NOAA logo National Ocean Service

Harmful Algal Blooms

26 August 2011, 2:50 pm

Harmful Algal Blooms

Harmful Algal Blooms: Simple Plants With Toxic Implications

Ranging from microscopic, single-celled organisms to large seaweeds, algae are simple plants that form the base of food webs. Sometimes, however, their roles are much more sinister. A small percentage of algal species produce toxins that can kill fish, mammals, and birds, and may cause human illness. Other algae are nontoxic, but clog the gills of fish and invertebrates or smother corals and submerged aquatic vegetation.  Others discolor water, form huge, smelly piles on beaches, or cause drinking water and fish to taste bad.

  • HAB Impacts Are Far Reaching.
  • Harmful algal bloom (HAB) events can be very bad for us. People who eat shellfish from waters experiencing toxic blooms can become very ill and can even die. Does that mean that the seafood you eat may be unsafe? Not at all. Rigorous state shellfish monitoring programs insure that legally harvested seafood is safe for human consumption. HABs also have economic and cultural implications, especially in coastal communities dependent on harvesting seafood and tourism. They frequently disrupt the commercial, recreational and subsistence seafood harvesting and cause some to cancel beach vacations.

    As a result HABs cost coastal communities a substantial amount. Coastal HAB events have been estimated to result in economic impacts in the United States of at least $82 million each year. These impacts stress the importance of understanding HABs and developing tools to mitigate their impacts and ultimately to control or even prevent them.

  • A Legislative Mandate.

    In December 2004, the Harmful Algal Bloom and Hypoxia Amendments Act of 2004 (Public Law 108-456) was signed into law.

    This Act, originally passed in 1998, reaffirms and expands the mandate for NOAA to advance scientific understanding and detection, monitoring, assessment, and prediction of harmful algal blooms (HABs) and hypoxia (low oxygen).

    The Act calls for development of programs to research methods of prevention, control, and mitigation of HABs and establishes an interagency task force to follow progress on these issues.

    Tools and technologies being developed under the Act are helping coastal managers lessen or prevent impacts on human health and coastal resources.

  • Understanding HABs Where They Occur.

    Although all coastal states experience harmful algal blooms, different organisms live in different places and cause different problems. Other factors, such as the structure of the coast, runoff, oceanography, and other organisms in the water, can also change the scope and severity of HAB impacts.

    To address these differences, NOS takes a regional approach in developing strategies for HAB management.  By developing specific tools and information for areas of the country, including the Gulf of Mexico, Great Lakes, Northeast, Pacific Coast, Mid-Atlantic/Southeast, and Caribbean/Pacific Islands, NOS is able to advance management capabilities in dealing with all major HAB threats.

  • HABs and Climate Change.

    Climate is always changing. Because the growth, toxicity, and distribution of harmful algal bloom (HAB) species are all tied to the environment, changes in climate can change the occurrence, severity, and impacts of HAB events.

    Climate change will largely manifest as regional changes, which closely aligns with NOS’s regional approach to its HAB research. This knowledge will be critical to developing strategies for management of HABs in already vulnerable coastal and marine areas into the future.

    To understand how future climate changes may impact HABs, NOAA supports a wide variety of research. The Center for Sponsored Coastal Ocean Research, for example, supports projects addressing the impacts of climate change on HABs in estuarine, coastal, and Great Lakes ecosystems.

    NOAA's Oceans and Human Health Initiative (OHHI) also supports HAB research related to climate change. At OHHI's West Coast Center, researchers are studying human health impacts related to environmental variability and climate change — factors that impact the severity, transport, concentration, and dispersion of HABs.

  • Research to Combat HABs.

    The National Centers for Coastal Ocean Science (NCCOS) is leading NOAA efforts to research and understand harmful algal blooms (HABs), to develop tools to combat these toxic tides.

    For example, NCCOS’s Ecology and Oceanography of Harmful Algal Blooms Research Program is producing new methods to detect HABs and their toxins, to understand HAB dynamics, to develop HAB forecasts, and to predict and reduce impacts on people and ecosystems.

    The NOAA Monitoring and Event Response for Harmful Algal Blooms Research Program  is expanding efforts to monitor waters and shellfish, to help more coastal communities know when they are at risk and how to respond.

    While most HAB programs in NOAA fall within NCCOS, HAB research, management, and response efforts span across many offices. NOAA's Oceans & Human Health Initiative, for example, supports a wide range of HAB research with a focus on public health.

Original article: Harmful Algal Blooms