Feature 02 Sep 14
Zander – predatory invasive fish that have been decimating local stocks in recent years – appear to have met their equal, at last.
|Lake Fierza | Photo by : Altin Raxhimi|
In February 1985, when fisherman Kamber Kapica cast his net between ice floats in the Fierza Lake, he caught sight of two or three fish the size of a palm he did not recognize.
Curious about the catch, Kapica took one of the fish to a biology student at the fishing station in the nearby town of Kukes, who identified it as Styzostedion lucioperca, better known as the zander.
The student told Kapica that the fish had most likely come from Yugoslavia, possibly via a leak in a reservoir in Kosovo.
As little or nothing used to enter Albania under the Stalinist regime of dictator Enver Hoxha, they nicknamed it among themselves the “Yugoslav fish.”
A few years later, the zander had spread across Lake Fierza, the first of three ponds created by damming the River Drin in northern Albania to produce electricity. The invasion posed a threat to small native species of fish like the bleak.
According to Arben Cinari, chair of the Shkodra fishermen’s association, the zander was originally contained in Lake Fierza but then penetrated Lake Koman, the second pond, through the Lake Fierza dam on the Drin River, in the 1990s.
When heavy rains and snow threated to overtop the second dam in 2010, the authorities opened its spillways and numbers of the fish sneaked into Lake Vau i Dejes. A few have even been caught in the Drin itself.
“We are nervous about it. We don’t know the effects, but that it is a cruel fish,” Cinari said.
In a study of the zander published in 1989, two years before the Communist regime collapsed, Albanian biologist Shaban Memia, the student who first identified it, notes that in regular catches they would find as many as 20 bleak in the stomach of one zander.
“It is a fish that needs to eat seven kilos of other fish to gain a kilo of weight,” Memia remarks.
The numbers underline the zander’s predatory nature and the threat it poses to local species.
Biologists feared that it was a threat to the ecosystem and would decimate the bleak, which were being harvested for the canning factories on the Albanian coast.
Zander is native to freshwater and brackish habitats in western Eurasia. Closely related to perch, it has an elongated body and head and a spiny dorsal fin.
Spase Shumka, Albania’s top fish conservationist, believes the it was introduced to western Yugoslavia in the 1950s to populate the reservoirs.
“Now it has also settled in the Neretva,” Bosnia’s main river, Shumka says.
Biologists have been trying to make sense of its impact on the ecosystem.
“If it has reached Albania, it is a pity,” said Predrag Simonovic, a Belgrade ichthyologist who recently completed a regional study of invasive fish species.
“You cannot even do away with it, unless you want to use ultimate means, like rotenone and other pesticides,” he added.
Transferring freshwater fish from one river or water mass to another is almost as old as civilisation.
Roman legionaries spread carp across Europe, and medieval monks replenished their ponds with spawn from other waters.
The practice took on new importance with the industrialization of the West in the 19th century, when fish farms were set up to improve the food base, and amateur fishing became a popular hobby among the new leisured classes.
Even landlocked countries, like Czechoslovakia or Hungary, built sound businesses with freshwater fish farming. Neither surpassed China, whose aqua-culture business accounts for half of the sales and 60 percent of the amount of translocated fish.
In the late 1950s, Albania was becoming China’s pet friend in Europe and began to receive species of the carp family from the Amur River that China shares with the Soviet Union.
After Albania fell out with China in the early Seventies, Chinese carp were replaced by Hungarian purchases, but these were also tightly controlled.
The zander sneaked in regardless. Four years after it was discovered, it made up a fifth of the catch in Lake Fierza, and began to be sold in local markets and exported.
The zander had begun its march westwards and southwards in the continent much earlier.
From rivers on the Eurasian side of Russia, it was introduced in the late 19th century to Western Europe. By 1860 it had entered Germany and The Netherlands, in the late 1880s it was present in Lake Annecy in southern France. In 1890, a British lord brought it to East Anglia to boost recreational fishing.
After being to introduced to Yugoslavia in the 1950s, during the Bosnian war of 1992-95, it also found a way to escape the fish farms located around Bosnia’s iconic Neretva River.
The Adriatic Sea drainage area “has a remarkable degree of endemism in freshwater fish fauna,” says Simonovic. Introducing alien species like the Zander is a “distinct insanity which is allowed without any concern about the either the loss, or compromising of that.”
The zander is not only a concern for regional biologists. In 2008 it was listed as one of the top ten invasive species in the United Kingdom, where the authorities have since all but eradicated it.
Spain has punished any transfer of zander from existing isolated reservoirs to other fresh waters since 2010.
There are stories about how, when it was introduced to an Anatolian lake to yield fillets for export, in no time it had eaten all the carp, and its own population decimated, causing the canneries to close.
“When the zander has nothing else to eat, it eats its own,” says Arben Palushi, a fisheries specialist in Kukes. “It’s a cannibal!”
From predator to tasty meal
By the late Eighties, the zander had established itself at the top of the food chain on the Drin River with a vengeance.
Its success in establishing itself is down to a number of factors, one of which is that it is adapted to life in slow-flowing, sparsely vegetated, rather murky waters.
But the zander has its weak point. Its firm but tender meat with few bones and delicate flavor, is suitable for fillets. The main way to cook it is to grill it.
Shumka has eaten it at near Podgorica, has tasted a dish from Lake Dorjan in Macedonia and has supped on it in the Czech Republic.
“You can’t believe how nice it goes lightly grilled with vinegar on top,” he told me one day in a Tirana bar, recalling his own recipe.
The zander is also a prime product for restaurants in Kosovo that cater to international officials, and has become a favorite catch for fishermen in Kukes region.
After the collapse of Communism in Albania the state-owned fisheries and canning factories closed and demand for bleak fell. But local businessmen found new markets for its predator.
“By then the zander was sold in tonnes annually to Italian and Swiss markets by new entrepreneurs who took it to the Milan wholesale fish markets,” Palushi, the biologist, recalls.
Local fisheries have given way to an armada of independent fishermen who have little respect for regulations and who use explosives and even electric generators.
In Kukes they have experimented with dynamite since the late 1980s, stolen from nearby mines. When that ran out, they began making cheaper explosives bottling nitrate fertilizers.
“There is at least one explosion every night on the Lake Fierza,” says Palushi, who was the region’s environmental chief until 2013. “Last year, I counted more than 500.”
Besides explosives, a more effective and spectacular method of extermination has taken hold.
Fishermen take an electric generator and stick the two wires in the water, which kills or stuns all the fish between the wires.
As a result of abusive fishing techniques, not only the bleak but its mighty alien predator are under threat. Zander catches have fallen drastically of late.
“The days when the fisherman would make a catch of ten kilos are old story,” says Palushi.