A harmful algal bloom (HAB), or excessive algae growth, sometimes called a red tide in marine environments, is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, water deoxygenation, mechanical damage to other organisms, or by other means.

Jan 9, 2024 · Harmful algal blooms are the rapid growth of algae or cyanobacteria in water that can harm people, animals, or the environment. Going in or near water with a harmful algal bloom can make you and your animals sick. Stay out if water looks discolored, has scum, or smells bad.

Mar 26, 2025 · Toxic algae blooms contain a neurotoxin that is likely impacting the sea lions. Sea lions on the California coast are reportedly displaying strange behavior, likely due to a harmful algae bloom ...

Feb 24, 2025 · Harmful blooms of cyanobacteria are most commonly found in fresh water such as lakes, rivers, and streams. Signs and symptoms caused by these harmful algal blooms vary based on toxin and exposure. Illnesses can be mild to life-threatening. People may ingest cyanobacteria or their toxins by:

Mar 6, 2025 · Harmful algal blooms (HABs) occur when algae or cyanobacteria produce toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. HABs can have adverse effects on human, animal, and ecosystem health, and cause significant economic impacts to coastal communities.

Feb 5, 2025 · The most common algae associated with marine toxic HABs include the dinoflagellates (e.g., Florida red tide Karenia brevis) and diatoms (Pseudo-nitzschia) while those most associated with freshwaters are dominated by cyanobacteria (e.g., Microcystis).

Jun 4, 2024 · A harmful algal bloom (HAB) occurs when toxin-producing algae grow excessively in a body of water. The excessive algal growth, or algal bloom, becomes visible to the naked eye and can be green, blue-green, red, or brown, depending on the type of algae.

Apr 27, 2016 · Harmful algal blooms, or HABs, occur when colonies of algae — simple plants that live in the sea and freshwater — grow out of control and produce toxic or harmful effects on people, fish, shellfish, marine mammals, and birds.

Apr 2, 2024 · Harmful algal blooms are caused by certain types of algae and cyanobacteria (also called blue-green algae). Harmful algal blooms, and the toxins they make, can cause mild to life-threatening symptoms in people and animals.

Jun 16, 2024 · Harmful algal blooms (HABs) occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds.