseflow conditions. These data are helping scientists and resource managers by improving knowledge of watershed processes and informing nutrient flux models.
New Method Determines Relationship between Nutrient Concentration and Stream Discharge
Researchers have developed a new method of determining the relationship between nutrient concentration and stream discharge. Their new method of processing the data allows the clear visualization of the concentration-discharge relationship, providing valuable information about the source and behavior of nutrients and whether they vary over seasons.
Online Database Stores Water Quality Data
A new Internet-accessible database was developed to store Lamprey River water quality data collected by NHSG-funded researchers, the U.S. Geological Survey and UNH. This database allows resource managers, researchers, watershed associations and other interested parties to have access to important historical and current data to help address management issues in the Lamprey River watershed.
Available from the National Sea Grant Library (use NHU number to search) or NH Sea Grant
- Kaushal, S., W. McDowell, W. Wollheim, T. Johnson, P. Mayer, K. Belt and M. Pennino (2015). Urban evolution: the role of water. Water 7(8):4063-4087, 2015.
- Rosenberg, A., W. Bolster, K. Alexander, W. Leavenworth, A. Cooper and M. McKenzie (2005). The history of ocean resources: modeling cod biomass using historical records. Frontiers in Ecology and the Environment 3(2):84-90.
- Deegan, L., D. Johnson, R. Warren, B. Peterson, J. Fleeger, S. Fagherazzi and W. Wollheim (2012). Coastal eutrophication as a driver of salt marsh loss. Nature 490(7420):388-394, 18 October 2012.
- Carey, R., W. Wollheim, G. Mulukutla and M. Mineau (2014). Characterizing storm-event nitrate fluxes in a fifth order suburbanizing watershed using in situ sensors. Environmental Science and Technology 48(14):7756-7765, 2014.
- Wollheim, W., T. Harms, B. Peterson, K. Morkeski, C. Hopkinson, R. Stewart, M. Gooseff and M. Briggs (2014). Nitrate uptake dynamics of surface transient storage in stream channels and fluvial wetlands. Biogeochemistry 120:239-257, August 2014.
- Kaushal, S., W. McDowell and W. Wollheim (2014). Tracking evolution of urban biogeochemical cycles: past, present and future. Biogeochemistry 121(1):1-21, October 2014.
- Mineau, M.M., W.M. Wollheim and R.J. Stewart. An index to characterize the spatial distribution of land use within watersheds and implications for river network nutrient removal and export. Geophysical Research Letters 42(16):6688-6695, August 2015.
- McDowell, W.H. NEON and STREON: opportunities and challenges for the aquatic sciences. Freshwater Science 34(1):386-391, March 2015.
- Shonka, N. (2014). Water quality sensors provide insight into the suspended solids dynamics of high flow storm events in the Lamprey River. Master's thesis, University of New Hampshire.
- Price, A. (2014). Nitrate dynamics across temporal scales and land use types in three headwater catchments observed using high-frequency measurements. Master's thesis, University of New Hampshire.
- EPSCor Lamprey River water study (2013) (video).