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 Predicting eruptions using satellites and math
28.06.2017 | Frontiers

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>