Writing in the Feb. 14 edition of the journal Environmental Research Letters, Stephen Carpenter of the University of Wisconsin-Madison and Elena Bennett of McGill University report that the human use of phosphorous, primarily in the industrialized world, is causing the widespread eutrophication of fresh surface water. What's more, the minable global stocks of phosphorous are concentrated in just a few countries and are in decline, posing the risk of global shortages within the next 20 years.
"There is a finite amount of phosphorous in the world," says Carpenter, a UW-Madison professor of limnology and one of the world's leading authorities on lakes and streams. "This is a material that's becoming more rare and we need to use it more efficiently."
Phosphorous is an essential element for life. Living organisms, including humans, have small amounts and the element is crucial for driving the energetic processes of cells. In agriculture, phosphorous mined from ancient marine deposits is widely used to boost crop yields. The element also has other industrial uses.
But excess phosphorous from fertilizer that washes from farm fields and suburban lawns into lakes and streams is the primary cause of the algae blooms that throw freshwater ecosystems out of kilter and degrade water quality. Phosphorous pollution poses a risk to fish and other aquatic life as well as to the animals and humans who depend on clean fresh water. In some instances, excess phosphorous sparks blooms of toxic algae, which pose a direct threat to human and animal life.
"If you have too much phosphorous, you get eutrophication," explains Carpenter of the cycle of excessive plant and algae growth that significantly degrades bodies of fresh water. "Phosphorous stimulates the growth of algae and weeds near shore and some of the algae can contain cyanobacteria, which are toxic. You lose fish. You lose water quality for drinking."
The fertilizer-fueled algae blooms themselves amplify the problem as the algae die and release accumulated phosphorous back into the water.
Carpenter and Bennett write in their Environmental Research Letters report that the "planetary boundary for freshwater eutrophication has been crossed while potential boundaries for ocean anoxic events and depletion of phosphate rock reserves loom in the future."
Complicating the problem, says Carpenter, is the fact that excess phosphorous in the environment is a problem primarily in the industrialized world, mainly Europe, North America and parts of Asia. In other parts of the world, notably Africa and Australia, soils are phosphorous poor, creating a stark imbalance. Ironically, soils in places like North America, where fertilizers with phosphorous are most commonly applied, are already loaded with the element.
"Some soils have plenty of phosphorous, and some soils do not and you need to add phosphorous to grow crops on them," Carpenter notes. "It's this patchiness that makes the problem tricky."
Bennett and Carpenter argue that agricultural practices to better conserve phosphate within agricultural ecosystems are necessary to avert the widespread pollution of surface waters. Phosphorous from parts of the world where the element is abundant, they say, can be moved to phosphorous deficient regions of the world by extracting phosphorous from manure, for example, using manure digesters.
Deposits of phosphate, the form of the element that is mined for agriculture and other purposes, take many millions of years to form. The nations with the largest reserves of the element are the United States, China and Morocco.
The new study was supported by grants from the U.S. National Science Foundation and the Natural Sciences and Engineering Research Council of Canada.
Terry Devitt, 608-262-8282, firstname.lastname@example.org
Steve Carpenter | EurekAlert!
Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen
Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
17.08.2018 | Physics and Astronomy
17.08.2018 | Information Technology
17.08.2018 | Life Sciences