“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.For more information, please contact: Malin Mohlin, Department of Marine Ecology, University of Gothenburg
Helena Aaberg | idw
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences