The first thing about oil spills that comes to mind for many are pictures of birds drenched in the black stuff. We feel that the dreaded gunge means death to all living things. Yet there are microbes in the soil, water and even ice that thrive on eating oil.

Oil-degrading microbes play a major role in the research of Sonja Suni, a PhD student who works at the Department of Ecological and Environmental Sciences. She is researching natural methods to clean up oil spills. But cotton grass, a common plant material in peat bogs and a by-product of peat excavation, plays an even bigger role than microbes. “We are testing cotton grass fibre as a material to be used in response to oil spills. We are carrying out tests in four-hundred-litre test tanks, which we have filled with water from the Baltic,” says Suni, as she describes the working environment of her Finnish-Russian team.

Cotton grass fibre is oleophilic and hydrophobic, which means it absorbs oil but is water repellent. “Absorption tests have succeeded well, even exceeded our expectations. The absorption cap-acity of cotton grass fibre is two or three times better than that of the synthetic materials on the market,” says Suni. Cotton grass fibre is also far more environmentally friendly than the materials currently in use. The sorbents available are usually made of oil-based polypropylene. “They become hazardous waste after use, whereas cotton grass fibre and the oil it absorbs can easily be burnt or composted, left for ordinary soil microbes to decompose. If there is a need to accelerate the decomposition, the microbes’ performance can be boosted by suitable nutrients or using an electric current to warm up the waste.”

“I wish we didn’t need it” 

Tank tests have shown that cotton grass fibre helps the survival of organisms after diesel spills – both in warm waters and in test conditions simulating winter. Plankton, mussels and other creatures fare well even if a used, dirty cotton grass mat is left in the water to wait for the gradual degrading of the oil.

Suni has mixed feelings about the next stage of the tests. Although it will be interesting to finally see how the cotton grass fibre works in a real situation, nobody wants an oil catastrophe. When one adds up the tonnes of oil shipped in the Baltic by tankers, it seems inevitable that there are large-scale challenges ahead.“Cotton grass fibre is not the solution for accidents in which thousands of tonnes are spilled, although it can support the clean-up operations after the worst catastrophes. It can be used as the sole method in small and medium-sized accidents and deliberate spills,” says Suni.

She hopes that the results produced by her team will soon lead to product development and end up in commercial production in the form of oil booms or sorbent fibre mats. “It would be great if we could engage oil-response authorities in co-operation with product developers at the early stages of productisation. Practical experience is extremely valuable.”

Thousand-year-old fibres 

Peat is an organic soil type that forms when plant material decays in anaerobic conditions. A peat bog has a live layer of no more than a few dozen centimetres, beneath which brews plant debris which is hundreds if not thousands of years old, including cotton grass. The natural stores of peat in Finland alone measure 70 billion cubic metres. Finland may often be dubbed the land of forests, but it would be more justified to call it the land of bogs: the peat reserve of the country is 35 times as large as its timber reserve.

Peat has previously been a significant energy source in many Northern countries. In Finland and in particular in Ireland it still is. The waxy and therefore water-repellent cotton grass fibre is not quite suitable for energy production, so it is practical to separate it from the peat before combustion.

At home in Sphagnum bogs, pine fens and oligotrophic treeless mires, cotton grass has been used for blankets and clothes at least in the 19th century. The leaf sheaths that have soaked in the bog can be mixed with wool cotton or silk and made into textiles that are warmer than lamb’s wool. After the treatments by soil bacteria, the fibre is antibacterial, anti-static and it absorbs odours and salts, which is why it is used for making bed linen and mattresses and similar products for hospitals. In recent years, the plant has been used as an insulating material in replacement of glass wool and for manufacturing waste-water filters.

The sad remnants of a burnt bog 

Harri Vasander, professor in peatland forestry, is strongly in favour of using cotton grass fibre in textiles and oil response materials. Although only half a per cent of the peat in the Finnish soil is cotton grass, it still means there is plenty of it. Vasander thinks peat also has its place in energy production, at least when paired with wood.

“Modern methods enable the extraction of peat in smaller and smaller areas, so that the surrounding environment is not disturbed as much as before.

Exploiting peatland can, however, be destructive, the professor points out. “We should wake up to the fact that in Finland, the eutrophic fens, virgin spruce mires and the undisturbed biological systems ranging from peatlands to mineral soil forests are shrinking.” Agriculture and forestry are turning peatlands into mineral soil. In global terms, the situ-ation is even graver. The transformation of peatlands may accelerate global warming. Some of the changes have reached a point when it is too late for preventive measures. For example in Siberia and Canada, the melting permafrost bogs will be releasing substantial amounts of me-thane over the next few years.

All is not lost, however; there is still a lot to be done. It is vital that areas of peatlands are protected and that the mysteries of their ecosystems uncovered. “The great peatland fires in Indonesia in 1997 and 1998 were a definite wake-up call to many. The climate effects were evident in the clear peaking of carbon dioxide levels, in addition to which the direct health-related and economic repercussions were dramatic. Companies were less eager to invest in the area and tourism suffered,” says Vasander. “After the catastrophe, research in the field has become of greater interest to financiers.”

Not a grain of rice 

More thorough consideration would also be in place when planning the cultivation of cleared peatlands. It depends on the chosen plant how much the groundwater level of the area needs to be lowered. The differences are significant, according to the professor. But regardless of whether the water level is lowered 35 or 70 centimetres, cultivation will turn a substantial amount of peat into carbon dioxide.

Vasander has had the opportunity, or duty, to join several peatland restoration projects. In the North, in the Boreal peatland environment, the work proceeds fairly smoothly, but projects in tropical rainforest swamps suffer from a lack of knowledge and the undertaking is far greater.

“Damming up water is expensive and difficult. Moreover, restoration work in the tropics takes place often in harsh conditions, as the felling of trees has changed the previously stable temperature conditions in these areas completely. For example, in our Borneo project, dams have been built in conditions that not even the locals could endure, in over forty degrees centigrade.”

The Borneo project with all its hardships was a good example of the risks of exploiting peatland,” Vasander says. “The idea was that immigrants from the overpopulated Java and Madura would start cultivating rice. Not a grain of rice ever ripened, but instead ethnic conflicts and terrifying fires in cut and drained peat swamp forests broke out. The immigrant workers, who had sold everything to start a new life, found themselves in a dead end and had no choice but to start illegal felling and gold digging.”