It is poetically nicknamed the “ hairy ». The image is telling: it designates the myriad of small streams, brooks and streams which meander, shaggy, upstream of a watershed before converging towards the larger rivers. Behind the poetry, however, lies a worrying reality: the thousands of kilometers of rural waterways are in an alarming ecological situation which continues to deteriorate.
This is what a report from the WWF (World Wide Fund for Nature), published on May 22 and which aims to draw up a “ inventory of wildlife in French waters ». Inspired by the index “ living planet » made for the WWF on a global scale to quantify the state of biodiversity, the French branch of theNGO developed a “ living rivers index » in order to measure the evolution of the biodiversity of waterways in mainland France.
This index currently only measures the evolution of bird and fish populations, with work on insects, crustaceans and other species still in progress. It aggregates existing data over the last 20 years, provided by the French Biodiversity Office, Water Agencies and the Temporal Monitoring of Common Birds program in particular. Result: since 2001, the index indicates a slight decline, of around 0.4 % of river biodiversity.
Sanitation of rivers, degradation of streams
A quasi-stability which turns out to be falsely reassuring. “ The figure actually hides very contrasting situationsexplains Yann Laurans, program director of the WWF France. Because public sanitation policies have greatly improved the state of France’s major rivers. On the Seine, downstream of the Pont de l’Alma, in Paris, there are six times more species today than in the 1960s. »
This improvement masks “ the collapse » of the quality of watercourses in rural areas, denounces the WWF. Example of this discrepancy: the evolution of populations “ river birds » (those moving within 100 meters of a watercourse) indicates a drop of 3.5 % since 2001. But by focusing on these birds in agricultural environments, the drop triples, to – 10.55 %.
© Stéphane Jungers / Reporterre
To make this collapse even more concrete, theNGO insisted on the catastrophic situation of two common species, emblematic of our rivers. Firstly, the great crested grebe, which is distinguished from ducks by its ruffled crest, saw its numbers drop by 91.5 % At XXIᵉ century. River trout, for its part, suffered a decline of almost 44 % in our rivers in two decades.
The difficulties of these two species reveal the state of the environment: grebes like stagnant water and gently sloping banks. They could have borne the brunt of successive droughts as well as the development of human activities on their territory (fishing, swimming, nautical activities), suggests the WWF. The trout is dependent on small fresh watercourses, which have been “ rectified »deepened and widened, reducing the habitats available for the species.
More generally, the report points to two main types of river degradation which harm biodiversity. Physical degradation on the one hand (obstacles to flow such as dams, morphological degradation such as dredging, channeling or rectification of watercourses, or even excessive withdrawals, for irrigation for example) and chemical degradation on the other hand, that is to say mainly linked to agriculture (pesticides, phosphates, nitrates) as well as industrial micropollutants.
© Stéphane Jungers / Reporterre
Pesticides which pollute waterways constitute a particularly significant point of tension. We still use as much today as in 2009, points outNGOfar from the reduction objective of 50 % set for a decade by the Grenelle Environment Forum. The presentation, at the beginning of May, of the government’s new Ecophyto plan does not suggest any improvement in this area since it introduces a change in indicator, highly contested for its propensity to artificially reduce the use of pesticides.
Agricultural policy, which encourages intensification, is also at the origin of the ever more massive uprooting of hedges in rural areas, which notably includes hedges bordering watercourses, which are called riparian forests and which play a crucial role for the biodiversity of these environments. However, according to the report, the removal of hedges went from 10,400 km less per year, between 2006 and 2014, to 23,500 km per year on average between 2017 and 2021. Land drainage has also been to the detriment wetlands, half of which disappeared between 1960 and 1990, recalls the report.
All this contributes to the fact that the surface water masses judged in “ good condition » only increased from 41.4 % of waters at 43.1 %, from 2009 to 2019 in France. Even though the French objective, inspired by the European framework directive on water, was to reach 100 % in good condition in… 2015. “ The objective was pushed back to 2021 then a new exemption was made for 2027 but we will not be there. We need to seriously question our water policy »insists Yann Laurans.
THE WWF points out the gap between the current situation and the considerable sums of public money swallowed up over the past 20 years for water policy, which it estimates at 500 billion euros. “ A considerable effort, which we welcome, but which is not enough. »
Example of the shortcomings of public authorities: the objective taken during the Water Conference to restore 25,000 km of watercourses remained without follow-up, deplores the association. Even though the objective was quite modest, compared to the nearly 430,000 km of rivers officially recorded in France. The largest network of waterways in Europe.
The essential agricultural transition
“ We empty the ocean with a teaspoon », sighs Yann Laurans. In addition to reaffirming, at a minimum, this objective of large-scale restoration of watercourses, the WWF pleads for a rethinking of water taxation, to truly apply the principle “ polluter pays ». L’NGO also calls for a systematization of the protection of wetlands and a national plan for the protection and restoration of permanent meadows, which help to slow down and clean up the water cycle.
But most of the effort will necessarily go through agriculture. To help replant hedges (and no longer destroy them), reduce the use of pesticides, protect meadows, wetlands and ponds, we need an ambitious trajectory for deploying Payments for Environmental Services, believes the WWF.
Without forgetting the financial windfall, and the massive lever for change in practice, that constitutes the money from the European Common Agricultural Policy: “ It is appropriate to better allocate the more than 9 billion euros which are allocated each year to the 400,000 beneficiaries of the CAP »by further supporting organic farming and virtuous practices, underlines the report.
France, largely autonomous in its way of using European money from CAP, is not currently taking the path of a radical ecological bifurcation. The agricultural orientation law, currently being debated in the National Assembly, is of great concern to environmental associations. Under cover “ simplification » administrative for farmers, the bill reduces the legal risks in the event of illegal hedge trimming and is accused of facilitating their uprooting as well as significantly limiting the possibilities of appeal against megabasin projects. So many contradictory initiatives with the idea of preserving our “ living rivers ».
