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Water en land

Mens en Milieu

Marine bacteria, www.nioz.nl, Koninklijk NIOZ

Bacteria

Bacteria are so small that they can only be seen with a powerful microscope. However, they have a tremendous influence on all other organsims. The easiest way to recognize the various species is by the way they react to chemicals. The sea is full of bacteria, millions per liter seawater. Scientists estimate 5 to 10 million different species of bacteria living in the sea. Without bacteria, salt-tolerant plants would not be able to grow.

On Texel


, Sytske Dijksen, www.fotofitis.nl

Water found in ditches in the woods and puddles on marshes sometimes have a thin layer floating on the surface that looks like oil. Most people are so accustomed to seeing dirty water that they assume this film is a sign of pollution. However if you stick your finger in it, the film breaks apart into small specks whereas a film of oil remains more or less an entity. This film is an iron bacteria and totally natural. Water on Texel contains a high amount of iron. So it's not strange to find this bacterium here. In the picture above, you see footprints from a bird in the iron bacteria.

  • Makes some sick, helps others to prosper

    Some bacteria species cause illnesses. Several examples are fire blight in hawthorns, Lyme disease transferred to people by ticks and contamination of oysters and mussels with Campylobacter. Without bacteria, viruses cannot exist. Viruses make up an important group of pathogens.

    Rhizobacteria are species that grow in the vicinity of plant roots. There are even salt-tolerant rhizobacteria species that promote plant growth, first discovered among glasswort roots. Scientists in India were able to isolate the rhizobacteria and found that they even advance growth when the salt concentrations are high. This is good news for farmers whose land is plagued by salty seepage.

  • Important cleaners

    Bacteria form the 'garbage collectors' everywhere in nature. They are major decomposers of dead plants and animals so that the elements can be used again in the food cycle. Without this recycling service, life on earth would be impossible. You even find bacteria in the oxygen-depleted bottoms on tidal flats, where they use sulphuric compounds in the mud to produce the necessary energy to grow.

    In addition to 'collecting the garbage', bacteria also clean up waste. They are essential in purifying wastewater. They grow on the organic material and nitrogen and phosphate compounds, forming flakes which sink to the bottom. This mud is easy to remove from the water. On Texel, the mud is dried and sold for various industrial processes, such as cement-making. There is also an extra water purification stage on Texel, the helophyte filter. Again, bacteria play an important role by removing even more organic material out of the water, resulting in practically drinkable water.

  • Bacteria as oil consumer

    Bacteria don't just degrade dead plants and animals. They also help to degrade oil. During the oil disaster in the Gulf of Mexico in April 2010, bacteria performed excellent work within a short period of time. It took months to plug the leak. However once that succeeded, the bacteria consumed the oil much faster than ever expected: within three weeks. The scientists who performed the studies don't totally understand how an organism which usually needs nitrogen and phosphorus to grow and make new cells is able to work so quickly in a material where these elements were practically lacking. Nor is this reason to think that oil spills are not dangerous for nature. The water may have been cleansed of the muck, however many animals had been killed beforehand. In addition, the greenhouse gas CO2 is produced by the bacteria in the process of degradation.