Greece's dead sea

While there is no consensus on the root cause behind an algal bloom that haskilled millions of fish in the Maliakos Gulf, the season is nevertheless overfor hundreds of fishermen

DAMIAN MAC CON ULADH

Under the microscope: the Chattonella marina specles of algae

AS FISH-eating Greeks near the end of their religious fasting, fishermen and their wider community dependent on the Maliakos Gulf face a bleak year ahead as an algal bloom, now two months old, continues to devastate stocks.

Surrounded on its northern, western and southern shores by the prefecture of Fthiotida, the Maliakos Gulf is one of the prime fish-farm regions of Greece. It is estimated that millions of fish, both wild and farmed, have died since the first dead fish were noticed by local fishermen in late January.

From late February, further fish kills were reported from all sides of the Maliakos, in central Greece, from the municipality of Rahes on its northern entrance to Kamena Vourla and Agios Konstantinos in the south.

According to a Greek daily newspaper, one fish farm has lost over three million fish.

"We're talking about many tons of dead fish in general," said Kalliopi Pagou, a researcher at the Institute of Oceanography of the Hellenic Centre for Marine Research (HCMR).

Earlier this week, the HCMR identified phytoplankton from the genus Chattonella as the source of the mass kill. As Pagou explained to the Athens News, the "highly toxic" Chattonella effectively chokes fish within a few hours by forming thick mucus on their gills.

"Chattonella also kills through the toxic compounds it produces, such as neurotoxins, which affect the nervous system, and superoxides that also damage the gills."

One of the most unusual characteristics of the disaster, according to fishermen, is that it has also killed demersal fish, or bottom feeders, such as sea beam, sand steenbras, bass, bream and becker.

Pagou said Chattonella species are known to produce a cyst when conditions for its survival are no longer present. These dormant forms of the cell then fall to the seafloor, but she says she has no evidence to suggest that this is what happened to the demersal stock in the Maliakos this time around.

The researcher said that there have been several incidents of Chattonella internationally, most commonly in fish farms. The Maliakos case is the second in Greece, the first occurring on the coastline of the Larissa prefecture in 2007, in a channel where several fish species were cultivated.

While scientists have yet to find the cause of the current Chattonella algal bloom, they do know the microorganisms thrive when conditions are ripe.

"All phytoplankton species develop in suitable environments where conditions are mainly dominated by nutrients," says Efstathios Balopoulos, director of the Institute of Oceanography.

According to Fthiotida Prefect Thanasis Heimaras, the algae are "always present in the sea", but that the recent heavy rainfall, which came after five years of scant precipitation, has increased the eutrophication, or increase in chemical nutrients, of the water.

The nutrients in question could come from organophosphates - the basis of many insecticides and herbicides - food chemist Yiannis Zabetakis told this newspaper.

"When organophosphates reach the sea through rivers or from the land, then certain algae have the nutrients to grow," Zabetakis said, identifying nitrogen as one of the most vital ingredients for the algae.

Untreated human waste in Lamia could also be to blame.

"As it only has a two-stage and not the necessary three-stage clarification system," Zabetakis says, "one can say that the 'treated' wastewater from Lamia is rich in nitrogen."

Environmentalists in Fthiotida have long campaigned for all of the prefecture's sewage to be properly treated. According to the SOS Maliakos citizens group, formed in response to the fish kill in the gulf, the prefecture's two biological treatment plants can only serve 60,000 of Fthiotida's 180,000 inhabitants. The rest of the waste flows untreated, the group says, into the sea or the 63 tributaries and main course of the River Sperheios.

Although its delta is one of Greece's biggest Natura 2000 nature reserves, covering a total of 340km2, the valley surrounding the River Sperheios has been the scene of the development of hundreds of polluting facilities, including factories, olive oil presses and industrial livestock operations.

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Danger to humans 'unknown'

The Chattonella outbreak has killed large, bottom-feeding fish as well as smaller fish from higher aquatic zones

The effects of Chattonella on humans are "unknown" because "humans do not usually eat dying or ill fish", says Kalliopi Pagou, a researcher at the Institute of Oceanography of the Hellenic Centre for Marine Research (HCMR).

Nevertheless, when contacted by the Athens News, Thanasis Heimaras, the prefect of Fthiotida, which surrounds the Maliakos Gulf on three sides, said he had no problem eating fish from the area.

"The water of the Maliakos could not be cleaner. After checks done by 40 scientists representing, among others, three ministries ... and the HCMR, it has been proved, firstly, that the waters of the Maliakos are clean and that people can bathe in it and, secondly, that its fish are fit for human consumption."

Referring to fish affected with Chattonella, Heimaras said: "As long as they are still fresh, these fish are good to eat."

The former New Democracy MP said that he based his opinions on a report written by professor Yiorgos Nikolaidis of the University of Thessaloniki's biology department.

Heimaras pointed out that he recently welcomed Health Minister Dimitris Avramopoulos to the area on an unrelated matter.

"We all ate fish," Heimaras said, "There is no danger to public health."

However, eating shellfish from an area infested with toxic algae - including two species of Chattonella, Chattonella antiqua and Chattonella marina - presents a danger to human health, says the Food Safety Hazard Guidebook, co-authored by Richard Lawley.

Published in the United Kingdom by the Royal Society of Chemistry in 2008, it states: "Any filter-feeding shellfish in water affected by a toxic bloom are likely to accumulate high levels of toxin quite quickly as they feed on and digest the algal cells. Thus, shellfish harvested from such waters carry a high risk of toxicity."

The species of Chattonella affecting the Maliakos Gulf has yet to be identified.

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Fisherman devastated

An algal bloom, like this one on the shores of the Maliakos, is usually an indicator that something is amiss

The fish kill in the Maliakos Gulf has been devastating, according to professional diver Tassos Kypraios.

"All the people are very worried," Kypraios says. "They don't want to go to the sea, eat fish, and fishermen haven't worked for two months."

Kypraios is scathing in his criticism of local authorities for "doing nothing".

"They're just trying to say it's ok, it's nothing - they're trying to sweep the problem under the carpet," he told the Athens News, saying people are particularly worried because of the lack of information on what they should do as regards their own health.

Industrial pollution has long been an issue in the Maliakos Gulf and Sperheios River, he says, but authorities have been reluctant to tackle it because "they're afraid they'll lose votes if they do".

Kypraios, who earns his living diving for shellfish, says he has a ton of live shellfish gathered on the seabed but cannot find buyers. "The tavernas and wholesalers aren't interested, so I've no option but to let the stock go free."

Like hundreds of fisherman around the gulf, he has no idea how he's going to pay off his bank loans. He recently borrowed 100,000 euros to buy a boat.

ATHENS NEWS , 17/04/2009, page: A07