Harmful Algae Event Database
The global reference for harmful algal events. Monitoring data from the IOC, ICES, and PICES regions since 1770.
Events Over Time
Reported EventsEvent Types
DistributionAbout HAEDAT
The Harmful Algal Event Database (HAEDAT) is a component of the Harmful Algal Information System (HAIS). It contains records of harmful algal events from the ICES area (North Atlantic) since 1985 and from the PICES area (North Pacific) since 2000.
IOC regional networks in South America, South Pacific, Asia, and North Africa are also contributing to this global effort.
Open User Manual →Disclaimer
A harmful algal event recorded in HAEDAT must be associated with demonstrable negative impacts on industry, biota, or society.
The database contains information based on yearly national reports by member states. The available information varies greatly between countries and years due to differences in monitoring intensity.
See the HAEDAT general information page for further background.
"Areas with numerous recorded occurrences may, in fact, experience fewer problems if they have efficient monitoring and management programmes."