Minuscule marine plankton

Text of Anita Buma (translated by Knowledge Debate)

In the North Pole-area the much-discussed climate change is well visible. The environment of tiny marine algea and bacteria changes in many ways: the global warming results for example in a faster melting of sea-ice at the end of the winter. This plays havoc with the timing of many biological processes. Excactly during this time of the year the ozone layer is very rarefied. In spring is therefore an intensified risk of damage by UV-light. In the coastal areas other phenomenons occur: the amount of rainfall and meltwater from nearby glaciers and rivers rises and that’s why seawater sweetens on the surface. Above that the temperature of seawater rises. Because of this a strenghened ‘stabilisation of the watercolumn’ occurs: the warmer sweeter water hampers the mixing with the upper layer by the wind. The water gets moreover more muddy because of the input of glacier and riverwater. Therefore is less light available under water to feed the foodchain with solar energy.

Two groups of organisms are the most important ‘motors”of the sea ecosystem. Firstly the marine micro-algae, one-celled algea that make organic materials with the aid of sunlight and the process of fotosynthese. This so-called fytoplankton forms the base of the entire foodchain in the sea. Secondly bacteria see to an effecient breakdown of died organic material into nutrients reusable by algea. The mentioned consequences of climate change will effect marine biological production and breakdown, firstly by changes in the underwater-lightclimate.

Since a few years the above theme is studied in the Arctics by researchers of Ocen Ecosystems of the University of Groningen. Special techniques are used to study the composition of algae and bacteria. These techniques are based on the comparison of DNA patterns, because this is a very accurate way to distinguish similar tiny organisms: a sort of CSI-approach.

In may and june 2007 Willem van de Poll and Roald Visser studied the effects of melt water on the fjord system. These measurements will be connected with the measurements of the production and species composition of fytoplankton and bacteria.  In so-called manipulation-experiments the strenghtened melting is also imitated. After that the effects on plankton are studied.  The researchers stayed at the German-French research base Koldewy, in international research village Ny Alesund.