Threatened water habitats
Switzerland is part of the four largest river catchment areas in Europe, making it a European hotspot for fish diversity. In particular, our country is home to a high density of endemic species that do not occur anywhere else. But this diversity is threatened. Two thirds of all Swiss fish species are on the Red List; among whitefish alone, nine species that were only found here are already extinct.
However, the problem does not only affect Switzerland: one third of the world’s freshwater animal species are threatened with extinction. The monitored freshwater populations have declined by 83 percent since 1970, meaning that biodiversity in freshwater is being lost much faster than on land.
Many amphibians and insects that live in and around bodies of water are also highly endangered or are on the brink of extinction. In addition, many species and their endangered status are not even known, and biodiversity in groundwater, for example, has hardly been researched. The urgency to act is often underestimated.
Utilisation of nature endangers biodiversity
The reason for the loss of biodiversity is that, for a long time, the utilisation of natural ecosystems was not sustainable. Many bodies of water were obstructed and straightened, drained and fragmented, impaired by electricity production and polluted by contaminants and fertilisers. Not all species can cope with these new living conditions. This is how biodiversity is lost – at the level of habitats, species and their genes.
This topic has been on Eawag’s agenda for decades. Researchers in Switzerland and abroad are focusing on the questions of how and where biodiversity in aquatic habitats is changing and how it can be protected. After all, the preservation of biodiversity is also fundamental for the survival of humanity. Intact bodies of water – whether rivers, lakes or groundwater – are central to our health and well-being. They offer protection against natural hazards and provide food, clean air and drinking water. They are also important resources on which economic sectors such as agriculture and food production depend.
From knowledge to implementation
With its work, Eawag has made a decisive contribution to achieving a great deal for biodiversity in recent years. Water pollution from nutrients – one of the main causes of biodiversity loss – has decreased significantly in Switzerland, and the restoration of numerous Swiss lakes has improved the quality of habitats for many living organisms. Eawag researchers have also played a key role in the development of methods for biological and chemical water assessment. They have contributed to the inclusion of substance-specific environmental quality criteria in the Water Protection Ordinance in the area of plant protection products, which has paved the way for a more precise assessment of water quality and thus more targeted measures. Thanks to a measuring device developed at Eawag, pollutants in water bodies can be measured automatically in the field over a period of weeks and tracked in real time on a smartphone without having to be present on site.
In addition, Eawag has laid the necessary foundation to enshrine the elimination of micropollutants in law with an additional purification stage in wastewater treatment plants. And together with the three research institutes of the ETH Domain and the Federal Office of the Environment, Eawag researchers have developed solutions for restoring sediment dynamics and habitat connectivity. This allows flood protection and revitalisation measures to be coordinated.
Mastering new challenges
Nonetheless, the challenges remain. Diffuse inputs from agriculture, particularly nitrogen, but also phosphorus and pesticides, have not yet been sufficiently reduced. Moreover, water bodies are coming under increased pressure due to the effects of climate change or the introduction of invasive species and are being contaminated by micropollutants. Eawag’s commitment and expertise are therefore still urgently needed. In order to conserve, connect, restore and sustainably utilise ecosystems on a large scale, Eawag researchers work together with the relevant communal, cantonal and federal authorities as well as with experts from the field, for example from the energy sector. They are often leaders in the development of new methods and approaches. Biodiversity is increasingly being analysed using modern methods such as environmental DNA and remote sensing, supported by artificial intelligence. The findings ultimately flow into numerous practical applications and laws.
