Featured Research

from universities, journals, and other organizations

Native algae species to blame for 'rock snot' blooms in rivers worldwide

Date:
May 7, 2014
Source:
Dartmouth College
Summary:
The recent blooms of the freshwater algae known as 'rock snot' on river bottoms worldwide are caused by a native species responding to changing environmental conditions rather than by accidental introductions by fishermen or the emergence of a new genetic strain as widely believed, a study suggests. In fact, the algae have been native to much of the world for thousands of years, but conditions promoting visible growths were absent or rare.

The native freshwater algae known as "rock snot" grows on river bottoms worldwide.
Credit: Brad Taylor

The recent blooms of the freshwater algae known as "rock snot" on river bottoms worldwide are caused by a native species responding to changing environmental conditions rather than by accidental introductions by fishermen or the emergence of a new genetic strain as widely believed, a Dartmouth College-led study suggests.

Related Articles


In fact, the algae have been native to much of the world for thousands of years, but conditions promoting visible growths were absent or rare. The study, which includes researchers from Dartmouth and Environment Canada, appears in the journal BioScience.

Didymosphenia geminata, also known in the scientific vernacular as "didymo," is especially worrisome in salmon and trout rivers because it affects the insects they eat. The study suggests multimillion-dollar eradication efforts with chemicals and fishing restrictions are misguided, and that resources should be redirected at understanding and mitigating the environmental factors that trigger the blooms.

"Correctly identifying an invasive species as either native or nonnative is important for developing sound policy, management and scientific research programs because effective responses depend on knowing whether the species' dominance is caused by ecological or evolutionary novelty, changes in environmental conditions that facilitate it, or both," said Professor Brad Taylor, the study's lead author.

Didymo blooms were hastily attributed to human introductions or the emergence of new genetic strain because the absence of evidence was used as evidence of absence in many locations. "Even in locations where rock snot had been recorded a century ago, this information was either ignored or the idea of a new genetic strain was adopted," Taylor says.

Algal blooms are often caused by excessive phosphorus and other nutrient inputs, but didymo blooms occur because phosphorus is low. Rock snot lives on river bottoms and obtains nutrients from the water above. When nutrients are rare, the algae produce long stalks that extend the cell into the water above to access nutrients. The result of this stalk growth is thick mats covering the river bottom. "The paradox of didymo blooms in low-nutrient rivers is not really a paradox at all. However, the idea that low phosphorus can cause an algal bloom is hard for people to accept because we are all taught that more nutrients equal more algae," Taylor says. The study explains that other algae and bacteria respond similarly to low nutrients, but rock snot blooms are unprecedented, making this organism a good sentinel of what could be the new norm in many pristine rivers worldwide.

The new research suggests rock snot blooms have become more common because of climate change and other human-caused environmental changes that are decreasing phosphorus to levels that promote the formation of didymo blooms in many remote, otherwise pristine rivers worldwide.


Story Source:

The above story is based on materials provided by Dartmouth College. Note: Materials may be edited for content and length.


Journal Reference:

  1. B. W. Taylor, M. L. Bothwell. The Origin of Invasive Microorganisms Matters for Science, Policy, and Management: The Case of Didymosphenia geminata. BioScience, 2014; DOI: 10.1093/biosci/biu060

Cite This Page:

Dartmouth College. "Native algae species to blame for 'rock snot' blooms in rivers worldwide." ScienceDaily. ScienceDaily, 7 May 2014. <www.sciencedaily.com/releases/2014/05/140507132701.htm>.
Dartmouth College. (2014, May 7). Native algae species to blame for 'rock snot' blooms in rivers worldwide. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2014/05/140507132701.htm
Dartmouth College. "Native algae species to blame for 'rock snot' blooms in rivers worldwide." ScienceDaily. www.sciencedaily.com/releases/2014/05/140507132701.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins