Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fossils provide insight into origin of unique Antarctic ecosystem

19.04.2013
The circum-Antarctic Southern Ocean is an important region for global marine food webs and carbon cycling because of sea-ice formation and its unique plankton ecosystem.

The origin of its ecosystems can be traced back to the emergence of the Antarctic ice sheets approximately 33.6 million years ago. This discovery was made by an international team including scientists from the Goethe University and the Biodiversity and Climate Research Centre in Frankfurt, Germany.


A characteristic dinoflagellate cyst found in sediments dating back to the early Oligocene (33 million years ago). © Alexander Houben

Their study, published today in Science, shows that the development of the sea-ice ecosystem possibly triggered further adaptation and evolution of larger organisms such as baleen whales and penguins

The scientists analysed sediment samples from drill cores on the seafloor, which were obtained in 2010 off the coast of Antarctica, as part of the Integrated Ocean Drilling Program (IODP). The cores reach nearly 1000 meters beneath the seafloor and provide new insights into a long gone past. A study published in 2012 demonstrated that subtropical plants covered Antarctica about 53 million years ago. In the course of the following 20 million years, the global climate cooled continuously. The new study focuses on the interval 33.6 million years ago when within a short time an enormous ice sheet covered Antarctica. This changed the life conditions and the ecosystems on the Antarctic continent and the surrounding Southern Ocean dramatically.

Tiny witnesses: Dinoflagellates

The ocean plankton mainly consist of algae, most of which are not preserved in sediment samples from drill cores. In contrast, single-celled dinoflagellates, a group of algae containing organic fossilizable substance, do preserve in sedimentary sequences over millions of years. This makes them a valuable tool to reconstruct environmental.

The researchers found that when Antarctica was sub-tropical and ice-free, the surrounding seas were inhabited by a diverse array of dinoflagellates characteristic for relatively warm climates. However, from the moment that the ice cap formed, the diversity suddenly collapsed, and from that moment, only species occurred that are adapted to temporary sea-ice cover and characterize modern sea-ice environments around Antarctica. They are present in high numbers only when the sea ice melts in spring and summer, and therefore are available as a food source for higher organisms only during a short period of the year.

New species due to food shortage

The seas around Antarctica play a critical role in the food web of the ocean. Algal blooms only occur in summer, when the sea ice melts. These blooms are a key food source for both small single-cell organisms such as certain species of dinoflagellates and for larger organisms.

“The sudden turnover in the dinoflagellate assemblages indicates clearly that the entire plankton ecosystem of the Antarctic waters had changed”, explains Prof. Jörg Pross, co-author of the study and paleoclimatologist at the Goethe University and the Biodiversity and Climate Research Centre (BiK-F) in Frankfurt, Germany. “The explosion of dinoflagellates adapted to a temporary sea-ice cover testifies to an in-depth reorganization of the food web in the Southern Ocean.”

Larger animals higher up in the ocean’s food chain probably adapted their diet because the algal growth season became shorter and more intense. Jörg Pross sums up: „Our data suggest that this change may have promoted the evolution of modern baleen whales and penguins“.

These results stress that major climate change is often accompanied by particularly rapid biological evolution.

For further information please contact:

Prof. Dr. JörgPross
Paleoenvironmental Dynamics Group, Palentology Section, Institute of Geosciences,
Goethe University and
LOEWE Biodiversity and Climate Research Center
Phone +49 (0)69 798 40181 joerg.pross@em.uni-frankfurt.de

or

Dr. Julia Krohmer
LOEWE Biodiversity and Climate Research Center (BiK-F),
Transfer office
Tel. +49 (0)69 7542 1837
julia.krohmer@senckenberg.de

Paper:
A.J.P. Houben, P.K. Bijl, J. Pross et al: Reorganization of Southern Ocean Plankton Ecosystem at the Onset of Antarctic Glaciation, Science, DOI 10.1126/science.1223646

LOEWE Biodiversität und Klima Forschungszentrum, Frankfurt am Main
With the objective of analysis the complex interactions between biodiversity and climate through a wide range of methods, the Biodiversität und Klima Forschungszentrum [Biodiversity and Climate Research Centre] (BiK‐F) has been funded since 2008 within the context of the Landes‐Offensive zur Entwicklung Wissenschaftlich-ökonomischer Exzellenz (LOEWE) of the Land of Hessen. The Senckenberg Gesellschaft für Naturforschung and Goethe University in Frankfurt as well as other, directly involved partners, co‐operate closely with regional, national and international institutions in the fields of science, resource and environmental management, in order to develop projections for the future and scientific recommendations for sustainable action. For further details, please visit www.bik‐f.de

Sabine Wendler | Senckenberg
Further information:
http://www.senckenberg.de
http://www.bik‐f.de

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>