Harmful Algal Blooms
Algal blooms, or "red tides," are caused by aggregations of tiny marine plants, some of which contain reddish pigment. Algae are normal components of all aquatic environments, but can produce what is known as a “harmful algal bloom” or “HAB” when they bloom in significant numbers, lead to oxygen depletion, or generate toxic byproducts. HABs can harm marine organisms and some also impact human health.
Select from the choices below to learn more about HABs and HAB research at the Virginia Institute of Marine Science.

What are HABs?
Algae are normal parts of aquatic environments, but can form “harmful algal blooms” when good algae go bad.

HAB Species
Learn about local species that can form harmful algal blooms when they proliferate or generate toxic byproducts.

Impacts
Discover the many ways that harmful algal blooms impact marine life and human health in Chesapeake Bay and worldwide.

Report a HAB
Notify us if you've encountered an algal bloom or fish kill in Chesapeake Bay or nearby coastal waters.

Research
Cutting-edge science at VIMS helps to better understand and manage harmful algal blooms and their impacts.

HAB Tech
From molecular assays to drones and cytobots, VIMS is at the cutting-edge of using tech to better understand and manage HABs.

Videos
Enter the microscopic world of Chesapeake Bay algae that are capable of producing harmful algal blooms.