Wednesday, August 27, 2008

Harmful algal blooms, or HABs

Harmful algal blooms, or HABs, in the new limno-lingo, represent a serious issue. When I was in lake school many years ago, we knew that certain algae could be hazardous. But these were marine algae that caused red tides or were rare events in freshwater, and then usually in cow ponds. Now HABs are front and center at many lakes.

The EPA report, Scientific Assessment of Freshwater Harmful Algal Blooms (available from EPA as a PDF) is the latest compendium of HAB science and is the techno-tell-all of what we know and what we no not know about HABs. We know for example that:
“Freshwater HAB toxins can have a broad range of negative impacts on humans, animals, and aquatic ecosystems. Many cyanobacteria can produce neurotoxic, hepatotoxic, dermatotoxic, or other bioactive compounds, and blooms of toxigenic cyanobacteria pose a particular threat if they occur in drinking water sources.”
A lot of new words and jargon that say in essence that these blooms can’t be good.

Seriously, as lake managers, we cannot ignore HABs. HABs pose threats beyond what we have traditionally dealt with as lake managers. HABs threaten water supplies, human health, and fish and wildlife.

What we don’t know or at least don’t know well includes risk assessment, analytical methods, toxicity pathways, or the appropriate response framework. The report provides an assessment and roadmap to better attend to these needs.

Of course, if we confront lakes experiencing HABs, we cannot wait for the answers to all the unknowns. We can fall back on our tried-and-true approaches to lake management - lake management basics – which ought to be relied upon to minimize and manage the impacts of HABs.

This means priority ought to be given to nutrient management. Specifically,
  • Top priority for watershed protection for those lakes not yet affected by HABs
  • For lakes already experiencing HABs, watershed rehabilitation may be too slow, so in addition, we should initiate in-lake nutrient reduction methods.
  • In cases where nutrient reduction may not be timely or sufficient, other in-lake techniques should be used.
These strategies and techniques are explained fully in the textbook, Restoration and Management of Lakes and Reservoirs or the manual, Managing Lakes and Reservoirs – both available in the NALMS Bookstore (currently off-line). You may also purchase Managing Lakes and Reservoirs through using the Lake Stewardship Store.

Article by Dick Osgood, President of the North American Lake Management Society (NALMS), used by permission. Read the latest NALMS' newsletter online.


  1. algae gives oil , pollutes water.It looks like algae has both hero and antihero property

  2. The Technological Development Unit (UDT, Unidad de Desarrollo Tecnológico) of the University of Concepcion, Chile, and the Chilean Technical Association of Pulp and Paper (ATCP-Chile) have the pleasure to announce the “Second Latin American Congress on Biorefineries: Materials and Energy” to be held on May 4th, 5th and 6th, 2009 in Termas de Chillan, Chile.

    The 20th century was ruled by oil, which is the source not only of transportation fuels but also of many products that are omnipresent in every field of human endeavor. In view of the inevitable increases in the price of oil because of its gradual and inexorable depletion, current oil refineries will increasingly give way to the “biorefineries” of the future, which – based on renewable agricultural and forest products - will continue to produce the energy and the materials that society will require in the 21st century and beyond.

    The Congress offers a forum to national and foreign researchers and experts for a productive debate on scientific and engineering advances in the use of forest biomass as a source of fuels, new materials and chemical products, as well as a stimulating discussion on the challenges and opportunities for regional, national and Latin American cooperation in these endeavors.

    Topics included within the scope of this Congress:

    1. Chemical transformation: Fermentation of sugars; anaerobic digestión of biomass residues to obtain bioethanol or biogas; pretreatments; development of processes; purification and conditioning of products.

    2. Thermochemical transformation: Solid, liquid and gaseous products of thermochemical degradation of lignocellulosic feedstocks; pyrolysis and gasification for fuels and chemical products of commercial interest.

    3. Physical transformation: Separation of forest biomass components through new technologies and transformation into products of commercial interest; preparation, conditioning and densification of biomass to facilitate transport, storage, processing and/or homogeneity of composition.

    The Congress will be held in Termas de Chillan, a prime tourist attraction located in the Bio Bio region just 194 kilometers (120.5 miles) east of the city of Concepcion.

    For more information please visit our website or, or send an e-mail to

    If possible, please publish this information on their websites.

    Unidad de Desarrollo Tecnológico
    Universidad de Concepción
    Fono: (56-041)2747438