FHAB API
History
In 2015, California’s State Water Resources Control Board (SWRCB) hosted a workshop by the National Oceanographic Atmospheric Administration (NOAA) to share information on a new technique to distinguish between cyanobacteria and algae blooms and estimate the concentration for each using satellite imagery.
Who created the tool?
With funding and guidance from the SWRCB, The San Francisco Estuary Institute/Aquatic Science Center (ASC) used processed imagery from NOAA and developed the Harmful Algal Bloom Analysis Tool, an interactive web application to display the data.
What does the tool do?
The user-friendly application displays a map that estimates the concentration of cyanobacteria within a selected waterbody and includes charts to track the long and short-term trends of the bloom. The user can also choose to display data for estimating the concentration of Chlorophyll-a, a broader estimate of primary productivity that includes but isn’t limited to cyanobacteria.
What is the purpose?
The main goal of the web application is to provide near-daily data for identifying the formation of harmful algal blooms in 255 large lakes and waterbodies across California. When a newly-formed bloom is identified by satellites, notifications are sent to staff at the SWRCB and regional water quality control boards to alert staff and help guide monitoring and event response as needed.
About the API data
This API may be used to directly access to the data displayed in the FHAB Satellite Web Map, which provides a screening level analysis to guide field verification and sampling to confirm the status of a suspected cyanobacteria harmful algal bloom and potential presence of toxic species.
Remotely-sensed data are processed daily into products for cyano index (Wynne et al. 2010) and estimated chlorophyll (Wynne et al. 2022). The resultant rasters are further composited into pixel-maximum composites (1-day and 10-day) to smooth out general noise and variability and better assess large-scale trends.
Zonal statistics are then derived for 255 waterbodies being tracked across California (including a few in bordering states) and stored in a database for quick retrieval and querying. These statistics feed the satellite web map and are provided through the API here, along with other routes for accessing related datasets as well as some novel analyses not provided in the web map.
Satellite data from 2002-2012 come from the MERIS instrument onboard the ENVISAT mission which has since ended operations. Satellite data from 2016 to present come from the OLCI instruments on board the Copernicus Sentinel-3 missions provided by EUMETSAT. Additional processing was provided by the NOAA National Ocean Service.
Data generated from the MERIS (ENVISAT satellite) data over 2002-2012 contains some known potential false positive readings, which result in occasional scattered pixel values that are above background levels but are not likely indicative of a real bloom. Please use data from 2002-2012 with care and interpret with discretion.
Disclaimer
In no event shall the creators, custodians, or distributors of this information be liable for any damages arising out of its use. These data are not legal documents or of survey quality and are not intended to be used as such. Although effort has been made to produce error-free and complete data, all geographic information has limitations due to the scale, resolution, date and interpretation of the original source materials. Data may be subject to change without prior notification. We request that the use of these data in any map, publication, or report should cite the data source(s) used and give proper attribution and credit to the originators of the data.
Contact
For any issues or questions, please contact [email protected].
Suggested reference
California Harmful Algal Bloom Satellite Analysis Application: Provided by California State Water Resources Control Board in partnership with the San Francisco Estuary Institute. California State Water Resources Control Board and San Francisco Estuary Institute, https://fhab.sfei.org. Accessed [date retrieved].
