Chapter Four
The first account "vie d'un lac alpin"
4.1 This slim volume (referenced below as DRS) has an introduction, three chapters, a conclusion and a useful bibliography.
4.2 The introduction raises the alarm over the devastating impact of rampant industrialisation on the global environment. Dr. Servettaz argues passionately for the protection from pollution of scarce natural resources and habitats.
4.3 He then focuses on the specific plight of lakes threatened by a rapid increase in urbanisation and in particular Alpine Lakes such as Lake Annecy. He gives an overview of the natural life of the lake: how the lake water is replenished, the changing temperature of the lake throughout the year, and throughout its depth, the existence of different layers of water within the lake, the way water dissolves salts, the importance of oxygenation of the water, the effect of photosynthesis on the surface of the water which brings the salts and oxygen to combine to form organic material, and finally the effect of different seasons and the weather on life within the lake.
4.4 Dr. Servettaz then focuses specifically on the structure of Lake Annecy, its formation during the ice age, the rivers that flow into it, and the volume of water it contains and the "inner life" of the lake.
4.5 Only near the end of the book, on page 58, does he then comes to the heart of the story! How Lake Annecy was threatened by eutrophication and what he did to raise the alarm.
4.6 He describes how he saw the lake deteriorating while most of those around him failed to notice any problem. He describes his collaboration with local fishermen to raise the alarm with the responsible authorities, the department of construction (Roads and Bridges). And within a few pages he steps through the intervening twenty years to the completion of the building of the sewage pipe around the lake! Being the scientist he is, he then devotes several pages to scientific studies of the lake which demonstrate the beginning of its recovery from the effects of eutrophication and includes in an appendix a simplified diagram setting out the fundamental chemical interactions which take place in the lake to produce livings organisms.
4.7 He concludes with some thoughts for the future protection of the lake and a call for constant vigilance to preserve the beautiful, unpolluted character of the lake.
"Often there is nothing on the surface, all is beneath, search for it!"
Paracelsus, Swiss Doctor 1493 - 1541 (DRS 7)
4.8 Dr Servettaz launches his first account of the story of the saving of Lake Annecy with an impassioned appeal.
"At the end of the 20th century Humanity finds itself amid strange and disturbing paradoxes which at times approach absurdity. Consider! some people are dying of hunger, while others demolish food to excess, at the same time advanced industrial civilization invests enormous financial resources into fundamental medical research whilst at the same time discharging without scruple or reservation toxic waste into the immediate environment of its citizens"
4.9 Chapter One, subtitled "Getting to know the intimate life of Alpine lakes", gets to the heart of the Doctor's message. An Alpine lake is a highly complex, delicate environment, constantly changing in response to a variety of internal and external factors. Tourist sites and marketing brochures generate images galore of Annecy's beautiful blue lake. Here the Doctor describes the living world beneath the surface - what Mobious named in 1877 - the "biosphere".
4.10 He describes the interaction between oxygen, carbon, minerals and sunlight which has produced a vast range of microscopic life, first vegetable - phytoplankton - then animal - zooplankton. He explains the physics of movements within the body of the water, as vertical currents, driven by temperature and density differences as well as by the wind, which play an essential role in circulating and refreshing the various life forms within the lake. He describes the surprisingly distinct layers of water within the lake, defined by their differences in temperature, density and their content of life, minerals and dissolved salts and gases.
4.11 A particularly fascinating aspect of this constant movement, is the annual "brassage" where the entire body of water turns over. Most of the year the upper layers of water are, unsurprisingly, warmer than that at the bottom of the lake, which keeps a constant 4º C throughout the year. The bottom layer keeps a constant temperature because of one of its many remarkable peculiarities: water has its greatest density at 4º C. So in winter, as the temperature of the whole lake drops towards 4º C, the column of water becomes unstable and eventually overturns, circulating and refreshing the biological contents of the lake.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
"This phenomenon is so recent that one single generation may see changes take place that would have taken millenia without the presence of mankind.
The accelerated death of these lakes is a calamity directly linked to the repercussions of increased urbanisation." (DRS 45)
4.12 This profound circulation brings to the surface dead and decayed matter that had fallen to the bottom throughout the year and carries fresher oxygenated water to the depths of the lake. This process of "refreshing" is crucial to the health of the lake but results from an entirely serendipitous change in temperature from summer to winter specific to its alpine setting.
4.13 Ominously this is precisely one of the effects that is at risk from global warming should the upper layers of water remain above 4º C during warm winters.
4.14 Next is a discussion of the chemistry of the water: the importance of dissolved salts and oxygen in the lake, and the fundamental chemical reactions which produce phytoplankton, processes that go back to the spreading of life in the oceans as least as long as 3.8 billion years ago.
4.15 This combination of physics and chemistry produces a constantly circulating solution of microscopic life which has achieved a delicate equilibrium over many thousands of years.
4.16 But this delicate and complex balance of nature is threatened by the waste discharged thoughtlessly into the lake by surrounding urban communities.
4.17 This sewage pollutes the lake not because it is "dirty" but because it is a fertiliser - it promotes growth. It causes excessive growth among the phytoplankton in the lake from which some species benefit at the expense of all the others. They grow in huge volumes and cover the surface of the lake with their green slime, which first kills off all other life in the lake by blocking the sunlight and extracting oxygen, and then die themselves producing a vile smelling putrifaction.
4.18 This is what they mean when they talk of a lake dying.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake
4.19 Dr Servettaz now turns to the history of Lake Annecy, and how it was first inhabited 6000 years ago by fishermen who built wooden huts on stilts at the shoreline of the lake as it rose and fell with the seasons, and how it provided a living environment for these first dwellers.
"Lakes are not a simple accumulation of cubic metres of water waiting to be exploited, ... but should be seen above all as a unique living environment, a single organism rich in inter-connected chains of animal and vegetable life." (DRS 30)
"An opportunity is a precise point in time when one should do something!"
Plato (DRS 61)
4.20 This chapter subtitled "A propos of Lake Annecy" focuses on a detailed description of Lake Annecy, its dimensions and volume and from which rivers it draws its water and to which its waters flow.
4.21 And finally, at last!, on page 59 of his 81 pages, the good Doctor comes to the heart of our story - what exactly happened at Lake Annecy in those years immediately following the liberation from German occupation? When exactly was Plato's precise point in time and what actions where taken and by whom! This is the story!
4.22 On page 60 we read: "It was indeed difficult to make the public in general aware of the real conditions of lake life, its particular characteristics. Everyone continued more or less out of habit of thought to believe that the Lake had unlimited powers of self cleaning." Nevertheless, thanks to his efforts of persuasion the wider community slowly began to understand that something had to be done, and so followed the remarkable story of the construction, over twenty years and at a cost enormous for the time and the size of the local community, a vast waste water pipeline surrounding the entire lake.
4.23 Dr Servettaz concludes with his hopes and fears for the lake in future generations.
The Story
Chapter One. From the Times, 1977, Article by Alan McGregor. The only account of the story published in English
Chapter Two. From French Journal Clés, by Patrice van Eersel and Martine Castello. Update to the story, published July 2011.
Chapter Three. Dr Paul Louis Servettaz publishes three versions of his account.
Chapter Four. La Vie d'un lac alpin The first account of the story, 75 pages by Dr Paul Louis Servettaz published in 1971
Chapter Five: L'eau, la vie d'un lac alpin Updated version of the above with 280 pages, published in 1977, reprinted in 1991
Chapter Six: Water, the economic life of an alpine lake