HABs explained: what, how and what now?

By Shahram Missaghi miss0035@umn.edu and Marte Kitson mkitson@d.umn.edu

Algae Terminology 101

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Algae blooms can turn the water green and smelly, and contribute to fish kills by creating dead zones in the water. Photo credit: Alaina Fedie, Science Museum of Minnesota

Algae are water-based photosynthesizing organisms that make their own food by using solar energy. Algae is not a type, group, domain, or kingdom of living things, but rather a collection of various organisms represented from different aquatic groups that can make their own food and are autotrophs. And so, algae come in many forms and shapes and are presented globally everywhere. They are one of the oldest known organisms. Algae are the primary producer (food) in aquatic systems and people have long been using them for food, medicine, and fuel as well.

Some algae begin their growth from the bottom sediments and spend their whole life cycle attached to sediment, others may become detached from the sediment and spend part of their life cycle floating in the water, while some only grow attached to other things, and yet many algae spend all or most of their life cycles suspended in the water as part of the plankton community, and are known as phytoplankton.
Under the right temperature and water conditions, some planktonic algae can grow very rapidly and form extremely high-density populations, or "blooms."

Algae blooms can turn the water green and smelly, and contribute to fish kills by creating dead zones in the water. At times, algae bloom also produce toxins that pose serious health risks to people and animals, and these algae are referred to as Harmful Algal Blooms or HABs. Blue-green algae or Cyanobacteria are one of the major types of HABs that are also found in Minnesota. With over 1500 freshwater species, cyanobacteria are well suited to live and grow in many aquatic systems. They generally tend to respond well to increased levels of a nutrient in the water and show a strong correlation between increased nutrient (total phosphorus) and their increased biomass. They also thrive in increased water temperature. Cynaobacteria can form HABs, become invasive, and produce toxins. More frequent HABs may be triggered by a number of factors including urban and agricultural runoff, as well as climate change.

What can you do to reduce HABs?

Fending off HABs starts upstream on the landscape with stormwater management as a critical part of HABs prevention to minimize excessive nutrients reaching our water bodies as well as understanding our aquatic systems to implement proper in-lake managements. University of Minnesota researchers have long been interested in HABs and minimizing their negative effects. Recently, using new lake-monitoring technology, Minnesota state agencies and scientists created a more complete picture of potential HABs in Minnesota. They also have come together to form a collaborative group to learn from each other, exchange ideas, provide training for water resources professionals, and provide public education.

The MN HAB group held a workshop (03/2016), funded by Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative‐Citizen Commission on Minnesota Resources (LCCMR), that was attended by more than 30 researchers and scientists from the University and state agencies. The group has also developed a web page (z.umn.edu/algae) to promote communication among all interested parties where you can also sign up to get e-news about blue-green algae in Minnesota lakes. So, get involved and sign up to join the group to understand HABs better and to protect and manage our state water resources.