Nutrients & Nutrient Impacts
Priorities for Productive Marine Ecosystems
Sunset over a coastal marsh. Photo credit: Gulf of Mexico Alliance Governors' Action Plan
The determination of healthy levels of nutrients is an important step toward reducing their impact, and providing vital management tools. Establishing nutrient criteria for coastal waters and estuaries could improve their quality and productivity, but the challenge is to eliminate only the excess nutrients while maintaining adequate levels to ensure ecosystem productivity. The Alliance is providing a collaborative approach to build and evaluate tools needed to reduce excess nutrients and restore coastal waters that have been negatively impacted by nutrients.
- Design a regional process for comparing nutrient criteria across coastal and estuarine waters
- Develop and implement strategies that reduce nutrient inputs and hypoxia
- Establish a comprehensive ecosystem approach to manage nutrient inputs and reduce impacts to coastal ecosystems
- Increase the capacity of Gulf coastal communities so that nutrient impacts are better managed and reduced
Nutrients 1: Nutrient Characterization
Action: Implement regional nutrient characterization studies to evaluate ecosystem responses and to develop the tools for better characterization of nutrients in coastal waters.
Benthic Index of Biotic Integrity for Estuarine and Near-coastal Waters
The GOMA Nutrients Team developed a benthic Index of Biological Integrity (IBI) for estuarine and near-coastal waters of the Gulf of Mexico using benthic invertebrate data from National Coastal Assessment sampling efforts. This biological indicator will assist in investigation of linkages among the benthic biological community structure, intermediate stressors, and nutrient concentrations. A classification system was developed for different zones and site classes in the Gulf of Mexico coastal waters. The progress made was toward development of biological endpoints that will contribute to evidence based development of nutrient criteria for these waters. The work completed under this project is available to be used as information for the GOMA sources, fate and transport studies done in the Gulf and will be useful to the Gulf States as nutrient criteria development activities continue.
Nutrients 2: Nutrient Criteria Development
Action: Identify common state needs and priorities for the development of nutrient criteria and provide support and technical assistance to facilitate a regional approach to nutrient criteria development and management.
Pilot Nutrient Criteria Development
This pilot project characterizes the nutrient dynamics in the Mission-Aransas estuary in terms of their sources, transport, fate and effects. The project will provide a more complete understanding of the relationships between freshwater inflow, nutrients, physical processes, and biological communities with the goal of developing nutrient criteria for coastal ecosystems of the Western Gulf of Mexico (GOM).
Results from the first year of study clearly show the importance of storms in delivering nitrogen, phosphorus, and organic matter to Copano Bay. Nutrients delivered during a September 2010 storm resulted in elevated nitrogen and phosphorus concentrations for a month during the storm was removed by denitrification. Six months later nitrogen concentrations in the bay were low enough that we measured nitrogen fixation, suggesting a strong demand for nitrogen. Ongoing sampling will provide insight into nutrient dynamics during drought conditions.
Dr. Ed Buskey
Nutrients 3: Hypoxia
Action: Coordinate strategies and provide guidance to better characterize hypoxia and the resulting socioeconomic impacts.
A Primer on Hypoxia in the Gulf of Mexico
Released during the Gulf of Mexico Hypoxia Research Coordination Workshop held in Bay St. Louis in April 2011, the Primer on Hypoxia in the Gulf of Mexico is a product of last year's Hypoxia Coordination Workshop sponsored by the Northern Gulf Institute, Mississippi State University, Dauphin Island Sea Lab, Louisiana State University, Florida State University and the University of Southern Mississippi. The Gulf of Mexico Alliance and the Gulf of Mexico Hypoxia Task Force also participated in the conference. In addition to addressing the Alliance Nutrients Team's action items, the Primer also supports the goals and actions of the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force identified in the Gulf Hypoxia Action Plan. It uses existing communication networks to increase awareness of hypoxia, its causes and its impacts to stakeholders, coastal managers and decision makers, as well as the general public.
Nutrients 4: Nutrient Reduction Strategies
Action: Develop management tools and implement nutrient reduction activities in cooperation with local communities to reduce excess nutrient inputs to estuaries and coastal waters.
Decision Support Toolbox
Establishing nutrient criteria for coastal waters and estuaries could improve their quality and productivity, but the challenge is to eliminate only the excess nutrients while maintaining adequate levels to ensure ecosystem productivity. The purpose of the Nutrient Reduction Decision Support Toolbox is to increase knowledge of nutrient runoff and to inform and improve policy decisions as well as building the capacity to respond to change and challenges among Gulf Decision makers. The toolbox originated from the Alliance’s Nutrient Reduction priority issue team and its initiatives to reduce the size of the hypoxic zone in the Gulf of Mexico as well as occurrences of hypoxic events across Gulf of Mexico coastal and estuarine waters. The program is intended for use by state and local agencies and other organizations interested in reducing nutrients (nitrogen and phosphorus) and other pollutants to our water bodies in an effort to reduce Gulf hypoxia.
Low-Tech Nutrient Reduction
The determination of healthy levels of nutrients is an important step toward reducing their impact, and providing vital management tools. Establishing nutrient criteria for coastal waters and estuaries could improve their quality and productivity, but the challenge is to eliminate only the excess nutrients while maintaining adequate levels to ensure ecosystem productivity. The Low-technology Nutrient Reduction Strategies Evaluation provides a collaborative approach to evaluating low-technology water management structures to reduce excess nutrients leaving farm fields during storm water events that ultimately drain to the Mississippi River and the Gulf of Mexico.
Mississippi Delta Nutrient Reduction
Implementation of the Mississippi Delta Nutrient Reduction Strategies began in December 2009. This effort illustrates the progress that can be made to reduce nutrients when stakeholders work together to achieve shared goals of an improved environment, sustained economy, and enhanced quality of life.
To date, progress highlights of the implementation include:
• The Delta is being targeted as part of a state-wide survey to determine stakeholder knowledge and attitudes about excess nutrients.
• Tailwater recovery/on-site storage systems are being implemented and water conservation practices are being documented through collaboration of the implementation team.
• Sediment, total nitrogen, and total phosphorus reductions over the past two decades because of sediment and water management practices are being documented in Steele Bayou, a MRBI Priority Watershed in the Delta.
• Total nitrogen reduction through low-head weirs and riparian buffers is being documented in Delta watersheds.
• A system of tiered monitoring sites has been established in the Delta to evaluate the success of implementation through watershed projects and Mississippi River Basin Initiative.
• A web-based compendium of Mississippi water quality data from Mississippi DEQ, US Geological Survey, and US Army Corps of Engineers is complete and available at http://www.deq.state.ms.us.
Kay Whittington and Trey Cooke
Nutrient Reduction in St. Louis Bay
The NASA Applied Science & Technology Project Office at Stennis Space Center (SSC) is using satellites, in-situ measurements and computational modeling to study relationships between water quality in St. Louis Bay, Mississippi and the watershed characteristics of the Jourdan and Wolf rivers from 2000-2010.
This in-situ data was used to develop, assess and validate satellite data products. In phase one, existing data sets were processed to estimate parameters of interest such as chlorophyll a, total suspended solids, and colored dissolved organic matter. In phase two, spatial and temporal analysis techniques were used to examine relationships between the watershed and St. Louis Bay water quality characteristics. In the final phase, BASINS/HSPF analysis is being performed on the data to provide parameter values for water quality studies. This information will provide the basis to determine effective strategies to reduce nutrients into the Bay of St. Louis.
Smart Yard Healthy Gulf Campaign
Developed by a partnership between the Education and Nutrient Priority Issue Teams, Smart Yard, Healthy Gulf is a new public education campaign designed to reduce fertilizers entering local waters by helping people make responsible lawn fertilizer decisions. Applying the proper amount of fertilizer at the proper time(s) of the growing season keeps lawns looking vibrant. It can save time and money. Not only will lawns be something to be proud of, but the Gulf of Mexico will be more resilient and healthy, including Gulf seafood!
Ann Porter and Lee Yokel