Authorizing Mandates | NOS Programs

This photo shows a classic “red tide” (although this one is brown in appearance) that occurs almost every summer along portions of Florida’s Gulf Coast. Photo: P. Schmidt, Charlotte (FL) Sun.

Harmful algal blooms (HABs) occur when algae, simple plants that live in the sea and form the base of the food web, produce toxic or harmful effects on people, fish, shellfish, marine mammals and birds. HABs have been reported in almost every U.S. coastal state, and their occurrence may be on the rise. The problem is of national concern, and is being studied by NOAA’s National Ocean Service, because HABs can adversely affect not only the health of people and marine organisms, but also the "health" of local and regional economies.

Algal species range from microscopic (such as phytoplankton) to the large, multicellular conglomerates commonly known as seaweeds. Generally, the proliferation of algae provides the energy source to fuel food webs, so most algae are not harmful even when they form “blooms” that are sometimes seen in rivers, estuaries and the ocean. A small percentage of algae, however, produce powerful toxins that can kill fish, shellfish, mammals and birds, and may directly or indirectly cause illness in people. HABs also include blooms of non-toxic species that have harmful effects on marine ecosystems. For example, when masses of algae die and decompose, they can deplete oxygen in the water, causing the water to become so low in oxygen that animals either leave the area or die.

These intricate line drawings of Pseudo-nitzschia are from a book published in 1943! At that time, scientist Easter Ellen Cupp observed specimens under the microscope, and then drew them freehand. From: Cupp, E.E. 1943. Marine Plankton Diatoms of the West Coast of North America. La Jolla: Scripps Institute of Oceanography, University of California Press.

The human illnesses caused by HABs, though rare, can be debilitating or even fatal. The person grows ill after consuming seafood that is tainted from the ingestion of biotoxin-producing algae. These syndromes include ciguatera fish poisoning and neurotoxic, diarrhetic, paralytic and amnesic shellfish poisoning.

One well-documented neurotoxin occurring in tainted shellfish is domoic acid, which can lead to amnesic shellfish poisoning in people. The causative organisms are diatoms in the genus Pseudo-nitzschia. They produce domoic acid which accumulates in the tissues of mussels, crabs, and fish. After consuming the tainted seafood, the affected person usually develops gastrointestinal distress, sometimes followed by confusion, memory loss, disorientation, and in extreme cases, coma and death. As in the case of all of these syndromes, there is no cure; medical personnel attempt to treat the symptoms until the patient improves.

The controlling factors for growth of many HAB species are not well understood. Studies indicate that many of these algal species flourish when specific wind and water current conditions produce and environment favorable to their growth. In addition, some HABs may be linked to over-enrichment of nutrients when runoff from lawns, roads, and farmland accumulate at a rate that "overfeeds" the algae that exist normally in the environment. Some HABs have also been reported in the aftermath of natural phenomena including sluggish water circulation, unusually high water temperatures, and extreme weather events such as hurricanes, floods, and drought.

An electron microscope view of Karenia brevis, the alga that causes red tide.

Perhaps the best known HAB is the so-called “red tide” that occurs nearly every summer along Florida’s Gulf Coast, and that Spanish explorers first observed in the 16th century! The organism that causes the Florida red tide (which may not always appear red), a microscopic alga called Karenia brevis, produces a toxin that makes shellfish dangerous to eat. It also kills fish, and in some instances, dolphins and manatees. It may also make the surrounding air difficult to breathe due to aerosolized toxins. Scientists have been monitoring and studying the phenomenon for a number of years to determine how to detect and forecast the location of the blooms. The goal is to give communities advance warnings so they can adequately plan and deal with the adverse environmental and health affects associated with these red-tide events.

HABs are costly not only in health terms but in economic ones as well. At present, they cause about $82 million in economic losses to the seafood, restaurant and tourism industries each year. HABs reduce tourism, close beaches and shellfish beds, and decrease the catch from both recreational and commercial fisheries.

When an algal bloom severely depletes the oxygen in coastal waters, massive die-offs of fish species (known as “fish kills”) can occur.

Authorizing Mandates

The Harmful Algal Bloom and Hypoxia Research and Control Act was signed into law on November 13, 1998, becoming P.L. 105-383 and reauthorized in December 2004 (P.L. 108-456). The Act recognized that many U.S. coastal areas suffer from HABs and hypoxia each year, threatening coastal ecosystems and endangering human health. To respond to these concerns, the Act calls for:(1) the establishment of an interagency task force on HABs and hypoxia (low dissolved oxygen); (2) a national assessment on HABs in coastal waters; (3) a national assessment on freshwater HABs; (4) a national assessment on hypoxia; (5) a report on prediction and response for HABs; and (6) a national scientific research, development, demonstration, and technology transfer plan for reducing impacts of HABs.   

The Oceans and Human Health Act was also passed, establishing intramural Centers of Excellence and providing funding for intramural and extramural research on HABs and other health problems in an ecosystems context.

The Coastal Zone Management Act also authorizes HAB monitoring.

NOS Programs

As the federal agency largely responsible for overseeing the nation’s marine resources, NOAA is carefully studying what causes HABs and how they can be predicted and prevented. Within NOAA’s National Ocean Service (NOS), much of this work is conducted through its National Centers for Coastal Ocean Science (NCCOS), which maintains the Harmful Algal Bloom Web Site. This Web site provides information on HABs, including information on HAB ecology and forecasting and workshops and meetings, as well as news releases and related links.

A major goal is to provide early-warning systems for coastal communities when they are likely to experience the detrimental effects of a HAB event. In the effort to achieve this goal, NCCOS is developing a variety of sensing technologies and conducting research to determine environmental factors that trigger HABs.

This satellite image reveals high concentrations of chlorophyll over a large area (in red), warning scientists of potential HAB activity off the Florida Gulf Coast. Water samples will provide data on the algal species proliferating there.

The NCCOS Center for Coastal Monitoring and Assessment provides information on HAB identification and monitoring. It uses models, together with data from satellite sensors and field and instrument observations from research vessels, to develop the remote sensing methods necessary to monitor and forecast HABs. A collaboration between NCCOS and the NOAA Coastal Services Center produced a first-generation remote sensing tool to identify and predict the movement of HABs in the Gulf of Mexico. Bulletins containing this information are developed by integrating data from various ocean-observing systems, including imagery from commercial and government satellites supported by the NOAA CoastWatch Program; meteorological data from NOAA observing stations; and field data collected by state and university monitoring programs. The information is now being produced operationally by NOAA's Center for Operational Oceanographic Products and Services. These bulletins enable coastal resource managers to respond rapidly to conditions that may negatively impact coastal habitats and marine life in their areas.

Additionally, NCCOS is currently working with the state of Florida to monitor and predict Gulf Coast red tides. This work will continue in the Pacific Northwest region to track toxic blooms caused by certain species of Pseudo-nitzschia.

Through its MERHAB (Monitoring and Event Response for Harmful Algal Blooms) Program, the NCCOS Center for Sponsored Coastal Ocean Research (CSCOR) conducts intensive, short time-scale monitoring of physical, chemical, and biological properties in areas where HABs are known to occur. Initial MERHAB regional efforts focused on HAB monitoring in the Chesapeake Bay, a Florida estuary, and along Washington’s Olympic Peninsula. The program is being expanded to additional coastal communities.

This Karenia brevis bloom off the coast of the Florida panhandle was monitored as part of a long-term regional study sponsored by ECOHAB. These blooms may last from weeks to months.

Another CSCOR program is ECOHAB (Ecology and Oceanography of Harmful Algal Blooms), a multi-agency partnership between CSCOR and the National Science Foundation, U.S. Environmental Protection Agency, NASA and the Office of Naval Research. Through long-term regional studies and short-term targeted studies, ECOHAB seeks to produce new detection methods for HABs and their toxins, to understand the causes and dynamics of HABs, to develop forecasts of HAB formation, growth, transport, and toxicity, and to predict and reduce impacts on people and ecosystems.

Scientists at the NCCOS Center for Coastal Environmental Health and Biomolecular Research (CCEHBR) have developed new in-the-field blood-sampling technology that can identify the presence of toxins in living animals. The development is significant because it may improve resource managers’ ability to predict the impact of a HAB during its initial stages.

The Marine Biotoxins Program at CCEHBR established the HAB analytical response team (ART). The ART provides scientific guidance and identification of harmful algae and their toxins during suspected HABs, during marine animal mortality events, and during human poisonings.

NCCOS’s HAB Ecology and Physiology Program at the Center for Coastal Fisheries and Habitat Research offers scientific guidance and information to resource managers and the coastal community on concerns involving the effects of toxic or harmful algae. The program’s goal is to promote safe, effective management of coastal ecosystems and resources.