Return of the salmon
Thanks to intensive sewage treatment measures implemented by riverside communities and industry, the Rhine is gradually overcoming the acute water poisoning over the years, says GUNVANTHI BALARAM.
The Rhine is at once a commercial waterway, freshwater reservoir, tourist attraction and an economic necessity.
FOR nearly a century, the Rhine was dismissed as the "Sewer of Europe". In 1986, it was pronounced "biologically dead". Today, that dead sewer is a healthy river once more, with the five Rhine countries having astonishingly succeeded in cleansing it of its ills. The symbol of the river's recovery is the mighty salmon which swims again in its waters after a lapse of half a century.
Meandering as it does 1,320 km from its Alpine source near Basel to its mouth at Rotterdam on the North Sea, the Rhine has long been Europe's busiest inland waterway. In the 1800s, its waters glittered with silver not of the metallic variety, but of the "fishy" one. But by the mid-1900s, the silver flash of salmon had vanished as the waters had turned into a toxic soup peppered with pesticides from Swiss chemical factories, potassium salts from Alsatian mines, heavy metals from German industries, raw sewage from Rhineside cities and engine oils from cargo ships and as the innumerable new dams and hydroelectric stations all along its banks prevented the fish from migrating. Salmon migrate from the river to the sea when they are about 18 months old and return at the age of about three years to spawn in the riverbed where they were born.
The return of a mascot
The salmon vanished from the Swiss Rhine by the 1930s and from the German Rhine by the 1950s. The return of this pollution-sensitive fish is a salute to the Rhine's clean-up operation. Though successful, the operation has been a long and difficult one, according to Basel-based biologist Dr. Daniel Kuery, whose company, Lifescience, is among the environmental agencies involved in Rhine restoration work in Switzerland.
Though work on restoring the river started officially in 1950, when the International Commission for the Protection of the Rhine (ICPR) was established, it took an ecological catastrophe in 1986 in this Alpine country, he says, to get the Rhine nations truly dedicated to cleaning up and breathing life back into the river.
"A fire in 1986 in the Sandoz warehouse in Basel spewed chemicals into the water that killed over 5,00,000 fish up to 50 miles down the river and triggered a drinking water alarm for 50 million people right up to Amsterdam. The pharmaceutical company, under public pressure, donated 5 million Swiss francs to scientifically cleanse the river and improve living conditions for its aquatic fauna," Dr. Kuery says, as we traverse the Rheinweg in Basel.
"The Sandoz fund brought about the first steps of salmon restoration in the Rhine," adds river ecologist Dr. Armin Peter at EAWAG (the Swiss institute of environmental research which is dedicated to water pollution control) in Duebendorf near Zurich. Switzerland and Germany, egged on by the Green Party, took the lead, and France, Luzembourg and Holland followed suit. "Scared of losing consumer support, other chemical companies also chipped in with multi-million-dollar grants for the Rhine research and rejuvenation. They all wanted to be seen as good guys."
Balancing ecology and economy
The Sandoz scare, which came just weeks after the Chernobyl catastrophe in Russia, enabled the ICPR to set higher goals in its 1987 Rhine Action Plan for Ecological Rehabilitation. The three-phase, 15-year plan aimed at reviving the river by identifying and eliminating the main sources of pollution with a more active regimen of water-quality testing, pollution patrols to keep industry and communities honest, and steep penalties for polluters. "Popularly known as the Salmon 2000 project, the plan promoted the idea that the Rhine is a total ecological system," says Dr Kuery, "a place where salmon, pike, perch, trout and other fish could thrive once more."
So meticulously/strictly have its measures been implemented that "today, oxygen levels are 100 per cent in most parts of the Rhine system an achievement few experts expected 20 years ago," notes a scientist at the ICPR headquarters in Koblenz (Germany). "The river will always be a mainstay of commerce, and we will always have problems to watch out for, but we are optimistic about striking a comfortable compromise between ecology and economy."
Help for the salmon
Electrofishing for salmon in the Birs tributary of the Rhine in Basel.
The 1990s also saw some "fishy" measures also being launched to help back the salmon. Since 1991, over five million salmon fry (very young salmon) have been released into the river. A local fishing club on the Sieg tributary near Bonn was the first to import salmon eggs from Scandinavia, Ireland and Scotland and release salmon fry into the river. The successful experiment was promptly replicated under scientific surveillance by fishery boards elsewhere along the river, including in Basel.
In 2000, Basel's enlightened residents endorsed planned changes in the local landscape that would help the salmon migrate. Along Basel's Birs and Ergolz rivers (Rhine tributaries), the cantonal authorities are currently spending 5 million Swiss francs on restoring the rivers by, among other things, demolishing the old concrete banks and creating natural banks. Ten similar projects in other Swiss cantons are on the anvil.
"Concrete bunds turn the water sterile and leave no room for natural, vegetated spawning banks. As the vegetation on these new natural banks flourishes, both the water quality and the spawning and living conditions for salmon and other fish improves," explains Dr Kuery, as we look at the Birs' newly modified banks. "Though there is no evidence as yet of a naturally reproducing salmon population in the Rhine and it is a long haul to eating fish from the Rhine, electrofishing in the Birs (and in other pockets of the river) shows that the local salmon and other fish populations are on the rise."
(Electrofishing is a technique that allows scientists to determine fish population before a river's restoration and after.)
Rhine ecologists, meanwhile, continually lobbied power stations to build sophisticated "fish passageways" to allow the salmon to migrate. "In 1996, the first salmon caught in the river for decades was hooked just outside the Iffezheim dam near Strasbourg (France), 160 km north of Basel . The fish came from the North Sea but because of the dam could not reach the branch where it was born. Salmon only spawn in the place where they started life," says Dr. Kuery. "It hasn't been easy to convince power station owners to build complex salmon passes, but their resistance is gradually breaking down. A salmon pass has now been built at Iffezheim at a cost of about $6 million, and another one 20 km away at Gambsheim in Alsace will be completed in 2005. Plus, in all other power stations, studies are being conducted to devise how to facilitate fish migration both up and downstream. We will ensure that soon all the fish will be able to get past turbines and sluice-gates, unharmed."
Yes, the Rhine is a parable of hope. And lessons learned on the Rhine are now being applied to other historic salmon rivers, including the Elbe, shared by the Czech Republic and Germany, and the Oder, shared by Poland and Germany. These, in turn, are models for river rejuvenation in other parts of the globe. Certainly, there are valuable lessons here for India, whose much-vaunted Ganga Action Plan has flopped into stagnant waters.
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