Navigation Links
Increasing toxicity of algal blooms tied to nutrient enrichment and climate change
Date:10/24/2013

CORVALLIS, Ore. Nutrient enrichment and climate change are posing yet another concern of growing importance: an apparent increase in the toxicity of some algal blooms in freshwater lakes and estuaries around the world, which threatens aquatic organisms, ecosystem health and human drinking water safety.

As this nutrient enrichment, or "eutrophication" increases, so will the proportion of toxin-producing strains of cyanobacteria in harmful algal blooms, scientists said.

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 believed to have produced the oxygen that paved the way for terrestrial life to evolve. They are highly adaptive and persistent, researchers say, and today are once again adapting to new conditions in a way that threatens some of the life they originally made possible.

A particular concern is Microcystis sp., a near-ubiquitous cyanobacterium that thrives in warm, nutrient-rich and stagnant waters around the world. Like many cyanobacteria, it can regulate its position 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 basically the cockroaches of the aquatic world, they're the uninvited guest that just won't leave," said Timothy Otten, a postdoctoral scholar in the OSU College of Science and College of Agricultural Sciences. His work has been supported by the National Science Foundation.

"When one considers their evolutionary history and the fact 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 minimize the conditions that favor their proliferation."

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 are plagued each year by algal blooms so massive that they are visible from outer space.

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 have been retained over millions of years.

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

Also, since cyanobacteria blooms become entrenched and usually occur every summer in impacted systems, chronic exposure to drinking water containing these compounds is an important concern that needs more attention, Otten said.

"Water quality managers have a toolbox of options to mitigate cyanobacteria toxicity issues, assuming they are aware of the problem and compelled to act," Otten said. "But there are no formal regulations in place on how to respond to bloom events.

"We need to increase public awareness of these issues," he said. "With a warming climate, rising carbon dioxide levels, dams on more rivers than not, and overloading of nutrients into our waterways, the magnitude and duration of toxic cyanobacterial blooms is only going to get worse."


'/>"/>

Contact: Tim Otten
ottent@onid.orst.edu
541-737-1796
Oregon State University
Source:Eurekalert  

Related biology news :

1. New study finds nighttime heat waves increasing in Pacific Northwest
2. Research shows Vitamin D levels drop after pediatric heart surgery, increasing sickness
3. AACR news: Studies show increasing evidence that androgen drives breast cancer
4. New hypothesis: Why bacteria are becoming increasingly more resistant to antibiotics
5. Increasing evidence links high glycemic index foods and dairy products to acne
6. Antibacterial agent used in common soaps found in increasing amounts in freshwater lakes
7. Ornamental fish industry faces increasing problems with antibiotic resistance
8. Community-based nutrition education shown to be successful in increasing calcium intake
9. Fire and ice: Wildfires darkening Greenland snowpack, increasing melting
10. Increasing drought stress challenges vulnerable hydraulic system of plants, GW professor finds
11. Environmental concerns increasing infectious disease in amphibians, other animals
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Increasing toxicity of algal blooms tied to nutrient enrichment and climate change
(Date:6/20/2016)... DALLAS , June 20, 2016 ... criminal justice technology solutions for public safety, investigation, ... by the prisons involved, it has secured the ... Corrections (DOC) facilities for Managed Access Systems (MAS) ... (4) additional facilities to be installed by October, ...
(Date:6/9/2016)... , June 9, 2016 ... deploy Teleste,s video security solution to ensure the safety of ... during the major tournament Teleste, an ... systems and services, announced today that its video security solution ... to back up public safety across the country. The ...
(Date:6/2/2016)... NEW YORK , June 2, 2016   The ... (Weather), is announcing Watson Ads, an industry-first capability in which ... advertising, by being able to ask questions via voice or ... Marketers have long ... with the consumer, that can be personal, relevant and valuable; ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 27, 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: BRM) ("Biorem" or ... its major shareholders, Clean Technology Fund I, LP and ... based venture capital funds which together hold ... a fully diluted, as converted basis), that they have ... entire equity holdings in Biorem to TUS Holdings Co. ...
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf K. Hoffmann, ... faculty of the University of North Carolina Kenan-Flagler Business School effective ... at UNC Kenan-Flagler, with a focus on the school’s international efforts, leading classes ...
(Date:6/24/2016)... ... ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension of ... higher end machines that use the more unconventional z-dimension of 20mm. Z-dimension ... of the cuvette holder. , FireflySci has developed several Agilent flow cell product ...
(Date:6/23/2016)... 23, 2016 /PRNewswire/ - FACIT has announced the ... biotechnology company, Propellon Therapeutics Inc. ("Propellon" or ... of a portfolio of first-in-class WDR5 inhibitors for ... as WDR5 represent an exciting class of therapies, ... medicine for cancer patients. Substantial advances have been ...
Breaking Biology Technology: