Progress 06/21/00 to 09/30/05

Outputs
The project objectives were to improve estimates for nutrient (nitrogen, phosphorus) loadings to the Neuse Estuary, including characterization of mass water transport; determine impacts of major storms on water quality and aquatic communities; examine localized impacts of anthropogenic pollutants; and enhance understanding of factors leading to fish kills. This project contributed to the most detailed long-term database in existence on the Neuse, from eight stations in the upper-mid estuary. We also designed and installed a series of automated platform stations that have provided near-real-time data (hourly, 24/7) on the Neuse, the first of its kind in a North Carolina estuary. It has yielded accurate, publicly accessible data (www.waterquality.ncsu.edu) on physical, chemical, and biological conditions in the Neuse throughout the project, including detailed characterization of water quality impacts from storm events. We coupled this system with boat-mounted acoustic Dopplar current profiling to obtain more accurate estimates of volume of flow to/from the estuary. The detailed dataset on nutrient concentrations and volume of flow were used to calculate nutrient loading. Time series evaluations of the data (trend analysis statistical models, both parametric and nonparametric) indicated that an apparent 30% reduction in total nitrogen loading to the Neuse Estuary from 1998-2003 occurred because a severe drought (2000-2002) temporarily reduced nonpoint source inputs. More recent trend analyses, considering data from 1993-2005 (i.e. an additional 2 years of data), now show that there has been no change in total nitrogen loading to the estuary over the past 12 years (i.e. no 30% reduction). Thus, nutrient reductions from improved management practices in the Neuse watershed have been offset by increases in human and swine populations and related factors. This component of the project points to the need for targeting reductions in additional nonpoint (major urban and agricultural) sources in order to reduce nutrient pollution, algal blooms, and fish kills in the Neuse Estuary. In other findings, storm events increased pollutant loadings to the estuary, and in particular, high precipitation events in winter-early spring added inorganic nitrogen spikes that stimulated large phytoplankton blooms, including the toxigenic dinoflagellate, Prorocentrum minimum. Localized impacts of anthropogenic nutrient inputs were evident in both depressed bottom-water dissolved oxygen levels and elevated chlorophyll a concentrations (indicative of increased phytoplankton biomass), both in violation of State water quality standards, at certain stations. Regarding fish kill assessment, the cause of a small proportion of major fish kills could not be identified, but most fish kills were related to low dissolved oxygen problems, another symptom of nutrient over-enrichment. The automated platform stations, which were sited in known hot spots for fish kills, provided the data to show with certainty that most fish kills in the estuary were caused by low dissolved oxygen (hypoxia), in situations where wind mixed the bottom water up toward the surface causing fish to suffocate.

Impacts
This project provided a detailed assessment of trends in nutrient pollutant loadings to the Neuse Estuary over time, and has shown that water quality of the Neuse, indicated by total nitrogen loading, has not changed over the past ~12 years. The data should be of value to resource managers in illustrating the need for further actions to reduce nutrient loading to this estuary. The near-real-time, hourly data from this research also provided certainty in evaluating the cause of most major fish kills over the study period, eliminating the public anxiety that had previously accompanied fish kill assessment. The platform data from our website will continue to be used by our state environmental/ health agencies, and by many scientists and graduate students conducting thesis research (at several departments of NCSU as well as UNC and ECU). The data and website are also being used by students from grade schools, secondary schools, high schools and colleges to learn about water quality sampling and riverine/estuarine ecology.

Publications

• Burkholder, J.M. (2001) Eutrophication and oligotrophication, pp. 649-670. In: Encyclopedia of Biodiversity, Vol. 2, by Simon Levin (ed.). Academic Press, New York.
• Burkholder, J.M. (2002) Cyanobacteria, pp. 952-982. Invited, peer-reviewed contribution for the Encyclopedia of Environmental Microbiology, by G. Bitton (ed.). Wiley Publishers, New York.
• Burkholder, J.M., D.A. Dickey, C. Kinder, R.E. Reed, M.A. Mallin, G. Melia, M.R. McIver, L.B. Cahoon, C. Brownie, N. Deamer, J. Springer, H. Glasgow, D. Toms & J. Smith (2006) Comprehensive trend analysis of nutrients and related variables in a large eutrophic estuary: A decadal study of anthropogenic and climatic influences. Limnology & Oceanography.
• Burkholder, J., D. Eggleston, H. Glasgow, C. Brownie, R. Reed, G. Melia, C. Kinder, G. Janowitz, R. Corbett, M. Posey, T. Alphin, D. Toms, N. Deamer & J. Springer (2004) Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound. Proceedings of the National Academy of Sciences (USA) 101:9291-9296.
• Anderson, D.M., P.M. Glibert & J.M. Burkholder (2002) Harmful algal blooms and eutrophication: nutrient sources, composition, and consequences. Estuaries 25:704-726.
• Brownie, C., H.B. Glasgow, J.M. Burkholder, R.E. Reed & Y. Tang (2002) Re-evaluation of the relationship between Pfiesteria and estuarine fish kills. Ecosystems 6:1-10.
• Fan, C., P.M. Glibert & J.M. Burkholder (2003) Characterization of the affinity for nitrogen, uptake kinetics, and environmental relationships for Prorocentrum minimum in natural blooms and laboratory cultures. Harmful Algae 2:283-299.
• Glasgow, H.B., J.M. Burkholder, M.A. Mallin, N.J. Deamer-Melia & R.E. Reed (2001) Field ecology of toxic Pfiesteria complex species, and a conservative analysis of their role in estuarine fish kills. Environmental Health Perspectives 109:715-730.
• Glasgow, H.B., J.M. Burkholder, R.E. Reed, A.J. Lewitus & J.E. Kleinman (2004) Real-time remote monitoring of water quality: a review of current applications, and advancements in sensor, telemetry, and computing technologies. Journal of Experimental Marine Biology and Ecology 300:409-448.
• Glibert, P.M. and J.M. Burkholder (2006) The complex relationships between increasing fertilization of the Earth, coastal eutrophication, and HAB proliferation, chapter 24. In: The Ecology of Harmful Algae, by E. Graneli and J. Turner (eds.). Springer-Verlag, New York (in press).
• Reed, R.E., H.B. Glasgow, J.M. Burkholder, and C. Brownie (2004) Seasonal halocline structure, nutrient distributions, and acoustic Doppler current profiler flow patterns over multiple years in a shallow, stratified estuary. Estuarine and Coastal Shelf Science 60:549-566.
• Glibert, P.M., S. Seitzinger, C.A. Heil, J.M. Burkholder, M.W. Parrow, L.A. Codispoti and V. Kelly (2005) Eutrophication: new perspectives on its role in the global proliferation of harmful algal blooms. Oceanography 18:198-209.
• Mallin, M.A., J.M. Burkholder, L.B. Cahoon & M.H. Posey (2000) The North and South Carolina Coasts. In: The Seas at the Millennium, by C. Shepherd (ed.). Academic Press, New York. Also among several contributions selected from this multi-volume set, for publication in Marine Pollution Bulletin (vol. 41, pp. 56-75).
• Mallin, M.A., S.H. Ensign, D.C. Parsons, V.L. Johnson, J.M. Burkholder, and P.A. Rublee (2004) Relationship of Pfiesteria spp. and pfiesteria-like organisms to environmental factors in tidal creeks draining urbanized watersheds, pp. 68-70. In: Harmful Algae 2002 - Proceedings of the Xth International Conference on Harmful Algae, by K.A. Steidinger, J.A. Landsberg, C.R. Tomas & G.A. Vargo (eds.). Florida Fish & Wildlife Conservation Commission, Florida Institute of Oceanography, and the Intergovernmental Oceanographic Commission of UNESCO, St. Petersburg, FL.
• Rublee, P.A., J.W. Kempton, E.F. Schaefer, C. Allen, J.M. Burkholder, H.B. Glasgow, and D.W. Oldach (2001) Distribution of Pfiesteria sp. and an associated dinoflagellate along the U.S. East Coast during the active season in 1998 and 1999, pp. 89-91. In: Harmful Algal Blooms 2000, by G.M. Hallegraeff, S.I. Blackburn, C.J. Bolch & R.J. Lewis (eds.). IOC of UNESCO, Paris.
• Springer, J.J., J.M. Burkholder, P.M. Glibert, and R.E. Reed (2005) Use of a real-time remote monitoring network and shipborne sampling to characterize a dinoflagellate bloom in the Neuse Estuary, North Carolina, U.S.A. Harmful Algae 4:533-551.

Progress 10/01/03 to 09/30/04

Outputs
Impacts of Urban and Agricultural Pollution on Aquatic Communities 41. Progress We have continued our decadal monitoring and research study, ongoing, in the Neuse Estuary. Our objectives are to improve estimates for nutrient (nitrogen, phosphorus) loadings, including major characterization of the flow dynamics and flushing; to determine impacts of major storms on water quality and aquatic communities; to examine localized impacts of anthropogenic pollutants; and to enhance understanding of factors leading to fish kills. This ongoing project has yielded the most detailed long-term database in existence on the Neuse. The project has additionally been strengthened by data from a series of automated platform stations that are providing real-time data (hourly data over every 24-hour period) on the Neuse (1999-present). Our laboratory was the first to design and install such a system in North Carolina. It is yielding accurate, accessible data (at www.waterquality.ncsu.edu) on physical, chemical and biological water quality. The stations were strategically positioned in 'hot spots' for fish kills, oxygen deficits, and noxious/toxic algal blooms. The platform data from our website are intensively used by our state's environmental/health agencies, and by many scientists and graduate students conducting thesis research at NCSU, UNC, ECU, UNCG, UNCW. The data and website are also being used by students from grade schools, secondary schools, high schools and colleges to learn about water quality sampling and riverine/estuarine ecology. We are continuing to improve estimates of nutrient loadings and impacts from point and nonpoint sources, and are using acoustic Dopplar current profiling to obtain more accurate estimates for volume of flow. Based on our research in 2004, time series evaluations indicated that total nitrogen loading has not significantly changed over the past 11 years, and ammonia concentrations have increased by 700%. Our analyses continue to support the premise that an apparent 30% reduction in TN loading to the Neuse Estuary over the past five years occurred because a severe drought (2000-2002) temporarily reduced nonpoint source inputs. Nutrient reductions from improved management practices in the Neuse watershed have been offset by increases in human and swine populations and related factors. This analysis points to the need for targeting reductions in additional major urban and agricultural sources, to reduce nutrient pollution, algal blooms, and fish kills in the Neuse Estuary

Impacts
42. Impact / Significance This Neuse Estuary study is providing a more accurate assessment of trends in N and P loadings and major contributors to those loadings over time. Our automated platform data are providing the critical "before" conditions in fish kills, eliminating much of the guesswork about causality and public anxiety that had accompanied fish kill assessment. The ongoing effort will also improve evaluation of management strategies to reduce N loading to the Neuse by 30%, and will provide insights about additional pollution sources that should be targeted for reduction to improve water quality in the Neuse Estuary.

Publications

• Burkholder, J., D. Eggleston, H. Glasgow, C. Brownie, R. Reed, G. Melia, C. Kinder, G. Janowitz, R. Corbett, M. Posey, T. Alphin, D. Toms & N. Deamer (2004) Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound. Proceedings of the National Academy of Sciences (USA) 101:9291-9296.
• Glasgow, H.B., J.M. Burkholder, R.E. Reed, A.J. Lewitus & J.E. Kleinman (2004) Real-time remote monitoring of water quality: a review of current applications, and advancements in sensor, telemetry, and computing technologies. Journal of Experimental Marine Biology and Ecology 300:409-448.
• Reed, R.E., H.B. Glasgow, J.M. Burkholder & C. Brownie (2004) Seasonal halocline structure, nutrient distributions, and acoustic Doppler current profiler flow patterns over multiple years in a shallow, stratified estuary. Estuarine and Coastal Shelf Science 60:549-566.

Progress 10/01/02 to 09/30/03

Outputs
We continued our decadal monitoring and research study, ongoing, in the Neuse Estuary. Our objectives are to improve estimates for nutrient (nitrogen, phosphorus) loadings, including major characterization of the flow dynamics and flushing; to determine impacts of major storms on water quality and aquatic communities; to examine localized impacts of anthropogenic pollutants; and to enhance understanding of factors leading to fish kills. This ongoing project has yielded the most detailed long-term database in existence on the Neuse. The project has additionally been strengthened by data from a series of automated platform stations that are providing real-time data (hourly data over every 24-hour period) on the Neuse. Our laboratory was the first to design and install such a system in North Carolina. It is yielding accurate, and accessible data (at www.waterquality.ncsu.edu) on physical, chemical and biological water quality. The stations were strategically positioned in 'hot spots' for fish kills, oxygen deficits, and noxious/toxic algal blooms. The platform data from our website are intensively used by our state's environmental/ health agencies, and by many scientists and graduate students conducting thesis research (at several departments of NCSU as well as UNC and ECU). The data and website are also being used by students from grade schools, secondary schools, high schools and colleges to learn about water quality sampling and riverine/estuarine ecology. We are continuing to improve estimates of nutrient loadings and impacts from point and nonpoint sources. We are also continuing to use acoustic Dopplar current profiling to obtain more accurate estimates for volume of flow. Based on our research in 2003, time series evaluations spanning the past 10 years indicated that total nitrogen (N) significantly decreased by about 30% (statistically significant; P < 0.05); however, dissolved oxygen decreased by 1 mg/L and there was a 60% increase in ammonium loading. Our analysis supports the premise that an apparent 30% reduction in TN loading to the Neuse Estuary over the past five years occurred because a severe drought (2000-2002) temporarily reduced nonpoint source inputs. Nutrient reductions from improved management practices in the Neuse watershed have been offset by increases in human and swine populations and related factors. This analysis points to the need for targeting reductions in additional major urban and agricultural sources, to reduce nutrient pollution, algal blooms, and fish kills in the Neuse Estuary.

Impacts
This Neuse Estuary study is providing a more accurate assessment of trends in N and P loadings and major contributors to those loadings over time. Our automated platform data are providing the critical 'before' conditions in fish kills, eliminating much of the guesswork about causality and public anxiety that had accompanied fish kill assessment. The ongoing effort will also improve evaluation of management strategies to reduce N loading to the Neuse by 30%, and will provide insights about additional pollution sources that should be targeted for reduction to improve water quality in the Neuse Estuary. Two publications are in press from our 2003 research.

Publications

• No publications reported this period

Progress 10/01/01 to 09/30/02

Outputs
Our project objectives in the Neuse Estuary are to improve estimates for nutrient (nitrogen,phosphorus) loadings, including major characterization of the flow dynamics and flushing; to determine impacts of major storms on water quality and aquatic communities; to examine localized impacts of anthropogenic pollutants; and to enhance understanding of factors leading to fish kills. In 2002 we continued to assess impacts of water-column nitrate pollution on survival of North Carolina's most important seagrass for fish habitat, Zostera marina, and found that the effects of nitrate over-enrichment are exacerbated by elevated temperatures. In a second component of our project effort, we achieved a major milestone: analysis of long-term trends in nutrient loading to the Neuse Estuary, based on a decade of intensive sampling (weekly at 6 stations, biweekly at 18 stations, including both channel and side-channel stations) from 1993-2002. This ongoing project has yielded the most detailed long-term database in existence on the Neuse. The project has additionally been strengthened by data from a series of automated platform stations that are providing real-time data (hourly data over every 24-hour period) on the Neuse. Our laboratory was the first to design and install such a system in North Carolina. It is yielding much more accurate, and accessible data at www.pfiesteria.org) than were previously possible on physical, chemical and biological water quality. The stations were strategically positioned in `hot spots' for massive fish kills, oxygen deficits, noxious algal blooms, and toxic Pfiesteria outbreaks. The platform data from our website are intensively used by our state's environmental/ health agencies, and by many scientists and graduate students conducting thesis research (at several departments of NCSU as well as UNC and ECU). The data and website are also being used by students from grade schools, secondary schools, high schools and colleges to learn about water quality sampling and riverine/estuarine ecology. We are continuing to strengthen estimates of nutrient loadings and associated impacts, including both point (localized-sewage, swine wastes) and nonpoint pollution sources. We are also using acoustic Dopplar current profiling (ADCP, with bottom-tracking capability) to obtain much more accurate estimates for volume of flow than previously were possible, and in 2002 we completed construction of composite visualizations of flow dynamics, entering and leaving the estuary from surface to bottom water, from the single-transect data and ADCP Based on our research in 2002, time series evaluations spanning the past 10 years indicated that suspended solids and total Kjeldahl nitrogen (N) significantly decreased by about 25% (statistically significant; P < 0.05). Total phosphorus (P), nitrate (form of inorganic N), and chlorophyll a qualitatively increased (by about 35%) but these trends were not statistically significant. There was a significant increase in ammonium (second form of inorganic N) system-wide, by about 400%. The decadal analysis also included examination of potential drivers of these trends such as changes in land use and waste input.

Impacts
This study has strengthened understanding about how nutrient pollution and warming trends in global climate change will affect our State's critical seagrass habitat for commercially valuable marine fisheries. In addition, this Neuse Estuary study is providing a more accurate assessment of trends in N and P loadings and major contributors to those loadings over time. Our automated platform data are providing the critical, 'before' conditions in fish kills, eliminating much of the guesswork about causality and public anxiety that had accompanied fish kill assessment. The ongoing effort will also improve evaluation of management strategies to reduce N loading to the Neuse by 30%.

Publications

• Anderson, D.M., P.M. Glibert & J.M. Burkholder. 2002. Harmful algal blooms and eutrophication: nutrient sources, composition, and consequences. Estuaries 25:704-726.
• Brownie, C., H.B. Glasgow, J.M. Burkholder, R.E. Reed & Y. Tang. 2002. Re-evaluation of the relation-ship between Pfiesteria and estuarine fish kills. Ecosystems 5.
• Burkholder, J.M. 2002. Cyanobacteria, pp. 952-982. Invited, peer-reviewed chapter in: Encyclopedia of Environmental Microbiology, by G. Bitton (ed.). Wiley Publishers, New York.
• Touchette, B.W. & J.M. Burkholder. 2002. Seasonal variations in carbon and nitrogen constituents in eelgrass (Zostera marina L.) as influenced by increased temperature and water-column nitrate. Botanica Marina 45:23-34.

Progress 10/01/00 to 09/30/01

Outputs
The project objectives in the Neuse Estuary are to improve estimates for nutrient (nitrogen, phosphorus) loadings, including major characterization of the flow dynamics and flushing; to determine impacts of major storms on water quality and aquatic communities; to examine localized impacts of anthropogenic pollutants; and to enhance understanding of factors leading to fish kills. Our laboratory was the first to design and install a series of automated platform stations that are providing real-time data for surface waters of this state. The system, installed on the Neuse, yields much more accurate, detailed (hourly data over every 24-hour period), and accessible data (via a publicly accessed website, www.pfiesteria.org) than were ever previously possible on physical, chemical and biological water quality. The stations were strategically positioned in `hot spots' for massive fish kills, oxygen deficits, noxious algal blooms, and toxic Pfiesteria outbreaks. The platform data from our website are intensively used by our state's environmental/health agencies, and by many scientists and graduate students conducting thesis research (at several departments of NCSU as well as UNC and ECU). The data and website are also being used by students from grade schools, secondary schools, and colleges to learn about water quality sampling and riverine/estuarine ecology. We also have been characterizing seasonal differences in buoyancy plumes affecting the hydrographic structure of the estuary, based on our comprehensive nine-year (ongoing) physical/chemical database. The database was developed from weekly to biweekly sampling of ca. 20 stations for more than 40 variables throughout the entire water column, considering side-channel as well as mid-channel data. Side channel locations are especially important because in those areas algal blooms develop and become concentrated by prevailing winds; moreover, side-channel locations are associated with the worst oxygen deficits in the estuary, and with high nutrient inputs from groundwater. We are continuing to strengthen estimates of nutrient loadings and associated impacts, including both point (localized - sewage, swine wastes) and nonpoint pollution sources. We are also using acoustic Dopplar current profiling (ADCP, with bottom-tracking capability) to obtain much more accurate estimates for volume of flow than previously were possible. We constructed composite visualizations of flow dynamics from the single-transect data and ADCP. The analysis revealed a classical estuarine circulation pattern of outflow at the surface/southern shore and inflow at the bottom/northern shore. Wind fields, hurricanes, and small-scale, high-precipitation events represented significant forcing variables. From our detailed database on nutrient concentra-tions and volume of flow, we have determined that N loading to the Neuse Estuary has significantly increased (total N up by ca. 20%; total inorganic N up by nearly 40%), and P loading has decreased (down by ca. 12%) over the past nine years (including the duration of this study). These N and P loadings are about 20% higher than previous, less accurate estimates.

Impacts
Our automated platform data are providing the critical "before" conditions in fish kills, eliminating much of the guesswork about causality and public anxiety that had accompanied fish kill assessment. They are also providing more accurate nutrient loading data. State policy has targeted a 30% reduction in N loading to this estuary over the next five years, but the target assumes a beginning level of loading based on mid-channel, monthly data. This intensive, long-term study has shown that the previous approach has underestimated N loading by 20%. Thus, the targeted goal should be increased, with associated shifts in management strategies required to meet that goal.

Publications

• No publications reported this period

Progress 10/01/99 to 09/30/00

Outputs
The project objectives in the Neuse Estuary were to improve estimates for nitrogen and phosphorus loadings; to determine impacts of major storms on water quality and aquatic communities; to examine localized impacts of anthropogenic pollutants; and to enhance understanding of factors leading to fish kills. We intensively sampled the Neuse (weekly; more frequently during storm events) at ca. 20 stations for > 40 variables. Rather than focusing only on mid-channel locations (with monthly sampling) as in previous studies, we also sampled the sides of the main channel which are the areas where algal blooms and fish kills typically occur and become concentrated by prevailing winds. The data enabled improved estimates of nutrient concentrations and associated impacts, including localized sources of pollution (sewage, swine wastes) to certain sampling sites. We also completed cross-estuary transects with acoustic Dopplar current profiling to obtain much more accurate volume-of-flow data than previously were possible. From the detailed database on nutrient concentrations and volume of flow, we determined that N loading to the Neuse Estuary has significantly increased (total N up by ca. 20%; total inorganic N up by nearly 40%), and P loading has decreased (down by ca. 12%) over the past 8 years (including the duration of this study). These N and P loadings to this estuary were ca. 20% higher than previous estimates. This study also enabled analysis of comparative impacts on the Neuse from several hurricane-level storms. Hurricane Fran, with low flooding and high (relatively undiluted) pollutant loadings, was much more damaging to fish populations than Hurricane Floyd/ associated storms. The latter events caused major floods and high dilution of pollutants, most of which settled out in the freshwater river and estuary and did not reach Pamlico Sound. Reports by certain scientists of a `dead zone' in Pamlico Sound were without basis. Low-oxygen bottom water was in part of the sound for 1-2 weeks but the overlying, oxygen-replete water provided refuge habitat for most fish. Fish disease occurred in both the estuary and the sound (likely from stress due to sudden salinity change), but disease incidence subsided within ca. 8 weeks post-Floyd, and only six dead crabs were reported throughout the entire Neuse/Pamlico Sound expanse. In contrast, many millions of fish died post-Fran in anoxic river and estuarine waters. A beneficial effect of such major storms was to depress toxic activity of toxic Pfiesteria. We installed a series of 15 automated platform stations on the Neuse Estuary from east of New Bern down to the western edge of Pamlico Sound, with funding to instrument 7 stations thus far. The stations are positioned in `hot spots' for fish kills, algal blooms, and toxic Pfiesteria. They send real-time data hourly to a website where data summaries are accessible to scientists, managers, teachers and their classes, and other interested citizens (>450,000 hits per month during `fish kill' season). The automated stations enable us to obtain data before as well as during/after fish-kills to strengthen insights about causative factor(s).

Impacts
North Carolina state policy has targeted a 30% reduction in nitrogen loading to the Neuse Estuary over the next five years, but the target assumes a beginning level of nutrient loading that was based on mid-channel, monthly data. This intensive, long-term study has shown that mid-channel sites are not where algal blooms and most nutrient inputs occur; and that the previous approach has underestimated N loading by 20%. Thus, the targeted goal needs to be increased to 50% reduction in N loading, with associated shifts in the management strategies that will be required to meet that goal.

Publications

• No publications reported this period