# Increasing toxicity of algal blooms tied to nutrient enrichment and climate change

- Link: https://greenlivingguy.com/2019/03/increasing-toxicity-of-algal-blooms-tied-to-nutrient-enrichment-and-climate-change/
- Published: 2019-03-03T16:46:41-05:00
- Author: greenlivingguy

### By David Stauth

CORVALLIS, Ore. – Nutrient enrichment and climate change are posing yet another 
concern of growing importance. Cause there’s an apparent increase in toxicity in
water. That’s some algal blooms. Especially in freshwater lakes and estuaries around
the world. All of which threaten aquatic organisms. In addition, ecosystem health
and human drinking water safety.

![](https://i0.wp.com/greenlivingguy.com/wp-content/uploads/2019/03/liz-harrell-
yvn5UBRamAM-unsplash.jpg?resize=420%2C280&quality=52&ssl=1)

## So yes. This nutrient enrichment, or “eutrophication,” increases.

All creating toxin-producing strains of cyanobacteria in harmful algal blooms. That’s
what scientists saying.

Researchers from Oregon State University and the University of North Carolina at
Chapel Hill will outline recent findings in an analysis Friday in the journal Science.

Cyanobacteria are some of the oldest microorganisms on Earth, dating back about 
3.5 billion years to a time when the planet was void of oxygen and barren of most
life. These bacteria are to have produced the oxygen that paved the way for terrestrial
life to evolve. They are highly adaptive and persistent. Furthermore, researchers
say, today are again adapting to new conditions. That’s in a way that threatens 
some of the life they originally made possible.

### A particular concern is Microcystis sp., a near-ubiquitous cyanobactecrium that thrives in warm, nutrient-rich and stagnant waters around the world. Like many cyanobacteria, it can regulate its place in the water column, and often forms green, paint-like scums near the surface.

In a high-light, oxidizing environment, microcystin-producing cyanobacteria have
a survival advantage over other forms of cyanobacteria that are not toxic. Over 
time, they can displace the nontoxic strains, resulting in blooms that are increasingly
toxic.

“Cyanobacteria are the cockroaches of the aquatic world,” said Timothy Otten, a 
postdoctoral scholar in the OSU College of Science and College of Agricultural Sciences,
whose work supported by the National Science Foundation. “They’re the uninvited 
guest that just won’t leave.”

### “When one considers their evolutionary history and that they’ve persisted even through ice ages and asteroid strikes, it’s not surprising they’re extremely difficult to remove once they’ve taken hold in a lake,” he said. “For the most part, the best we can do is to try to decrease the conditions that favor their increase.”

Researchers lack an extensive historical record of bloom events and their associated
toxicities to put current observations into a long-term context.  However, Otten
said, “If you go looking for toxin-producing cyanobacteria, chances are you won’t
have to look very long until you find some.”

There are more than 123,000 lakes greater than 10 acres in size spread across the
United States, and based on the last EPA National Lakes Assessment, at least one-
third may contain toxin-producing cyanobacteria. Dams; rising temperatures and carbon
dioxide concentrations; droughts; and increased runoff of nutrients from urban and
agricultural lands are all compounding the problem.

Many large, eutrophic lakes such as Lake Erie plagued each year by algal blooms 
so massive that they are visible from outer space. Dogs have died from drinking 
contaminated water.

“Researchers studying cyanobacterial toxins say it’s improbable that their true 
function was to be toxic, since they actually predate any predators. New research
suggests that the potent liver toxin and possible carcinogen, microcystin, has a
protective role in cyanobacteria and helps them respond to oxidative stress. This
is probably one of the reasons the genes involved in its biosynthesis are so widespread
across cyanobacteria and retained over millions of years.”

Because of their buoyancy and the location of toxins primarily within the cell. 
Cause exposure risks are greatest near the water’s surface. Therefore all which 
raises concerns for swimming, boating and other recreational uses.

### “We need to increase public awareness of these issues,” he said. As is clear and with a warming climate. With all comes rising carbon dioxide levels. So dams on many rivers are overloading of nutrients. Finally, then they flow into our waterways. Therefore the size and duration of toxic cyanobacterial blooms oy! Things are only getting worse.

Source: Oregon State University

### 󠀁[⌊Especially in freshwater lakes and estuaries around the world. All which threatens aquatic organisms. In addition, ecosystem health and human drinking water safety. So yes. This nutrient enrichment, or “eutrophication” increases. All creating toxin-producing strains of cyanobacteria in harmful algal blooms. That’s what scientists saying.⌉⌊Especially in freshwater lakes and estuaries around the world. All which threatens aquatic organisms. In addition, ecosystem health and human drinking water safety. So yes. This nutrient enrichment, or “eutrophication” increases. All creating toxin-producing strains of cyanobacteria in harmful algal blooms. That’s what scientists saying.⌉󠀁[