Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Migrating animals add new depth to how the ocean “breathes”

25.06.2013
The oxygen content of the ocean may be subject to frequent ups and downs in a very literal sense — that is, in the form of the numerous sea creatures that dine near the surface at night then submerge into the safety of deeper, darker waters at daybreak.

Research begun at Princeton University and recently reported on in the journal Nature Geoscience found that animals ranging from plankton to small fish consume vast amounts of what little oxygen is available in the ocean’s aptly named “oxygen minimum zone” daily.


Research begun at Princeton University found that the numerous small sea animals that migrate from the surface to deeper water every day consume vast amounts of what little oxygen is available in the ocean’s aptly named “oxygen minimum zone” daily. The findings reveal a crucial and underappreciated role that animals have in ocean chemistry on a global scale. The figure above shows the various depths (in meters) that animals migrate to during the day to escape predators. Red indicates the shallowest depths of 200 meters (650 feet), and blue represents the deepest of 600 meters (2,000 feet). The black numbers on the map represent the difference (in moles, used to measure chemical content) between the oxygen at the surface and at around 500 meters deep, which is the best parameter for predicting migration depth. (Courtesy of Daniele Bianchi)

The sheer number of organisms that seek refuge in water roughly 200- to 650-meters deep (650 to 2,000 feet) every day result in the global consumption of between 10 and 40 percent of the oxygen available at these depths.

The findings reveal a crucial and underappreciated role that animals have in ocean chemistry on a global scale, explained first author Daniele Bianchi, a postdoctoral researcher at McGill University who began the project as a doctoral student of atmospheric and oceanic sciences at Princeton.
Research begun at Princeton University found that the numerous small sea animals that migrate from the surface to deeper water every day consume vast amounts of what little oxygen is available in the ocean’s aptly named “oxygen minimum zone” daily. The findings reveal a crucial and underappreciated role that animals have in ocean chemistry on a global scale. The figure above shows the various depths (in meters) that animals migrate to during the day to escape predators. Red indicates the shallowest depths of 200 meters (650 feet), and blue represents the deepest of 600 meters (2,000 feet). The black numbers on the map represent the difference (in moles, used to measure chemical content) between the oxygen at the surface and at around 500 meters deep, which is the best parameter for predicting migration depth. (Courtesy of Daniele Bianchi)

“In a sense, this research should change how we think of the ocean’s metabolism,” Bianchi said. “Scientists know that there is this massive migration, but no one has really tried to estimate how it impacts the chemistry of the ocean.

“Generally, scientists have thought that microbes and bacteria primarily consume oxygen in the deeper ocean,” Bianchi said. “What we’re saying here is that animals that migrate during the day are a big source of oxygen depletion. We provide the first global data set to say that.”

Much of the deep ocean can replenish (often just barely) the oxygen consumed during these mass migrations, which are known as diel vertical migrations (DVMs).

But the balance between DVMs and the limited deep-water oxygen supply could be easily upset, Bianchi said — particularly by climate change, which is predicted to further decrease levels of oxygen in the ocean. That could mean these animals would not be able to descend as deep, putting them at the mercy of predators and inflicting their oxygen-sucking ways on a new ocean zone.

“If the ocean oxygen changes, then the depth of these migrations also will change. We can expect potential changes in the interactions between larger guys and little guys,” Bianchi said. “What complicates this story is that if these animals are responsible for a chunk of oxygen depletion in general, then a change in their habits might have a feedback in terms of oxygen levels in other parts of the deeper ocean.”

The researchers produced a global model of DVM depths and oxygen depletion by mining acoustic oceanic data collected by 389 American and British research cruises between 1990 and 2011. Using the background readings caused by the sound of animals as they ascended and descended, the researchers identified more than 4,000 DVM events.

They then chemically analyzed samples from DVM-event locations to create a model that could correlate DVM depth with oxygen depletion. With that data, the researchers concluded that DVMs indeed intensify the oxygen deficit within oxygen minimum zones.

“You can say that the whole ecosystem does this migration — chances are that if it swims, it does this kind of migration,” Bianchi said. “Before, scientists tended to ignore this big chunk of the ecosystem when thinking of ocean chemistry. We are saying that they are quite important and can’t be ignored.”

Bianchi conducted the data analysis and model development at McGill with assistant professor of earth and planetary sciences Eric Galbraith and McGill doctoral student David Carozza. Initial research of the acoustic data and development of the migration model was conducted at Princeton with K. Allison Smith (published as K.A.S. Mislan), a postdoctoral research associate in the Program in Atmospheric and Oceanic Sciences, and Charles Stock, a researcher with the Geophysical Fluid Dynamics Laboratory operated by the National Oceanic and Atmospheric Administration.

Read the abstract

Citation: Bianchi, Daniele, Eric D. Galbraith, David A. Carozza, K.A.S. Milan and Charles A. Stock. 2013. Intensification of open-oxygen minimum zones by vertically migrating animals. Nature Geoscience. Article first published online: June 9, 2013. DOI:10.1038/ngeo1837

This work was supported in part by grants from the Canadian Institute for Advanced Research and the Princeton Carbon Mitigation Initiative.

By Morgan Kelly, Office of Communications

Morgan Kelly | EurekAlert!
Further information:
http://www.princeton.edu

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>