With 60 Appellations (AOC) and more than 100,000 hectares of vines, the region of the Gironde (which includes Bordeaux) is the largest wine region in France. The Gironde estuary dominates the whole region affecting the climate, terroir and therefore its vintages. Much of the land occupied along the rivers - particularly the Gironde - are classified estates (under the 1855 Classification). The Gironde itself is the confluence of two main rivers - the Garonne and the Dordogne. The former rising in the Spanish Pyrenees more than 600 kilometers away, the latter in the mountains of the Auvergne almost 500 kilometres to the east in the Massif Central. After 100 kilomotres the Gironde empties into the Atlantic Ocean and it is this maritime climate which provides the more moderate winters and variable summers to the wine-growing areas affected by the river which runs through it. The appellations extend to both sides of the Garonne and the Dordogne rivers and the lands in between. The left bank, referring to the left bank of the Garonne (Medoc, Pauillac); the right bank (Pomerol, St-Emilion), referring to the right bank of the Dorgdogne have between them the Entre-Deux-Mers (between two seas), also the birthplace of the ocean explorer and environmentalist Jacques-Yves Cousteau. 'Left bank' and 'right bank', confusingly, does not refer to the same river. The region also happens to be home to Europe's longest beach - the Côte d'Argent.
The author, and Simon, professional fisherman (retired) and winegrower, make a trip on the Gironde. This viticultural estuary is also an migration axis for birds and fishes. Whilst navigating and fishing the river, the ecologist and fisherman discuss the evolution of the fluvial-estuarine system of the Gironde in terms of the water quality; the richness of the fauna; the degradations suffered and the current pressures are put into the context of the political actions taken to preserve the environment, and the way of life.
When Simon invites me on his filadière, a local traditional fishing boat of the Gironde estuary, I like to listen to his stories about this wild place which he knows so well.
The sun is already high. Mindful of any instructions from this old professional fisherman, my eyes are lulled by the scenery of the river banks and the immensity of these muddy waters. The Gironde is a grandiose territory, one of the largest among the macro-tidal estuaries in Europe. This is the meeting place of ocean water, the Atlantic, and fresh water from the Dordogne and the Garonne: a place of transition. My hand carelessly drags through the water, barely transparent on account of the four to five million tons of suspended solids that accumulate in this natural area. The strong force of the tide pushes saline waters upriver which are submerged below the outflowing river. This creates a turbulence which results in the resuspension of sediment and other particulates present on the river bed. At the same time, dissolved particles flocculate as they come into contact with the sea water passing up river. All of these forces results in elevated levels of suspended particulates known as the 'estuarine turbidity maximum' – the 'bouchon vaseux'.
“You see, the Gironde estuary isn't simply the largest in Europe, it's also one of the biggest migratory routes in Europe." I smile quietly; there's still that Chauvinist side of Simon which emerges from time to time. "This is an ideal route for migratory birds .... - Hey! Look! Above the marshes, a white stork! ". Hardly spied then the bird disappears behind the reeds. The tranquility of the Gironde's diversified environments - marshes, islands, sand dunes, cliffs, sandy beaches, hills, forests, vineyards - encourage migratory birds to stop over; some also nest.
We are sailing near the right bank, between Blaye and Mortagne-sur-Gironde. Simon is again inspired: "The Estuary is bordered by a vast marshy area of 15,000 hectares, along more than 40 kilometers. In St. Ciers, it is 8 kilometers wide, can you imagine?". My friends have also taught me that along these shores, the reedbeds still provide privacy for the otter and mink, one of the most endangered mammals in France. These animals flee human presence and prefer to hunt at night so, no chance I will see one. On the other hand, I spotted a ball of fur that glides through the water and crosses a channel post-haste. "Another coypu!" Simon protested.
In former times they drained the marshes, they were considered unhealthy. They were diked to expand cultivation or even to produce some sought-after wines such as those from île Verte . More recently, since the 1980s, a galloping urbanization has taken over. Fortunately, despite the construction work, a large part of this wetland heritage still remains.
The marshes perform several ecological functions. Apart from the wildlife they support, they play a role as a physical and biological filter in improving water quality. These wetlands also provide an important buffer between the watersheds of the tributaries and the estuary itself. The waters of the Gironde enter the marshes during strong high tides. During a storm in 1999, they ignored the levees and submerged these lowlands. The sudden rise of sea level, similar to a tidal wave, destroyed fields and dwellings (they are sometimes inhabited), which remained isolated by flood waters.
Further upstream, at the level of Braud-et-Saint-Louis, the flooding almost caused a major incident. The nuclear production center of Le Blayais along the shore of the Gironde is situated as the crow flies 50km north west of Bordeaux. On 27 December 1999, the dikes that surround and protect the site were broached. Thousands of cubic meters of water invaded the place and waters rushed into the underground galleries whilst another drowned its back-up systems. In turn, the wind caused the rupture of high-voltage cables which connect it to the central network. The current could no longer escape. Urgently they halted the reactors. Fortunately, the emergency pumps worked. Had one pump failed it would have been a disaster. The storm took place on a day of medium tide, but during high water, the water level in the estuary would have been much higher. No one can rule out the possibility of another storm, a day of high tide ... Even if it's hot on the water in May, a shudder runs down my back.
At Mortagne-sur-Gironde which is off in the distance, the storm has created numerous breaches in the levees surrounding the polder once used for grain farming. It was purchased by the Coastal Conservancy in 2000 and maintained accessible to high waters, as is the case for the polder of l’Île Nouvelle acquired in 1991. The objective was to increase the efficiency and sustainability of the dams by preceding them with a salt marsh, a place where any swell might gradually attenuate. But also to recreate diked salt marshes which have largely disappeared - they are now ... dépoldériser. Wasn't it Francis Bacon who said "Nature, to be commanded, must be obeyed."?
Today these former polders guarantee the vital functions of reproduction and nurseries for fish populations. As the word "fish" escaped my thoughts, my eyes automatically return to the turbid waters of the estuary and Simon pulling up his traps. He is right, the Gironde is one of the largest European axes of migration since it is also home to all the migratory fish: sturgeon, eel, Atlantic salmon, sea trout, marine and river lamprey, twait and allis shad. Species living alternately in fresh and salt water. The estuary is a great place for passage, food, preparation and physiological growth.
The sturgeon, queen of the species in the Gironde is a relic, and Europe's most threatened fish. Once abundant in most major European rivers, it gradually started to disappear from the late 19th century. Today, there are only a few thousand individuals, all originating from the Gironde-Garonne-Dordogne basin. The last breeding date was 1994. Since 1982, the 'Sturio', so-called by scientists, is protected by law. Simon remembers, "My father fished "Créacs" on the Blaye side in the 50s, and they were large at the time of the caviar! Beautiful females - 3 to 5 meters!But I really only knew the time when we caught them young." Since 1994, no natural reproduction has occurred in the Garonne nor the Dordogne. "What a mess" - he takes up again - "and yet the estuary seemed so inexhaustible." Overfishing, yes, but also pollution and dams which degrade their habitats. They are a deadly trio well known for their part in the disappearance of aquatic fauna around the world.
I decided to cheer up my friend. "Perhaps you know there is a plan to safeguard the 'Sturio' in Europe and in France a restocking plan was launched in 2007." Simon did not respond but appears to pout. I continue unperturbed: "and thanks to the stock of spawners maintained at the research station of Saint-Seurin-sur l'Isle, researchers have developed methods of artificial reproduction from wild broodstock. L'Irstea will soon be running its sixth campaign of releasing juvenile sturgeon. They launched some fry just a few days old, nine days old I think, tens of thousands weighing 3 to 5 grams ... do you hear...? ". Of course, he does.
"Oh yeah? Other fish should thoroughly enjoy it, dion! ". Fine, I even expected his annoyance, I slip in: "Some fish tagged prior to release now grown were recaptured. That's a sign of their survival in the wild in good condition, right?".
As if by answer Simon pulls up his last trap with a dexterity which belies his age. He pulls it into the boat after blocking the bottom cable. With the trap open, an eel about 20cm long slithers out and joins the others of about the same size in the bottom of the bucket. "Look! Doesn't look so hot your natural world!" Simon stands astride the boat - "five unfortunate eels in six traps, talk about fishing!". I decide to tease him "Messire, could it be you don't know how to fish!?" Simon grabbed an old plastic yoghurt pot recovered with one of his traps from the floor of the Gironde, and with a malicious look holds it up to my face: he bursts out into laughter.
After this skirmish, and since, after all, the Gironde estuary is also an estuary viticole, we decided to drink his health. Simon slips out two glasses from his picnic basket along with a bottle of red wine from his vineyards in the Saint-Emilion appellation. Certainly this is not a grand cru, but the wine is good. It is produced by one of last professional fishermen-wine growers, still numerous in the 1960s, also endangered now. Simon is determined to dispense a little of his savoir-faire. "Now, this wine is a blend of three varieties: cabernet franc, cabernet sauvignon and merlot. And as you know, Cabernet Sauvignon is very influenced by heat? Hey ... well, with global warming, a few years from now, if my son continues, he will produce a wine only from Cabernet Sauvignon, as in California! So yes, the climate will be more important than the soil". I do not know if this prospect really delights my friend. On the other hand I know that the marriage of flavours of wine and fish has enriched the local heritage of the Gironde: lamprey à la bordelaise (lamproies à la bordelais), stewed eels (matelote d’anguille), fried eels with white wine – referring to their method of catch (pibales fricassées au vin blanc - tiny eels prepared in the crisp and crunchy 'Spanish' style ) ... my stomach gurgles - it's time to eat something. We bite hungrily on the bread and pieces of our charcuterie (grenier médocain - the local andouillette) while picking up our conversation on fish.
It's true, the eel population fished at every stage of its life is now at historically low levels. But this phenomenon is observed throughout the European Mediterranean. Simon adds: "After the virtual disappearance of sturgeon and salmon, eel numbers have also declined. This species alone contributed more than 60% of our turnover. The allis shad? A dramatic drop in stock in the Gironde and its closure by a fishing moratorium in 2008 for 5 years ... frankly, I pity the young! It's the end of artisanal fisheries ... " How can I contradict, and only the stocks of sea lamprey now appear satisfactory.
I throw a glance at the captured yellow eels. They seem lively and slip eagerly through my fingers. No ulcer or bleeding. Outwardly, nothing abnormal to report . But in 2010, eels were neither marketable nor consumable. Our basin was in the spotlight compared to other French and European sites. The incidence of polychlorinated biphenyls (or pyralenes) called PCBs were higher than normal. Prohibition orders have dropped since 2009 in various sectors and the eel, but not its fry stage, and twait shad were still affected by these restrictions in 2010 and 2011, across almost the entire river-estuarine system in the department of Gironde.
Until the late twentieth century, the Gironde was considered one of the least polluted estuaries in Europe because it possessed little industry. For several years now, recent studies have demonstrated a general deterioration in its quality. On this type of large basin, the impact from various human activities adds up quickly.
Pollution is chronic and diffuse. It is accentuated by the particular character of the estuary and the phenomenon of bioaccumulation throughout the food chain. Chronic pollution, also polymetallic (cadmium, zinc, copper, mercury) coming from old mine tailings. The most contaminated fish are those which live longest in the estuary, more than 3 years (eel, mullet and flounder). Through complex processes, the 'turbidity maximum' may also affect the behavior of these contaminants and amplify their negative influences on the health of aquatic species.
Our eyes move towards the navigation channel. Two cargo ships cross in the distance but neither of them is this huge ship that since 2004 serves to carry part of the fuselage of the Airbus A380 from St. Nazaire to Pauillac . Maritime traffic requires access to the estuary by regular dredging of the channel through the Port of Bordeaux. The Port monitors the environmental impacts of dredging for the most recent sediments are pickled, and the older sediments, the most contaminated, are brought into contact with the aquatic environment.
The water quality is also influenced by domestic and industrial discharges from large expanging cities. Along the Garonne, between Bordeaux and Toulouse, there are more than one million inhabitants. During low flow (less rainfall), the river is particularly used for pumping for irrigation of the agricultural areas. The last severe water deficits were observed in 1986, 1989/90/91, 2003 and 2006. However, in the presence of the famous 'turbidity maximum', the flow is one of the key factors of oxygen deficit. When the concentration of oxygen dissolved in water becomes too low, it can lead to critical situations for most fish. Against the backdrop of global warming of the planet, the human pressure has also resulted in an elevation of temperature to about 2°C of estuarine waters since the late 1970s. All of this will obviously affect fish distribution and species richness.
Another impact - herbicides. They have an agricultural origin but also urban. Pesticide usage in the Garonne and the Gironde were monitored. Concentrations have always been low, except during periods of habitual crop treatment in late spring and early summer. The relatively low levels used in winter results in a dilution effect and an expulsion of these molecules. I slyly slip a few words to Simon whilst draining my glass: "And, your vineyard, you treat her?". Dodging my question, Simon replies: "I read in Sud-Ouest Note 1the local newspaper for the Gironde that nitrate concentrations have increased 20% in ten years. It comes from above...” he flicked his head upwards and to the south, “the agricultural areas along the tributaries of the Dordogne and the Garonne."
Before I could answer, he added. "And Le Blayais which pumps 168 cubic meters of water per second, it has also degraded the wetland, no!? ... ". A sensitive issue since it started in 1981. The center of nuclear generation is the subject of careful monitoring. If the thermal impact of the discharge of heated water seems negligible, the mechanical drums that filter the water needed for cooling is more tangible. It induces a mortality which varies according to the fragility of the species and their stage of life. One hundred percent for gobies and young shad. "I have read that the destruction of shrimp was estimated between 40 and 50 tonnes in 1985? As much as the total production of commercial fishing at the time!" Simon starts the engine. Despite some bad faith, sometimes it is the fishermen who take time to read the scientific documents and search for more information.
We are heading home and the wind picks up. Yes, for many years, the degradation of the Gironde estuary has been denounced by interested associations, especially the fishermen, scientists and local communities. For the last ten years, there have been a number of intiatives which focus on estuarine protection, cooperation and understanding. The Joint Association for Sustainable Development of the Gironde estuary (SMIDDEST) was established in 2001 by the departments of Gironde and Charente-Maritime. In 2004, the Aquitaine and Poitou-Charentes Regions joined the Syndicat Mixte, followed by the Urban Community of Bordeaux in 2010. By 2002, a land use planning and water management system, "SAGE", was engaged for the estuary. The challenges are to improve the environment whilst preserving human activities (active tourism, energy production, fishing, commercial shipping, agriculture, forestry, urban planning...).
The Gironde estuary is vital to migrating fish. As such, it was ranked in 2006 as a special protection area within the Natura 2000 European network which combines nature conservation and socio-economic concerns. But nothing is that simple. Cases of aggregate extraction in the main channel of the estuary and at sea are regularly contested. These are threats to the benthic habitats (at the intertidal zones) for sturgeon. For ten years, scientists have been researching their nursery zones in the downstream sector of the estuary. It still remains to identify the critical habitats used by this species on arrival at the age of 8 months until they leave the estuary 7 years later. Conservation plans for sturgeon and research into their habitats in the larger arena are needed. A natural marine park in the Gironde estuary and the Pertuis Charentais are also part of the plans following a ministerial decree in 2008.
Near the dock where we land at Port Maubert, I smile at Simon reading a notice put up by the local council: "Exceptional natural site: the Gironde estuary is one of the most authentic in Europe. " It is true, and although the Gironde is touched, it is far from being dead.
References
| ↑1 | the local newspaper for the Gironde |
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