Teach with Data

About Our Science and Data

The health of every reserve is continuously monitored by the Research Reserve System’s System-wide Monitoring Program, or SWMP (pronounced “swamp”). These measurements provide a record of how human activities and natural events and fluctuations affect coastal habitats

Students can query the database and work with real estuary monitoring data in the problem-solving exercises provided within the Estuary Education Resources. These interactive activities share how the data is used and the ongoing monitoring and research taking place at each reserve.

All SWMP data are served through the reserve system's Centralized Data Management Office, which is housed at the North Inlet-Winyah Bay reserve in South Carolina. The data management office provides quality assurance and control and is responsible for maintaining and updating the standard operating procedures. To query data, use the SWMP Graphing and Export System.

Reserve monitoring data have three major components:

Abiotic indicators of water quality and weather. Parameters include nutrients, temperature, salinity, pH, dissolved oxygen, and in some cases, contaminants.
Biological monitoring. Includes measures of biodiversity, habitat, and population characteristics.
Watershed, habitat, and land use mapping. Provides information on types of land use by humans and changes in land cover associated with each reserve.

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Data Collection Details

Each reserve approaches data collection the same way. Water quality data are collected at four stations at 15-minute intervals. Weather data are collected every 5 seconds and averaged every 15 minutes. Biological monitoring data (specifically chlorophyll a) and nutrient data are collected at each reserve’s four water quality stations on a monthly basis over a 24-hour period.

SWMP station at a National Estuarine Research Reserve

Data Parameters

Water Quality Parameters

The data-monitoring program uses automated data loggers to monitor the temperature, depth, salinity, dissolved oxygen, turbidity, and pH of each estuary’s water, key indicators of water quality and environmental conditions. The reserves also sample the water for nutrients (nitrogen and phosphorus) and chlorophyll on a monthly basis. Nutrient monitoring is important because there is a positive relationship between the concentration of nutrients in the water and the rate of primary production, which is an indicator of the growth and biomass of algae or phytoplankton.

Download Our Water Quality Cheatsheet - PDF

Explore Definitions:

Weather Parameters

Weather conditions can have a strong influence on water quality. For example, rainfall influences salinity in estuaries and can increase runoff of sediment and organic material that in turn may influence other parameters such as dissolved oxygen, nutrient concentrations, turbidity, pH, and temperature.

Explore Definitions:

Barometric Pressure

Barometric pressure (air pressure) is the weight of the overlying air on the Earth. Low barometric pressure means that overlying air is rising, whereas high pressure means the overlying air is sinking.

A barometer is the tool used to measure barometric pressure. It consists of a glass tube that is closed at one end and open at the other. The tube sits vertically, with the open end sitting in a pool of mercury. Changes in pressure will change the level of mercury in the tube. Increased air pressure pushes the mercury higher into the tube, whereas decreased air pressure allows the mercury in the tube to drop.

Barometric pressure has important effects on water chemistry and weather conditions. Barometric pressure affects the amount of gas that can dissolve in water. More gas, such as oxygen, can dissolve in water under higher barometric pressure than under lower barometric pressure. For instance, more oxygen is dissolved in water at sea level than at high altitudes. When it comes to weather, high barometric pressure supports sunny, clear, and favorable conditions. Low barometric pressure promotes rainy and cloudy weather conditions. Barometric pressure has been used for hundreds of years to forecast weather.
Relative Humidity

Relative humidity is a measure of the amount of moisture in the air relative to the total amount of moisture that the air can hold. For instance, a relative humidity of 50% means the air is only half saturated with moisture. Warmer air can hold more moisture than cooler air.

The reserves use a capacitance-type sensor to measure relative humidity. Changes in relative humidity cause the shape of the sensor to change. When the sensor changes shape, its capacitance, or ability to store an electrical charge, changes in a detectable and repeatable fashion. Humidity is simply water vapor in the air, which is needed to form rain. Additionally, water vapor holds heat in the air. It is a greenhouse gas, which means it is a gas that absorbs heat and warms the atmosphere. This is why humid air feels warmer.
Wind Speed

Wind speed describes how fast the air is moving past a certain point. This may be averaged over a given unit of time, such as miles per hour, or an instantaneous speed, which is reported as a peak wind speed, wind gust, or squall. Measuring wind speed is usually done using a cup or propeller anemometer, an instrument with three cups or propellers on a vertical axis. The force of the wind causes the cups or propellers to spin. The spinning rate is proportional to the wind speed.

Wind speed is important for monitoring and predicting weather patterns and global climate. Wind speed has numerous impacts on surface water. This parameter affects the rate of evaporation, mixing of surface waters, and the development of seiches and storm surges. This process has a dramatic effect on water quality and water level.
Wind Direction

Photo Credit: Jeremiah Ets-Hokin

Wind direction describes the direction on a compass from which the wind emanates and is measured by a wind vane that aligns itself with the direction of the wind.

Wind direction is important for monitoring and predicting weather patterns and global climate. Wind direction has numerous impacts on surface water, affecting the rate of evaporation, mixing of surface waters, and the development of seiches and storm surges. These changes in the water cycle, water circulation in an estuary, and weather patterns have dramatic effects on water quality and water levels.
Precipitation

Precipitation is any form of water that falls to the Earth’s surface, including snow, rain, sleet, freezing rain, and hail.

Precipitation can be measured in numerous ways. SWMP uses what is known as a “tipping bucket rain gauge.” This tool uses a small cup that fills with precipitation. When the cup is full, it will tip and empty. A counter tracks how many times the cup tips, and after a certain time interval, this number is converted to a precipitation measurement in millimeters. Heated tipping bucket rain gauges allow the measurement of snow and sleet.

Precipitation is needed to replenish water to the earth. Without precipitation, this planet would be an enormous desert. The amount and duration of precipitation events affect both water level and water quality within an estuary. Precipitation supplies freshwater to an estuary, which is an important source of dissolved oxygen and nutrients.
Air Temperature

Air temperature is a measure of how hot or cold the air is. Temperature can be measured in numerous ways, including thermistors, thermocouples, and mercury thermometers. SWMP uses thermistors, metallic devices that undergo predictable changes in resistance in response to changes in temperature. This resistance is measured and converted to a temperature reading in Celsius, Fahrenheit, or Kelvin.

Air temperature affects the growth and reproduction of plants and animals, with warmer temperatures promoting biological growth. Air temperature also affects nearly all other weather parameters, including the rate of evaporation, relative humidity, wind speed and direction, and precipitation patterns and types (snow, sleet, or rain).
Solar Radiation

Solar radiation is the amount of light available for photosynthesis. Solar radiation or photosynthetically active radiation (PAR) is the amount of light in the 400 to 700 nanometer wavelength range, which is what plants use for photosynthesis.

Solar radiation is measured by a silicon photovoltaic detector. This detector measures light in the 400 to 700 nanometer range. Higher solar radiation promotes plant growth.

Collection Methods

Water Quality Data

Photo of a person in a boat looking at a data logger — Data logger from Kachemak Bay NERR

Each reserve has a minimum of four water-quality stations installed at points that cross an environmental gradient for the purpose of detecting both long-term and short term changes in water quality at each reserve. Reserve staff members download data from each station about every two weeks, conduct preliminary analyses to check for data quality, and then transmit the data to the reserve system’s Centralized Data Management Office. Some data loggers also use telemetry to transmit the data directly via a satellite link. Basic water quality parameters measured at each station: water temperature, depth, salinity, pH, dissolved oxygen, and turbidity (cloudiness or clarity).

Weather Data

Photo of a weather station on a sunny day — Weather station at a National Estuarine Research Reserve

Each reserve has one or more weather stations that collect data every 5 seconds and report an average of every 15 minutes for air temperature, wind speed and direction, relative humidity, barometric pressure, rainfall, and photosynthetically active radiation (PAR). Weather stations have sensors placed high in the air to collect atmospheric data. SWMP instruments are left in place during natural disasters and are often able to collect data during hurricanes, etc. Data Mystery activities allow exploration of these extreme weather events. In northern reserves, these monitoring instruments may be removed when water is expected to freeze over. This can create gaps in the weather data collection for those reserves.

Nutrient Data

Nutrients are also monitored at each reserve. Each reserve collects water samples on a monthly basis to measure the concentration of nutrients (e.g., ammonium, nitrate, nitrite, orthophosphate) at each station. Each reserve has at least one water quality monitoring station where nutrient samples are collected over a 24-hour period to determine how nutrient concentrations change over a day/night cycle and over tidal cycles.

Data Citation

For data generated from the SWMP graphing tool to be used in a publication, please use the following citation:

National Oceanic and Atmospheric Administration, Office for Coastal Management, National Estuarine Research Reserve System-wide Monitoring Program. [Date.] Centralized Data Management Office, Baruch Marine Field Lab, University of South Carolina. Accessed at cdmo.baruch.sc.edu.