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 Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>