HAB Incident Reports Map

Where are freshwater and estuarine HABs occurring in California?

This map only shows locations where harmful algal blooms (HABs) have been voluntarily reported. California currently does not have adequate funding for a statewide routine monitoring program so monitoring data is limited. A waterbody with no data is not an indication that a bloom is not present. Dots represent reported locations with pop-up windows providing additional data for each HAB incident such as field and/or lab results. Several routine monitoring programs exist for some locations (Klamath Basin, East Bay Regional Parks, Clear Lake, and reservoirs along State Water Project), which may share monitoring data to present in this map.

Note - The exact location, extent, and toxicity of the reported bloom may not be accurate and may not be affecting the entire waterbody. Please use data presented in this map for general purposes only, as it may contain errors. The data are subject to change as new information is received. Please check back for daily updates.