An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Ecology of Harmful Algal Blooms Publications

1. An approach to developing numeric water quality criteria for coastal waters: a transition from Sea WiFS to MODIS and MERIS satellitesThis study first provided an approach for developing numeric water quality criteria for coastal waters based on archived SeaWiFS ocean color satellite data. Second, this study developed an approach for transferring water quality criteria assessments to newer ocean color satellites, such as MODIS and MERIS. 

2. An exploratory analysis of Indiana and Illinois biotic assemblage data in support of state nutrient criteria developmentThis report conducted exploratory analyses of state datasets from Illinois and Indiana to determine threshold values for nutrients and chlorophyll a that can guide Indiana and Illinois criteria development.

3. A screening-level modeling approach to estimate nitrogen loading and standard exceedance risk, with application to the Tippecanoe River watershed, Indiana. This paper presents a screening-level modeling approach that can be used to rapidly estimate nutrient loading, assess numerical nutrient standard exceedance risk of surface waters, and explore best management practice (BMP) implementation to reduce loading with a relatively low data requirement. 

4. Assessment of satellite derived diffuse attenuation coefficients and euphotic depths in South Florida coastal watersOptical data was collected in the coastal waters off South Florida and the Caribbean Sea to evaluate products.

5. Carbon dynamics and export from flooded wetlands: A modeling approach. This paper covers the development and validation of a process based model for carbon cycling in flooded wetlands, called WetQual-C.

6. Ecological engineering practices for the reduction of excess N in human influenced landscapes: A guide for watershed managersThis paper describes seven ecological engineering practices known to decrease N to help watershed managers select the most effective techniques from among the following approaches: advanced-treatment septic systems, low-impact development structures, permeable reactive barriers, treatment wetlands, riparian buffers, artificial lakes and reservoirs, and stream restoration.

7. Effect of Temperature and Nutrient Manipulations on eelgrass Zostera marina L. from the Pacific Northwest, USA. Pacific Northwest Z. marina’s response to interactive effects of temperature and nitrogen conditions was experimentally evaluated. 

8. Effects of road salts on groundwater and surface water dynamics of sodium and chloride in an urban restored streamRoad salts are a growing environmental concern in urban watersheds. This paper examines groundwater and surface water dynamics of Na+ and Cl in Minebank Run, an urban stream in Maryland, USA. 

9. Effects of urban stream burial on nitrogen uptake and ecosystem metabolism: implications for watershed nitrogen and carbon fluxesUrbanization has resulted in the extensive burial and channelization of headwater streams, yet little is known about the impacts of stream burial on ecosystem functions critical for reducing downstream nitrogen (N) and carbon (C) exports. In order to characterize the biogeochemical effects of stream burial on N and C, researchers measured NO3  uptake and gross primary productivity and ecosystem respiration.

10. Filtration recovery of extracellular DNA from water sample under the influence of filter and environmental water properties (subscription only). This study examines the impact of filters (types and pore sizes) and physiochemical properties of surface water samples on the recovery of spiked DNA in water samples. 

11. How Do Land-Use and Climate Change Affect Watershed Health? A Scenario-Based Analysis (subscription only). In this study, impacts of several projected land-use and climate change scenarios on the health of the Wildcat Creek watershed in Indiana were assessed through three risk indicators, reliability–resilience–vulnerability (R–R–V). 

12. Hydrologic Controls on Nitrogen and Phosphorous Dynamics in Relict Oxbow Wetlands Adjacent to an Urban Restored Stream (subscription only).Although wetlands are known to be sinks for nitrogen and phosphorus, their function in urban watersheds remains unclear. This study analyzed water and nitrate and phosphate dynamics during precipitation events in two oxbow wetlands that were created during geomorphic stream restoration in Baltimore County, Maryland. 

13. Modeled summer background concentration nutrients and suspended sediment in the mid-continent (USA) great rivers. Regression models were used to predict summer background concentration of total nitrogen, total phosphorus, and total suspended solids, in the mid-continent great rivers: the Upper Mississippi, the Lower Missouri, and the Ohio.

14. Modeling Nitrogen Fate and Transport at the Sediment-Water Interface. Book chapter in Modeling and Simulation of Diffusive Processes: Simulation Foundations, Methods and Applications.

15. On the scaling behavior of reliability–resilience–vulnerability indices in agricultural watersheds. Risk indices such as reliability–resilience–vulnerability (R–R–V) have been proposed to assess watershed health. In this study, the spatial scaling behavior of R–R–V indices has been explored for five agricultural watersheds in the midwestern United States. 

16. Science and management of the introduced seagrass Zostera japonica in North America (subscription only). The introduced seagrass Zostera japonica is considered by some invasive, while others consider it benign. This report describes the management dynamics in North America and highlights the science and policies behind these decisions. 

17. Seasonal and interannual patterns in primary production, respiration and net ecosystem metabolism in three estuaries in the northeast Gulf of Mexico. Gross primary production, ecosystem respiration, and net ecosystem metabolism were calculated using date on three Gulf of Mexico estuaries. 

18. Utilizing Depth of Colonization of Seagrasses to Develop Numeric Water Quality Criteria for Florida Estuaries. EPA is working with state and local partners in Florida to develop numeric water quality criteria to protect estuaries from nutrient pollution.