Stories tagged phosphorus

May
02
2011

the ocean's 5 major gyres
the ocean's 5 major gyresCourtesy NOAA
We often talk about the ocean ecosystem. And, indeed, there is really just one, world-wide ocean, since all oceans are connected. An Indian Ocean earthquake sends tsunami waves to distant coasts. Whitecaps look as white anywhere in the world. The ocean swirls in similar patterns.

However, oceanographers do find differences from place to place. For example, let’s take a closer look at the chemistry of two swirls, or gyres as they’re more properly called. Scientists have found a micro difference between the North Atlantic Gyre and the North Pacific Gyre. The Atlantic generally has really low levels of phosphorus, measurably lower than the North Pacific Gyre.

the element phosphorus among its neighbors in the Periodic Table of the Elements
the element phosphorus among its neighbors in the Periodic Table of the ElementsCourtesy modified from Wikipedia
Phosphorus is a very important element in living things. For example, it’s a necessary ingredient in ATP (adenosine tri-phosphate), the energy molecule used by all forms of life. Phosphorus is picked up from seawater by bacteria. All other marine life depends upon these bacteria, either directly or indirectly, for P. Therefore, if you’re bacteria living in the impoverished North Atlantic Gyre, you’d better be really good at getting phosphorus.

And they are!

Oceanographers at the Center for Microbial Oceanography: Research and Education (C-MORE) at the University of Hawai`i have made an important discovery. C-MORE scientists Sallie Chisholm, based at the Massachusetts Institute of Technology and her former graduate student Maureen Coleman, now a scientist at the California Institute of Technology, have been studying two species of oceanic bacteria. Prochlorococcus is an autotrophic bacterium that photosynthesizes its own food; Pelagibacter, is a heterotrophic bacterium that consumes food molecules made by others.

Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.
Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.Courtesy C-MORE
Drs. Chisholm and Coleman took samples of these two kinds of bacteria from both the Atlantic and Pacific Ocean. The Atlantic samples were collected by the Bermuda Atlantic Time-Series (BATS) program. The Pacific samples were collected in the North Pacific Gyre (about 90 miles north of Honolulu) by the Hawai`i Ocean Time-Series (HOT) program. The scientists discovered surprising differences in the genetic code of the bacteria between the two locations:

  • First of all, the Atlantic populations of both bacterial species have more phosphorus-related genes compared to their Pacific cousins. (Picture Atlantic microbes in Superman outfits with a big "P" on their chests!)
  • Secondly, in the Atlantic, Prochlorococcus has different kinds of P-related genes compared to Pelagibacter. Perhaps this means the two microbial species have evolved over time to use different phosphorus sources, to avoid competing with one another for this limited resource.

Drs. Chisholm and Coleman have discovered important micro differences between bacteria of the same species in two oceanic gyres. Now we can better understand how these microbes are working to recycle an important nutrient beneath the whitecaps.

Reference: October 11, 2010 issue of the Proceedings of the National Academy of Sciences

You know you want to know!

First, check out the Household Flux Calculator, and discover your flux score. With your curiosity piqued, keep going and find out how your household activities influence the cycles of carbon, nitrogen, and phosphorus.

Although households are known to influence the energy budgets of cities and countries, few studies have looked at their contribution to environmental pollution. The University's Twin Cities Household Ecosystem Project involves a survey of 3,100 urban and suburban households in Ramsey and Anoka counties and their household emissions. The study centers on a range of behaviors, including household energy use, food choices, vehicle use, air travel habits, pet ownership and lawn care practices. University scientists Lawrence Baker, Sarah Hobbie and Kristen Nelson will discuss the surprising results of this groundbreaking research.

And, yes, they'll answer the question, if you ask them nicely.

Households and Urban Pollution
Tuesday, January 18, 7 p.m. Doors open at 6 p.m.
Bryant-Lake Bowl, Minneapolis
Cost: $5-$12. Tickets available at the door and online at Bryant-Lake Bowl.
Call 612-825-8949 for reservations.

Sep
23
2010

You might be aware of phosphorus, P, as a key ingredient in your lawn fertilizer. Or, perhaps you’ve seen “Does not contain phosphates” labels on your household detergents. If you haven’t seen these labels yet, chances are high you’ll see them soon. Why??

Phosphorus is Useful as Fertilizer and Detergent...

Fertilizer with P: See the N-P-K?  The P stands for phosphorus.  The number 21 below it tells us the percent of P in the fertilizer.  Many lawn fertilizers are now 0% P.
Fertilizer with P: See the N-P-K? The P stands for phosphorus. The number 21 below it tells us the percent of P in the fertilizer. Many lawn fertilizers are now 0% P.Courtesy Malawi MV project work

Phosphorus is a life-supporting mineral, which is why so many fertilizers contain it. Phosphates, the naturally occurring form of phosphorus, help soften water, form soap suds, and suspend particles making them choice detergents. Supporting life and keeping clean would normally be good things, but phosphorus has a dark side too.

... But, Phosphorus Causes Smelly, Dead Eutrophication

Because phosphorus is so good at growing stuff, it is actually harmful to the environment when it becomes dissolved and concentrated in bodies of water. Phosphorus-rich lakes cause algae blooms – huge increases of algae in a short period of time (kind of like the post-World War II Baby Boom, but for algae). Besides being smelly and turning water green, algae “breathe” the oxygen right out of the lake! Stealing dissolved oxygen even in death, algae create hypoxia – low oxygen, which prevents most other living things from surviving in the surrounding area. This whole process, from phosphorus-loading to algae bloom to hypoxia, is called eutrophication. There are other environmental and health risks to phosphorus, but eutrophication is what politicians are talking about around the water cooler these days.

Icky Algae Bloom: Algae blooms occur in nutrient-loaded water bodies and often led to hypoxia in a process called eutrophication.
Icky Algae Bloom: Algae blooms occur in nutrient-loaded water bodies and often led to hypoxia in a process called eutrophication.Courtesy Felix Andrews

Seventeen States Banned Phosphorus in Automatic Dishwashing Detergents

Deciding that euthrophication was yucky, in July, 17 states, including the entire Great Lakes Commission of which Minnesota is a member, passed laws banning phosphates from automatic dishwasher detergent. That might not seem like a big deal, but automatic dishwasher detergent is said to comprise between 7-12% of all the phosphorus making it into our sewage system (source). Previous legislation has limited or banned phosphorus in lawn fertilizers and laundry detergents.

Consumers Asked to Cope

According to a recent New York Times article, some consumers are getting their feathers ruffled as detergent manufacturers re-do their formulas to comply with state laws. The primary complaint is that the phosphate-free detergents don’t clean as well as traditional formulas. Consumer Reports concurred: of 24 low- or no-phosphate detergents tested, none matched the cleaning capabilities of detergents with phosphates. It may be uncomfortable at first, but learning to cope in a low-phosphorus world is already having environmental and human health benefits.

Green Cleaning: There are several line of green cleaning products that contain low- or no-phosphates.
Green Cleaning: There are several line of green cleaning products that contain low- or no-phosphates.Courtesy Becoming Green

Rest assured, industry officials still want your business and are continually improving their formulations. Indeed, the same Consumer Reports article mentioned above rated seven low- or no-phosphate detergents as “very good.” For the curious, there is a multitude of other websites reviewing phosphate-free detergents online. Pre-rinsing and/or post-rinsing have also been cited as ways to deal with phosphate-free dishwashing detergents.

Peak Phosphorus: Another Consideration

If you still aren’t convinced of the switch, consider this: we’re running out of phosphorus like we’re running out of oil. Phosphorus is a mineral, mined from naturally occurring phosphates, and we’re mining it faster than geologic cycles can replenish it. One Scientific American article cites the depletion of U.S. supplies in a few decades (world supplies may last for roughly another 100 years) given current consumption rates. Without phosphorus, world food production will plummet and with a global population soaring towards 9 billion people, that would be a very sorry state of affairs. If we succeed in limiting our phosphorus consumption, say, through eliminating it from household detergents, we may be able to continue using it in fertilizers and thus keep the human population fed well into the future.

What do you think? Is the phosphate-ban worth it?

Jul
22
2008

Eutrophication: Agricultural run-off rich in fertilizers stimulates rampant growth of algae.
Eutrophication: Agricultural run-off rich in fertilizers stimulates rampant growth of algae.Courtesy NASA

Human populations effect lakes

Human sewage and fertilizer runoff effects the health of lakes. It often causes huge algal blooms, kills fish, and creates other problems.

Long term study of "cultural eutrophication" released

For 37 years researchers have examined the best ways to control this "cultural eutrophication" process of lakes by varying the levels of phosphorous and nitrogen added to the lake.

After completing one of the longest running experiments ever done on a lake, researchers from the University of Alberta, University of Minnesota and the Freshwater Institute, contend that nitrogen control, in which the European Union and many other jurisdictions around the world are investing millions of dollars, is not effective and in fact, may actually increase the problem of cultural eutrophication.

Time to rethink current practices for healthy lakes

"David Schindler, professor of ecology at the University of Alberta, and one of the leading water researchers in the world, wants to change current practice in controlling nitrogen runoff by stating that

"Controlling nitrogen does not correct the polluted lakes, and in fact, may actually aggravate the problem and make it worse."

This study done by the University of Alberta, University of Minnesota and the Freshwater Institute appears in the journal, Proceedings of the National Academy of Sciences.

Source: PhysOrg.com

Apr
21
2006

On April 6, officials from Minnesota and Wisconsin signed an agreement designed to reduce levels of phosphorus in the St. Croix River by 20% by the year 2020.

For more information about phosphorus in the St. Croix visit the Buzz kiosk in the Mississippi River Gallery on level 5, or check out our on-line feature.