Featured Research

from universities, journals, and other organizations

Eutrophication makes toxic cyanobacteria more toxic

Date:
December 9, 2010
Source:
University of Gothenburg
Summary:
Continued eutrophication of the Baltic Sea, combined with an ever thinner ozone layer, is favouing the toxic cyanobacterium Nodularia spumigena, reveals new research.

This is a satellite image of a Nodularia bloom.
Credit: SMHI; EOS 8211; MODIS 2005-07-11, NASA, processed by SMHI8217 oceanography unit.

Continued eutrophication of the Baltic Sea, combined with an ever thinner ozone layer, is favouring the toxic cyanobacterium Nodularia spumigena, reveals research from the University of Gothenburg, Sweden.

"There are several species of cyanobacteria, or blue-green algae, that can form surface blooms in the Baltic Sea," explains Malin Mohlin from the University of Gothenburg's Department of Marine Ecology. "Which species ends up dominating a bloom depends partly on how they deal with an increased amount of UV light and a shortage of nutrients. Nodularia spumigena is most toxic when there is little nitrogen in the water but sufficient amounts of phosphorus."

As a result, wastewater treatment processes that concentrate on removing nitrogen can make cyanobacterial blooms more toxic. Wastewater therefore needs to be cleared of both nitrogen and phosphorus.

Mohlin's research shows that Nodularia spumigena can be expected to be most toxic at the beginning of a bloom in July. At that time there is generally more phosphorus than nitrogen in the water, and the cyanobacteria have not yet to float to the surface but are found deeper in the water where they have not yet been exposed to UV light.

Surface blooms of cyanobacteria, which are a type of phytoplankton, have increased in both frequency and magnitude in the Baltic Sea in recent decades, and researchers are divided on the cause. Some put it down to eutrophication -- an excess of nutrients in the water -- caused by human emissions of nitrogen and phosphorus over the past 150 years. Others have studied the Baltic Sea's bottom sediment and argue that this is a natural phenomenon that has been ongoing for more than 7,000 years and is due instead to climate variations.

Different species of nitrogen-fixing cyanobacteria bloom at different times. Aphanizomenon species tend to bloom from May to June, but from July to August the toxic species Nodularia spumigena normally dominates for as long as the surface water is warm and still.

The toxin it produces is called nodularin and is a hepatotoxin -- a toxin that attacks the liver. Livestock and dogs around the Baltic Sea have died after consuming large quantities of toxic water during blooms.

The thesis has been successfully defended.


Story Source:

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


Cite This Page:

University of Gothenburg. "Eutrophication makes toxic cyanobacteria more toxic." ScienceDaily. ScienceDaily, 9 December 2010. <www.sciencedaily.com/releases/2010/12/101206111442.htm>.
University of Gothenburg. (2010, December 9). Eutrophication makes toxic cyanobacteria more toxic. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2010/12/101206111442.htm
University of Gothenburg. "Eutrophication makes toxic cyanobacteria more toxic." ScienceDaily. www.sciencedaily.com/releases/2010/12/101206111442.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
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:
from the past week

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