Algal blooms aren’t always harmful, but when they are, science is here to help
USGS scientists across the nation are working to understand, predict and prevent impacts from harmful algal blooms to people and wildlife.
![Numerous brown blobs on a tan background marked with an uneven grid](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/thumbnails/image/K.brevis%20culture.png?itok=TK6bW9hm)
![A colony of cyanobacteria cells from Lake Okeechobee, Florida](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/thumbnails/image/microcystis_aeruginosa_calosahatchee_2016_bloom_6-1-16_site_1_cyano.jpg?itok=wdU0o09d)
![Notice sign on Marion Beach about an algae bloom potentially unsafe](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/thumbnails/image/marion06-29-06.png?itok=H980kdc8)
![Gloeotrichia, a type of cyanobacteria that can produce microcystin, in a water sample collected from Kabetogama Lake](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/media/images/Gloeotrichia%2C%20a%20type%20of%20cyanobacteria.png?itok=03bDP8e2)
Bloomin’ algae
Algae. If you’ve ever visited a pond, cleaned a fish tank, or eaten sushi, you’ve likely encountered some of these water-living, plant-like organisms. Algae come in many shapes and sizes and play important roles in ecosystems. For one, they make energy from sunlight through photosynthesis, which leads to them being the base of the food web in marine and freshwater communities. People even eat algae (see previous comment about sushi).
As a whole, algae also produce around 70 percent of the oxygen in the atmosphere!
These super stars are clearly important to our world as we know it and thrive in many conditions. Algae are really good at multiplying and when conditions are right, they can reach really high concentrations. When they do, it is called an algal bloom, and they are usually triggered by an increase in nutrients.
Algal blooms are responsible for some of the most magnificent phenomena on the planet. For example, when nutrient-rich water surges toward the surface near a coastline and causes an algal bloom, the bloom creates a food web feeding frenzy that often brings many, many species of animals together in a relatively small area.
However, unfortunately, an algal bloom can also become a runaway train. When an algal bloom “runs away" from ecological checks and balances, it can create negative consequences and if it does, it’s called a harmful algal bloom.
For instance, algal blooms can cause water bodies to become anoxic, meaning they have little-to-no oxygen. That’s a problem for fish and invertebrates, like shrimp, that rely on dissolved oxygen in the water.
Air-breathing animals, such as sea turtles, sea birds, or marine mammals, won’t suffocate in anoxic water conditions, but some algae produce toxins and these can harm animals, too. The addition of toxins makes the runaway algal blooms that much more hazardous to people and animals.
Beyond anoxic conditions and toxins produced by some algal blooms, there are less hazardous consequences as well. When a water body that supplies drinking water experiences an algal bloom, the algae can affect the water’s taste and odor. It can even clog water filtration systems. People might feel that algal blooms also decrease an area’s beauty.
Harmful algal blooms can lead to limited water availability and potentially result in toxicity for humans, pets, livestock and wildlife. And they are becoming more frequent.
Understanding more about harmful algal blooms is immensely important to people who manage water systems, both for societal and ecological purposes. What causes them? How can we detect them? How do they affect water quality and availability?
USGS studies harmful algal blooms
The USGS has a robust team of scientists studying harmful algal blooms. The scientists study the factors that cause algae to produce toxins, how and where wildlife and people are exposed to toxins, and how exposure to these toxins affects animals.
Additionally, USGS scientists are developing ways to forecast when and where harmful algal blooms may occur to inform efforts to protect the health of people, pets and wildlife.
Beyond toxins, USGS scientists who focus on water quality and availability are using some of the same tools to forecast and mitigate harmful algal blooms to protect drinking water and water management systems.
A USGS report published earlier this year covers the full capabilities of USGS in harmful algal bloom-related science and lays out a vision for the future of this research at the bureau.
A new plan for harmful algal bloom science opportunities
Despite the breadth of science that already exists on harmful algal blooms, there is much to learn. The new report takes aim at gaps in knowledge and provides key science opportunities to fill them.
Some of these science opportunities include:
- Expanding research into the effects of algal blooms in aquatic ecosystems, such as studying the effects of low levels of oxygen and toxins on aquatic life and food webs;
- Studying the toxicity of algal toxins, including how animals and people are exposed to toxins and the health effects of exposure for wildlife;
- Evaluating if there are socioeconomic impacts from algal blooms and associated toxins;
- Expanding research into what causes harmful algal blooms and associated toxins to form and how they persist, grow, move and disperse;
- Developing better modeling capabilities to enhance forecasting of harmful algal blooms, including toxin production;
- And improving harmful algal bloom detection and tracking, including with remote sensing.
Finally, although harmful algal blooms negatively impact something by definition, there are likely positive consequences of these blooms, too. One additional science opportunity addressed in the report includes research into the potential benefits of harmful algal blooms, which could include serving as a food source in an ecosystem or as fertilizer for agriculture, producing oxygen, sequestering carbon and being used as biofuels.
To read more about USGS’s capabilities in harmful algal bloom-related science and science opportunities, see the report, “Interdisciplinary Science Approach for harmful Algal Blooms (HABs) and Algal Toxins—A Strategic Science Vision for the U.S. Geological Survey.”
![Cyanobacterial bloom in Lake Okeechobee, FL (July 2016)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/thumbnails/image/Lake%20Okeechobee%20algal%20bloom%207_9_2016%20N%20Aumen%20cropped.jpg?itok=6JFCaMxW)
![Harmful Algae Bloom (HAB) - fish kill](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/thumbnails/image/hab_fish_kill.png?itok=wXxKEcrz)
![Cyanobacteria accumulation on shore of Williamson Reservoir](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/storytelling_grid/public/media/images/Picture1_17.png?itok=gs2Mbc0q)
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