Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ocean warming and oxygen loss are putting marine life under more and more pressure

05.06.2015

If you want to live, you need to breathe and muster enough energy to move, find nourishment and reproduce. This basic tenet is just as valid for us human beings as it is for the animals inhabiting our oceans. Unfortunately, most marine animals will find it harder to satisfy these criteria, which are vital to their survival, in the future.

That was the key message of a new study recently published in the journal Science, in which American and German biologists defined the first universal principle on the combined effects of ocean warming and oxygen loss on the productivity of marine life forms.


The Polar cod Boreogadus saida.

Photo: Hauke Flores, Alfred-Wegener-Institut

Their conclusion: as climate change progresses, these animals will be hard-pressed to satisfy their oxygen and energetic requirements in their changing native habitats. As a result, these species will migrate to cooler regions or deeper waters, ecosystems will be disrupted, and the diversity of species will decline.

In order to be able to make more precise and globally applicable prognoses concerning the effects of climate change on life in our oceans, marine biologists have long sought to find universal principles that would allow them to describe the living conditions in the oceans and at their borders. In this regard, one of the key questions is: How will the warming of the oceans and resultant decrease in dissolved oxygen impact marine life forms’ productivity?

As marine biologist Prof Hans-Otto Pörtner from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Science, who co-authored the article, explains, “If an animal has to do more work, it costs energy that it somehow has to produce over and above its resting metabolic rate. Marine life forms generate this additional energy by breathing and thereby taking up more oxygen. However, their ability to do so depends on two factors: the water temperature, and how sensitive the species is to lack of oxygen.”

In their new study, he and his American colleagues Curtis Deutsch, Brad Seibel, Aaron Ferrel and Raymond B. Huey calculated the ability of selected animal species to increase their metabolic rate, then examined that ability in relation with the temperatures and oxygen concentrations in the world’s oceans. This approach allowed them to create a metabolic index for each species, which sets clearly defined limits for oxygen-breathing sea life:

“Marine animals like eelpouts, rock crabs and Atlantic cod can only survive in environments with enough oxygen for them to increase their metabolism to between two and five times their resting metabolic rate if need be. Every species has a certain maximum temperature to survive, and a certain minimum oxygen level, and the two requirements are related,” says lead author Curtis Deutsch from the University of Washington.

As such, the ongoing climate change poses the following problem for marine animals: the warmer the water gets, the less oxygen it can absorb and store. At the same time, in warmer water the animals will need more energy and oxygen to maintain their resting metabolic rate. This means the warmer the oceans become, the less able its inhabitants will be to boost their metabolism to between two and five times their resting metabolic rate, which is what allows them to move, seek food and reproduce.

“If the oxygen level in a given region of the ocean drops below a species’ minimum requirements, it forces the animals to abandon their native habitat. This combines with the effect of warmer temperatures. Since animals evade to cooler regions, their habitat shifts towards the poles or to greater water depths. In Atlantic cod and many other fish species, we can already observe the shift now,” says Hans-Otto Pörtner.

In their study, the authors provide habitat-shift prognoses for all latitudes. As Hans-Otto Pörtner adds: “Further, the phenomenon is even more pronounced in those regions hit by additional oxygen loss, for instance due to increasing water stratification or because human beings release more nutrients into the ocean, promoting the growth of oxygen-stealing microorganisms.”

The researchers expect to see the most apparent changes in the polar seas. “The water in the Arctic and Antarctic Oceans is extremely cold, but also very rich in oxygen. Thanks to evolution, the animals living there have adapted to these conditions and will have little chance to adjust when the combination of warming and lower oxygen levels hits. Instead, species that immigrate from areas with higher water temperatures and lower oxygen concentrations will establish themselves and displace the native polar species,” says Hans-Otto Pörtner.

In the northern Pacific, for example, researchers are already observing a more extreme drop in oxygen concentrations than was expected due to warming alone. In this type of ocean region, the species’ geographic range is reduced drastically, which of course also means significant consequences for the fishing industry.

From a research perspective, the new metabolic index concept can potentially facilitate better prognoses. “We now have a universal approach that allows us to more precisely identify climate-related changes in the geographic range and productivity of a given species,” explains Hans-Otto Pörtner. Now it’s up to the scientific community to investigate the metabolic index and its limits for further species; if they do, Pörtner is confident that: “Bit by bit, we’ll arrive at a far more complete image of what we outlined in our study.”

Notes for Editors:
The study will be published on Friday, the 5th of June 2015 in Science with following title:
Curtis Deutsch, Aaron Ferrel, Brad Seibel, Hans-Otto Pörtner, Raymond B. Huey: Climate change tightens a metabolic constraint on marine habitats, Science 5-Jun-2015

Printable images can be found here: http://www.awi.de/en/news/press_releases/

Your contact in the AWI media team is Sina Löschke (Tel: +49 471 4831 2008; E-Mail: medien(at)awi.de).

The Alfred Wegener Institute conducts research in the Arctic, Antarctic and oceans of the high and mid-latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctica. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.

Ralf Röchert | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>