Hydrological drivers, weather and climate conditions, and seasonal biological and biogeochemical transitions are important drivers and indicators of aquatic ecosystem function. To better understand these processes, the NEON project collects data at 34 freshwater aquatic field sites located across the United States:
- 24 wadeable streams
- 7 lakes
- 3 non-wadeable rivers
Field site locations are representative of aquatic features and habitats typical of regions across the United States within each NEON domain (excluding D20: Pacific Tropical, which has no aquatic sites) and near to NEON terrestrial field sites whenever feasible. Twenty of the aquatic sites are “core” sites meaning they will collect data for the 30-year lifetime of the observatory. The other 14 “relocatable” sites may move throughout the lifetime of the observatory. All NEON data are open access and available online.
At each aquatic field site, the NEON project collects data to understand changes in climate, hydrology, biogeochemical processes, organismal populations, and habitat structure.
Three collection systems are used to collect the data:
- Automated instruments that collect data year round
- Observational sampling periodically collected by field scientists
- Airborne remote sensing surveys that are scheduled every 3-5 years
The data collected through these three systems (automated instruments, observational sampling and airborne remote sensing) can be studied in conjunction with one another because they’re gathered in close proximity to each other at a site. The data are also comparable among field sites so researchers can study connections and patterns across ecosystems, and then develop models to forecast environmental change locally, regionally and at a continental scale. All NEON data collected at field sites are open access and freely available online.
The Power of Co-location
NEON collects automated instrument measurements, remote sensing data, field observations and samples in close proximity to each other and at different temporal scales. These activities allow for the quantification of ecological parameters and the detection of trends in and around water bodies.
In addition, many NEON aquatic sites are co-located with NEON terrestrial sites to allow for additional study of relationships between aquatic and terrestrial ecosystems. Some NEON sites are also located near other long-term ecological research areas (e.g., Toolik Lake and Konza Prairie) to leverage those areas’ existing infrastructure and long-term datasets
How NEON Extends Freshwater Aquatic Research Studies
A unique feature of the NEON project design is that the data collection approach is standardized across all aquatic field sites to allow for across-site comparisons of data. The collection methods also complement local, state, and national aquatic monitoring programs, such as the National Water Quality Assessment (NAWQA), a program of the U.S. Geological Survey (USGS), and the National Rivers and Streams Assessment (NRSA) and the NAtional Lakes Assessment program (NLA), a program of the U.S. Environmental Protection Agency (EPA). Together, NEON and existing environmental monitoring programs will enable a more holistic understanding of aquatic ecosystems. In addition to providing open access data and archival samples, NEON also serves as an infrastructure that researchers may leverage to conduct experiments and collect additional types of data.
Types of Aquatic Sites
NEON wadeable streams are defined as stretches of flowing water that are safely wadeable during most, if not all, of the year. Ideal NEON stream reaches have a 1 km permitted length that is free of major flow obstructions or major tributaries. The length of this reach allows for the wide range of biological, chemical, and physical parameters to be collected and to best capture within stream diversity across multiple habitat types (i.e., pools, riffles, and runs).
NEON non-wadeable rivers are defined as stretches of flowing water that are not often, if ever, safely wadeable. NEON river sites were chosen to allow year-round access to a 1 km reach for field measurement and sampling similar to streams. Each river site must have representative shoreline characteristics of the region and also accommodate the placement of a buoy in a location that captures the main flow, but is outside of navigation channels.
NEON lakes are defined as lentic bodies of water that may stratify for some period of time during the year. NEON lake sites have representative characteristics of the region they are located in, relative to size, hydrologic flow (i.e. seepage vs flow-through), and shoreline characteristics, with a minimum area of 5 acres and depth of 3 meters. Each lake must also accommodate the placement of a buoy that can be continuously accessed in the deepest basin during ice-free periods.
Core and Relocatable Aquatic Sites
In addition to being classified as stream, river or lake sites, NEON aquatic sites are also divided into core and relocatable sites. Data collection methods across core and relocatable aquatic sites are standardized and comparable. The difference between core and relocatable aquatic sites are as follows:
- Core sites are located in areas that are not significantly influenced by built structures (e.g., bridges, or human activities that may impact water quality, such as urbanization, agriculture, or wastewater effluent). These sites are designed to collect data for the 30-year lifetime of the project and are representative of ecosystem characteristics of the NEON domain they are located within (e.g., the Northeast, the Tundra).
- Relocatable site locations are often selected to capture specific environmental gradients (e.g., Domain 08 where a hydrologic continuum from headwater stream to large river was chosen) for a period of time and may be moved to study different gradients throughout the lifetime of the project.
Types of Data Collection at Aquatic Sites
Instruments and observational sampling methods are standardized across aquatic sites but vary slightly depending on the type of site (i.e., river, stream, lake). The table below illustrates types of sampling/instruments by aquatic site type.
Automated instruments are deployed in locations that are likely to (1) capture as much variability as possible; and (2) provide measurements with sufficient temporal resolution to capture trends over the lifetime of the observatory.
The NEON Aquatic Instrument System (AIS) collects information about physical and chemical properties of freshwater aquatic water bodies, the surrounding atmosphere, and adjacent riparian areas. These instruments are capable of collecting information at limited spatial scales but with high temporal resolution (many measurements per hour). Instruments measure meteorological conditions near aquatic water bodies and in-situ sensors measure water quality parameters to allow direct integration and extrapolation between measurements.
The Aquatic Instrument System (AIS) is comprised of three primary sensor arrays that collect the following data:
Additional Automated Instruments
- Meteorological Stations: Collect weather and climate data that are comparable to meteorological data collected at terrestrial field sites.
- Phenocam: Image data collected by the phenocam may be used for qualitative estimates of snow cover, riparian characteristics, or weather.
Field ecologists for the NEON project follow standardized, nationwide sampling protocols to enable direct comparison among sites and between types of data over the lifetime of the NEON project. NEON’s observational sampling approach was selected to include organisms from representative aquatic habitats with varying lifespans and trophic positions.
The Aquatic Observations System (AOS) includes field sampling protocols for:
- Aquatic organisms
- Aquatic microbes (surface water and benthic)
- Aquatic plants, macroalgae, bryophytes and lichens
- Macroinvertebrates and zooplankton
- Periphyton and phytoplankton
- Water and Particulates
- Physical Aquatic
- Bathymetry and stream morphology
- Riparian canopy identification and assessment
- Secchi depth and depth profiles
The NEON Airborne Observation team conducts remote sensing surveys of most aquatic sites every 3-5 years collecting a variety of data including:
- Lidar (discrete and waveform)
- Digital camera imagery
Accessing NEON Aquatic Data and Using NEON Infrastructure
NEON data are open access and freely available via the NEON Data Portal. Archival samples are also available upon request. Data from all field sites and years download in standardized formats with associated documentation and metadata including data product user guides and collection protocols. This standardized formatting allows you to easily work with the data using reproducible workflows. NEON also curates code resources to make it easier to work with the data.
NEON field sites also serve as an infrastructure to support additional research. Independent observers and Principle Investigators (PI) may work with Battelle staff on the NEON project to add additional instruments to existing NEON infrastructure and/or conduct additional sampling and/or experiments at NEON aquatic field sites.
Please note that the NEON project does not own the land for any of its field sites. Instead, Battelle, operator the NEON project, coordinates and partners with a variety of site hosts to build and operate sites. As a result, permissions for additional non-NEON research activities must be ultimately obtained from site hosts, a process that the NEON Project can assist researchers as needed.