Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

50 years of long-term observation in the Baltic Sea

30.06.2008
Striking evidence of long-lasting changes in the Baltic Sea were documented in a recently published book.

The Baltic Sea is one of the best-investigated seas; data on the status of its marine environment have been recorded over several decades at numerous sites. The resulting valuable long-term data sets encompass a time span of 50 years and in some case even more.

This treasure, which was scattered over several databases, was now brought together in one comprehensive documentation as a monograph published by John Wiley & Sons and edited by the Warnemünde scientists Rainer Feistel, Günther Nausch and Norbert Wasmund. The book includes a CD containing the largest common data set of the Baltic Sea area, encompassing more than 14 million single readings for meteorology, climate, physics, chemistry and biology of the Baltic Sea.

The long-term data set unravels the existence of unpredictable changes in the physico-chemical basic conditions of the Baltic Sea ecosystem, such as in oxygen supply: Although of high importance for the ventilation of the Baltic Sea deep water, almost no inflow of oxygen-rich saltwater from the North Sea occurred during the whole period of the 1980s, while the salinity in the deep water decreased to a minimum in the early 1990s. Ten years later, these effects were also measured in surface water samples. Actually, this is the time scale required for a drop of deep water to make it to the surface.

At the beginning of the 1990s, salt water inflows became more frequent again. But, on the contrary to the events before the 1980s, they now predominantly occurred during the late summer and autumn instead of winter. This seasonal shift is indicated by much higher temperatures of the deep water of the Bornholm and Gotland Basins since 1997. But not only the temperature is influenced by this change: in late summer, inflowing North Sea waters contain much less oxygen than in winter. But, surprisingly, it still can ventilate the deep areas in case they get in contact with the cold and oxygen-rich so called winter water at certain topographical positions in 40 - 60 m depth. This leads to a clear coexistence of ventilated areas and zones of severe oxygen depletion, but also to frequent transitions among these states and related nutrient fluxes.

Nutrient data from the surface water show a drastic increase of nitrate and phosphate in the 1970s, which is predominantly caused by a rapidly growing consumption of fertilizers in agriculture during that time. Later, the nutrient concentrations stabilize at a level twice as high as the natural background values. This "over-fertilization" is reflected by an increase in phytoplankton biomass, however, with a certain time lag. In the Baltic Proper, phytoplankton reached a peak level in the mid 1990s.

The largest part of this wealth of information is represented by the data set available at the Leibniz Institute for Baltic Sea Research. Several generations of researchers of the IOW and its precursor institutions have contributed essentially to our present knowledge. After first expeditions in 1955, a regular observation programme was established comprising five cruises per year with 80-100 stations worked in the southern and central Baltic Sea since then. The results from these monitoring cruises represent the German contribution to the Baltic Sea Monitoring Programme of the Helsinki Commission for the Protection of the Baltic Sea (HELCOM), but provide at the same time a fundamental data pool for the research of the institute in Warnemünde.

Under the auspices of the IOW, in total 64 scientists from Germany, Denmark, Finland, Poland and Sweden contributed on more than 700 pages with their knowledge on meteorology, climate, physics, chemistry and biology of the Baltic Sea. Without such a collection of measurements, the shifts in the physico-chemical basic conditions of the Baltic and the complexity of the processes could hardly be recognized. A profound understanding of these basics allows to assess future scenarios of the ecosystem development. Even the best-investigated sea of the world still can surprise and intrigue scientists.

Contact:
Dr. Rainer Feistel (+49 381 5197 152); Dr. Barbara Hentzsch (+49 381 5197 102)
Leibniz Institute for Baltic Sea Research Warnemünde, Seestr. 15
D-18119 Rostock, Germany
Reference:
John Wiley & Sons, Hoboken, USA (Feistel, R., Nausch, G., Wasmund, N., State and Evolution of the Baltic Sea, 1952 - 2005. A detailed 50-year survey of meteorology and climate, physics, chemistry, biology and marine environment, Wiley 2008).

Dr. Barbara Hentzsch | idw
Further information:
http://www.io-warnemuende.de

More articles from Ecology, The Environment and Conservation:

nachricht Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.

nachricht How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.

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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>