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HAB Monitoring in California

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Why are they important?

Some harmful algae produce potent toxins which cause illness or death in humans and marine organisms—fish, seabirds, manatees, sea lions, turtles, and dolphins are some commonly affected animals. Other types of harmful algae are nontoxic to humans but cause harm to fish and invertebrates by damaging or clogging their gills or by forming such large blooms that the death and subsequent decay of the algae lead to hypoxia (oxygen depletion) in the bottom waters of marine environments. Dense blooms can also block sunlight for beneficial algae and seagrasses. 

HABs can have major negative impacts on local economies, and a recent conservative assessment estimates that HABs occurring in marine waters alone have an average annual impact of $82 million dollars in the U.S.

All U.S. coastal states have experienced HABs over the last decade, and new species have emerged in some locations that were not previously known to have problems.  HABs occur naturally, but human activities that disturb ecosystems in the form of increased nutrient loadings and pollution, food web alterations, introduced species, and water flow modifications have been linked to the increased occurrence of some HABs.

Text from Center for Sponsored Coastal Ocean Research

For More Information

NOAA National Ocean Service

Economic Impact

Center for Sponsored Coastal Ocean Research

Human Health

Centers for Disease Control and Prevention