Water Management: 3 minutes to understand aquatic environments and biodiversity
Aquatic environments and the biodiversity they harbour form a vital balance, which is now under threat from climate change and human activities. As part of its series ‘Water Management: 3 minutes to understand’, the International Office for Water sheds light on this often-overlooked interdependence in a new video. Find out how nature and living organisms interact, and why preserving them is our greatest asset in tackling the water crises of the future.
Biodiversity & Aquatic Environments
Understanding water issues through OiEau
To mark its 35th anniversary, the International Office for Water has launched the video series ‘Water Management: 3 Minutes to Understand’. This programme aims to raise awareness amongst a wide audience — from professionals to the general public — of the major challenges facing water resources in a context characterised by climate change and increasing environmental pressures.
The first episode is devoted to Integrated Water Resources Management (IWRM), a systemic approach promoted by the OiEau for over three decades. This model seeks to reconcile the needs of human use with the essential preservation of ecosystems, by providing practical support to states and river basin organisations in its implementation.
The second episode, meanwhile, deals with drinking water and sanitation. These two issues, which are fundamental to public health, have been recognised as human rights by the United Nations since 2010 and form the core of Sustainable Development Goal 6.
Finally, the third chapter examines the natural water cycle, which has been disrupted by the combined effects of global warming and human pressures. This section highlights the strategic contribution of Nature-based Solutions (NbS). By focusing on the restoration of ecosystems, soils and wetlands, these approaches strengthen the resilience of regions, improve the quality of aquatic environments and enable the sustainable restoration of hydrological balances.
Understanding the distinction between aquatic biodiversity and aquatic environments
There is often confusion between aquatic biodiversity and aquatic environments in public debate. However, the distinction between these two concepts is fundamental.
- Aquatic environments: These are the physical spaces (rivers, lakes, wetlands, estuaries, groundwater, coastlines and oceans) that constitute the natural habitat of species. When they are in good condition, they are home to a wealth of biodiversity and play a vital role for the planet, particularly in regulating water and the climate.
- Aquatic biodiversity: This refers to all living organisms (fish, amphibians, aquatic plants, waterbirds) and the ecosystems found within these environments.
A vital interdependence: living organisms serving the environment
Habitat and living organisms work in synergy: the better the environment is preserved, the more biodiversity flourishes, and the more this biodiversity, in turn, protects the environment.
The species present provide essential ecosystem services: they naturally filter water, recycle organic matter, play an active role in food chains, and stabilise riverbanks and riverbeds through processes similar to those of bioengineering.
Even more crucially in the current climate context, this biodiversity enhances the resilience of regions in the face of extreme events, whether through the mitigation of flooding by wetlands or by maintaining water levels during periods of drought.
This process of natural purification and climate regulation is the cornerstone of our water security.
Growing human-induced threats and their consequences
The recent WWF ‘Living Planet’ report (2024) is unequivocal: within five years, without a radical shift towards a sustainable development model, the collapse of the climate and nature will trigger a chain reaction that will be impossible to stop.
Even today, habitats and endemic species are threatened by a multitude of human-induced factors:
- Water pollution: Agricultural (pesticides, nitrates), industrial and domestic (plastics, pharmaceutical residues) discharges are degrading water quality, leading to the eutrophication of ecosystems and poisoning flora and fauna.
- Habitat destruction and fragmentation: River engineering (dams, dykes) disrupts ecological continuity, preventing species migration and sediment transport, and degrading the diversity of microhabitats necessary for biodiversity.
- Climate change and overexploitation: The increasing frequency of extreme weather events and rising water temperatures exacerbate the severity of hydrological crises (prolonged droughts, violent floods) and degrade habitats, whilst excessive water abstraction and invasive alien species jeopardise the survival of local flora and fauna.
This degradation has a cascade of consequences: the disruption of ecological connectivity, the extinction of species, and the deterioration of water quality, for example, all of which have a direct impact on our health, our economy and our quality of life.
Aquatic environments and biodiversity: OiEau’s comprehensive response to climate challenges
Faced with mounting environmental and climatic pressures that are undermining aquatic ecosystems, the conservation of water resources requires a comprehensive and coordinated response. Halting the decline in aquatic biodiversity is no longer merely a matter of environmental protection, but constitutes a strategic challenge for the resilience of our regions.
To address these major challenges, concrete courses of action exist, such as sustainable land-use planning and the restoration of natural dynamics. By mobilising all stakeholders at the catchment level, these solutions aim to reconcile the preservation of ecosystems with future water security.
To halt this decline, for over 35 years the International Office for Water has been implementing strategic, operational and technical projects with a wide range of public and private stakeholders, from the local to the cross-border level.
Because there can be no effective protection without a shared understanding of the issues at stake, the centralisation and dissemination of knowledge form one of the pillars of the OiEau’s work, for example through the EMWIS network. Together with Spain and Italy, the Office spearheaded the creation of this Euro-Mediterranean Information System on Water Expertise, which has become the main platform for knowledge exchange within the region. OiEau provides ongoing technical and policy support through the management of its unit, as well as by facilitating institutional exchanges between the member countries of the Union for the Mediterranean.
Furthermore, since 2014, OiEau has been publishing the Aquatic Biodiversity Newsletter with financial support from the French Biodiversity Agency. This ongoing information service compiles news, innovations and regulations relating to aquatic biodiversity in France and internationally.
This dissemination of knowledge is accompanied by a commitment toembedding best practices within the realities of local areas, making the sharing of lessons learnt and the creation of synergies between stakeholders a necessity. It is as part of this initiative that OiEau plays an active role in running the Wetlands Resource Centre, through the implementation of the CESP strategy (Communication, Education, Awareness-raising and Participation) as part of the National Wetlands Plan. In practical terms, our teams organise awareness-raising events, lead technical meetings, carry out specialist studies and help to coordinate the network of managers.
Protecting and restoring aquatic environments also requires genuine technical expertise in the field, which OiEau delivers by placing continuing professional development at the heart of its support. Through its Training Centre, it offers educational programmes specifically tailored to the new challenges of biodiversity conservation. Whether it involves restoring a river’s hydromorphology, constructing structures to re-establish ecological continuity, ensuring environmentally sensitive maintenance of watercourses, or designing Nature-based Solutions (NbS), these training programmes aim to impart highly specialised expertise, combining theoretical input with practical scenarios within its 45,000 m² of training facilities.
In order to translate the challenges of ecosystem conservation into concrete actions on the ground, OiEau provides technical and institutional support to local authorities, water agencies and state bodies, both in France and internationally. This support is specifically aimed at placing the protection of aquatic environments and their biodiversity at the very heart of planning documents, such as Water Development and Management Schemes (SAGE) or cross-border river basin plans. In practical terms, OiEau contributes its expertise to the design and evaluation of ecological restoration projects: this includes, for example, renaturalising watercourses to restore fish migration routes, or rehabilitating wetlands that are essential for the reproduction of local wildlife. Through its involvement in major European and international cooperation programmes, the Office helps local authorities to design and implement Nature-based Solutions (NbS). These strategic actions help to recreate rich and resilient habitats, capable both of supporting abundant biodiversity and providing vital ecosystem services in the face of climate-related hazards, such as flood mitigation and maintaining water flows during periods of drought.
Through this multidisciplinary approach, OiEau achieves a balance between human development and the protection of nature. Investing in aquatic environments is an essential commitment to the future for the security of our societies.
FaQ
Biodiversity and aquatic environments: find out more
Aquatic environments refer to the physical spaces (rivers, lakes, wetlands, groundwater, estuaries) that constitute the natural habitat of species and provide them with the conditions essential for life, such as water, oxygen and temperature regulation. Aquatic biodiversity encompasses all living organisms (fish, amphibians, insects, plants, bacteria, plankton) living within these habitats. Their relationship is based on a vital interdependence: whilst the environment supports life, biodiversity in turn maintains the environment’s good ecological status by filtering water, recycling organic matter, stabilising riverbanks and strengthening the resilience of local areas to floods and droughts.
Aquatic environments and biodiversity are under the cumulative pressure of several major factors:
- Intensive agriculture: a major cause of eutrophication linked to nitrate and pesticide inputs.
- Multiple forms of pollution: chemical, industrial, plastic and microplastic discharges that degrade water quality.
- Land-use changes and fragmentation: the urbanisation of riverbanks, soil sealing and the presence of hydraulic structures that disrupt ecological continuity.
- Climate change and overexploitation: worsening droughts and excessive water abstraction threatening habitats and endemic species.
This degradation is leading to a massive decline in freshwater species, a deterioration in water quality and a reduction in the ecosystem services essential to human health and the economy.
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