Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Migrating animals' pee affects ocean chemistry

10.10.2014

The largest migration on the planet is the movement of small animals from the surface of the open ocean, where they feed on plants under cover of darkness, to the sunless depths where they hide from predators during the day.

University of Washington researchers have found that this regular migration helps shape our oceans. During the daylight hours below the surface the animals release ammonia, the equivalent of our urine, that turns out to play a significant role in marine chemistry, particularly in low-oxygen zones. Results are published online this week in the Proceedings of the National Academy of Sciences.

"I'm very fascinated by these massive migrations," said lead author Daniele Bianchi, a postdoctoral researcher in the UW School of Oceanography. "To me, it's exciting to think about the effects of animal behavior on a large scale in the ocean."

One might not think that peeing into the vastness of the oceans could have an effect. But the animals – which include tiny zooplankton, crustaceans such as krill, and fish such as lanternfish up to a few inches long – compensate for their small size with huge abundance throughout the world's oceans.

After a nighttime feast near the surface, these small creatures take a couple of hours to swim about 650 to 2,000 feet (200 to 600 meters) deep. Solid waste falls as pellets. The liquid waste is emitted more gradually.

In earlier work, Bianchi made the surprising finding that the animals spend most of their day in low-oxygen water. Marine bacteria consume oxygen as they decompose sinking dead material, creating low-oxygen zones a few hundred feet below the surface.

"The animals really seem to stop in low-oxygen regions, which is sort of puzzling," Bianchi said. Some speculated these zones might protect them from larger predators.

The earlier study also showed that animals actually contribute to these low-oxygen zones by using the little remaining oxygen to breathe.

Researchers next wondered about their other bodily functions.

For the new study, authors mined data from underwater sonar surveys to calculate how many animals are migrating to which depths, and where. Next they gauged the combined effect of their daytime digestion.

Results show that in certain parts of the ocean, ammonia released from animals drives a big part of the oxygen-free conversion of ammonium and other molecules to nitrogen gas, a key chemical transition.

"We still think bacteria do most of the job, but the effect of animals is enough to alter the rates of these reactions and maybe help explain some of the measurements," Bianchi said.

Inside low-oxygen zones, it's still mysterious how bacteria turn so much nitrogen-based ammonia into tight pairs of nitrogen atoms, like those found in air, which cannot be used by plants or animals. The conversion is important because it determines how much nitrogen-based fertilizer remains to support life in the world's oceans.

Researchers typically model low-oxygen zones using factors such as ocean currents, weather and bacterial growth. The new paper, Bianchi said, shows that diving animals, though more difficult to model, also play a role in marine chemistry.

The ocean's low-oxygen zones are projected to expand under climate change, as warmer waters hold less oxygen and decrease oxygen content below the surface. Understanding these zones is thus important for predicting what might happen to the oceans under climate change.

###

The research was funded by the Canadian Institute for Advanced Research, the Canadian Foundation for Innovation and the U.S. National Science Foundation. Co-authors are Andrew Babbin at Princeton University and Eric Galbraith at Canada's McGill University.

For more information, contact Bianchi at 206-221-4402 or danbian@uw.edu

Hannah Hickey | Eurek Alert!
Further information:
http://www.uw.edu

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>