Lakes suffering from harmful algal blooms may not respond to reduced, or even discontinued, artificial nitrogen loading. Many blue-green algae responsible for algal blooms can fix atmospheric nitrogen dissolved in the water, and therefore water stewards should focus their efforts on removing phosphorus from lakes to combat algal blooms.
This is according to a recently published article in Springer's Ecosystems journal, Biological Nitrogen Fixation Prevents the Response of a Eutrophic Lake to Reduced Loading of Nitrogen: Evidence from a 46-Year Whole-Lake Experiment. The paper presents the results of a 46-year whole-ecosystem experiment at IISD Experimental Lakes Area in northwestern Ontario, Canada.
Since 1969, researchers have been artificially manipulating a lake by adding varying amounts of carbon, nitrogen, and phosphorus to investigate the nutrients responsible for algal blooms. Throughout the experiment, researchers have been continually adding phosphorus.
However, forty years ago, researchers began reducing the amount of nitrogen they were adding to the lake, and from 1990-2013, they cut artificial nitrogen loading to zero. Despite these dramatic cuts in nitrogen loading algal blooms continued to cover the lake.
"We have been researching the role of artificial nitrogen in algal blooms for almost 50 years now, and these latest results clearly demonstrate that ceasing nitrogen loading into lakes has little effect on the size or duration of algal blooms," said Dr. Scott Higgins, Research Scientist at IISD Experimental Lakes Area and lead author on the paper.
"A number of algal species can make up for nitrogen deficits by fixing atmospheric nitrogen that is dissolved in the water. What is clear here is that phosphorus is the key driver of algal blooms in lake environments," added Higgins.
These results have clear implications for policy geared towards reducing algal blooms--especially for jurisdictions dealing with limited budgets.
"When governments are tackling algal blooms while working with limited resources, these results demonstrate that their efforts should be firmly focused on reducing phosphorus loading in lakes," said Dr. Michael Paterson, Senior Research Scientist at IISD Experimental Lakes Area, and secondary author on the paper.
Algal blooms are unsightly growths on water bodies that can produce toxins harmful to humans and animals, affect drinking water supplies, cause low oxygen 'dead zones' that result in fish kills, and a number of other negative consequences. Many freshwater lakes around the globe, including Lake Erie, Lake Winnipeg and Lake Taihu, have suffered from algal blooms for decades.
Research at IISD Experimental Lakes Area, the world's freshwater laboratory, identified phosphorus as the leading cause of algal blooms in lakes back in the 1970s, in a groundbreaking experiment on a whole lake ecosystem.
For more information, and to arrange an interview with the scientists, contact:
Media and Communications Officer,
IISD Experimental Lakes Area,
email@example.com or 1-204-958-7700 ext. 740
Sumeep Bath | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science 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