It is undeniable that the impact of tourism on primitive populations can have negative aspects. It is also certain that the complex and fragile ecology of the rainforest could be affected by poorly controlled mass tourism.

It seems to me essential to totally preserve certain zones by limiting their access to authorized scientific missions and authorities as is done for part of Southern French Guyana.
However, in spite of its faults, tourism seems to me the least destructive among "development alternatives" if it emphasizes ecological discovery rather than "pleasure" or alleged athletic activities such as boat races on large rivers or motorized treks.
What are the other alternatives? Mining activities, wood cultivation, animal husbandry and agriculture. All of them imply massive wood clearing, sometimes even total in the regions concerned as well as important contaminations, especially in the case of mining activities.
Agriculture can be the lesser evil, especially if it concerns species that are more or less compatible with the rainforest such as cacao and coffee.

Industrial or agricultural projects related to zones covered by the rainforest all speak of "rational" and "necessary" improvements. The "necessity" of such undertakings can be subject to debate… It is true that one is faced by a rapid population increase but the technologies of the present world make development without infringing upon virgin regions possible…. Amazonia's contribution to Brazil's economic activity represents only 10% of the total.
As for the use of the word "rational", it is a mark of cynicism and untruth. I think that I insisted at length on the extreme complexity of the rainforest's ecology and on its very slow regeneration. There is no "rational" development. Any development ends up necessarily in partial or total degradation.

The size of the large Amazonian rivers has favoured the explosion of biodiversity: these rivers are so large and numerous that many ecological "islands" were formed, many species having hesitated or been incapable of crossing such wide expanses of water, evolved therefore in very isolated fashion.
The clearing of a rather extended zone certainly entails the definite elimination of these endemic species.

The case of dams, for example, is tragic: I recently went on a fishing trip on the Guri dam lake in Venezuela, a dam which was at a certain time the largest in the world. Because of the extreme drought of the recent years, I was faced by a depressing spectacle of desolation. I navigated for hours on a real sea of dead trees, sinister witnesses of the forest which became drowned when the dam started its operation. The dam measures 150 km long and more than 50 km wide. How many plant, insect, batrachian and reptile species were eliminated by such a widespread destruction? Brazil and Venezuela are currently facing huge problems with their hydroelectric power stations. Could it be nature's just revenge? It must be said that large ecological projects are often perceived, if they originate from the action of foreign organization, as manifestations of insidious neo-colonialism as well as a round-about and pernicious way of limiting access to potentially enormous resources. Even harmless scientific projects can seem suspect: some scientist friends of mine who were making observations on monkeys in Southern Venezuela were expelled by the National Guard because villagers complained that it was inconceivable to spend so much time and means just studying monkeys and that surely my friends were illegally undertaking some mining activities! But they came back, the authorities having probably recognized their mistake….

As I am writing these words, the Brazilian Parliament is in the process of enacting a bill whose aim is to give permits to work in a protected area of the rainforest, on a surface equivalent to three times the area of Portugal…

I don't need to tell you hat I am crossing my fingers!!!