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A new method to detect toxic waste in rivers

If a firm tips waste into a river and a physical/chemical analyses is done to detect pollution, with the passing of some days or just some hours, water can sweep the pollutants away and the results would be negative. The problem is this kind of methodologies is very isolated and is not effective with time.

For this reason a reserach group fron the University of Granada has developed a new method to measure water quality, which have extended throughout the Peninsula (Spain and Portugal), some European countries like Italy and Greece, Northern Africa countries (Morocco, Algeria and Tunisia) and several countries of Latin America like Colombia, Brazil, Panama, Venezuela or Argentina.

According to Professor Javier Alba-Tercedor, responsible for the «Biology and Animal Ecology of Lothic Aquatic Environments» research group, the most important about the so-called Method IBMWP (Iberian Biomonitoring Working Party) is that includes a full analysis of the ecological state of water: It does not limit to physical/chemical parameters, but it also involves the study of the organisms which inhabit it, which act as watchmen 24 a day. «In addition, a community of macroinvertebrates takes about a month to recover. That is the time we have, for example, to know if there has been a dumping or any other alteration in a river», the biologist explains.

The IBMWP Method

Professor Alba-Tercedor emphasizes that the main advantages of this new method of water quality evaluation are its low cost, application speed and reliability.

According to the IBMWP evaluation index of water quality, the research team directed by Professor Alba Tercedor has just finished, together with scientists from the universities of Barcelona, Vigo, Murcia, Almeria, Balearic Islands and of the CEDEX of Madrid, a wide study on the ecological state of the rivers of the Spanish Mediterranean. The methodology used has allowed to know the state of river´s water according to a quality scale which fluctuates among ranges from 1 to 5: ‘Very good’ (not polluted or not noticeably polluted); ‘eutrophy, moderately polluted’; ‘polluted’; ‘very polluted’; and ‘extremely poor’ (strongly polluted).

According to these parameters, after studying 12 basins and taking samples for three years in 150 sampling stations, overall data indicate that about 30% of the studied points show clear signs of pollution (ranges 3 to 5), with clear seasonal variations. The Guadalfeo river is one of the river resources wich present a better state, as 82% of its waters are «very good» (39% range 1) or «eutrophy» (43% range 2).

Pollença, Segura and Aguas are other of the best quality rivers with levels of 78%, 80% and 72% respectively.

Rivers like the Besós and the Almanzora are in the exact opposite, with 29% of their water in a «very polluted» or «extremely poor» state. The general situation of the rivers of the analysed area is quite positive, as 70% of the water is between 1 and 2 levels (very good or moderately polluted).

A seasonal study of river situation has also been carried out. According to the results, water is less polluted in spring and summer and mor epolluted in autumn and winter. «In the case of the river Guadalfeo, for example, it is obvious that Sierra Nevada´s thaw has a beneficial effect «, the Professor says.

The Guadalmed-I project, which has been finished in June of this year, will go on for three more years with a second phase (Guadalmed-II), which will study the typology of Iberian Mediterranean rivers according to the guidelines required by the new Water Framework Directive; a prediction system (MEDPACS) will be developed to predict the conditions rivers should present (incluiding the biological community) of very polluted rivers and set recovery objectives.

Javier Alba-Tercedor.
Dpt. of Animal Biology and Ecology.
Phone number: 958 244015.