California Harmful Algal Blooms (HABs) Portal

The CA HABs Portal is the central resource for HABs in the state of California. HABs can pose a health risk to people and animals, harm aquatic ecosystems, and limit the use of drinking and recreational waterbodies due to the toxins, odors, and scums or mats they can produce.

The Portal is an informational resource for the public and also functions as a tool to support coordination with statewide partners to address HABs. The content is developed by the California Cyanobacteria and HAB (CCHAB) Network and participating state agencies.

Although, the content in this Portal focuses on freshwater and estuarine HABs, marine (coastal) HAB information is displayed when reported to the CA Water Boards agency.

For information on marine (coastal) HABs, including red tides, please refer to the California Harmful Algal Bloom Monitoring and Alert Program (CalHABMAP) and CDPH's Marine Biotoxin Monitoring Program webpages.

Healthy Water Habits Video

Understanding the Dangers of Blue-green Algae (Cyanobacteria)

Credit: Department of Water Resources

HAB Incident Reports Map

HAB Incident Reports Map provides data on voluntarily reported blooms in California.

The data may include reports under investigation and/or confirmed incidents of HABs.

Satellite HAB Map

This mapping tool displays satellite imagery that estimates cyanobacteria HABs and chlorophyll in large waterbodies and associated parameters.