When it comes to nature and species conservation, the focus is usually on land and ocean habitats - as is the case at the United Nations Biodiversity Summit currently taking place in Montreal. But one important ecosystem type is in danger of being forgotten, scientists are now warning: The importance of inland waters such as lakes, streams, rivers or wetlands for global biodiversity has been underestimated so far.
Springs, streams, rivers, lakes, wetlands and groundwater: all this and more is part of the so-called inland waters. When talking about measures to protect the planet, however, inland waters have often simply been counted as land areas. Scientists from the Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) find that this does not do justice to their importance for the climate and biodiversity. In a statement together with international freshwater experts, they demand that inland waters should not be forgotten in the negotiations at the UN biodiversity summit currently taking place in Montreal.
"The great relevance of inland waters is still being overlooked in international biodiversity policy," criticizes IGB researcher Sonja Jähnig. They are a source of drinking water and a living space, which makes them “the basis of life for nature and thus also for us humans”.
Danger from climate change and humans
But inland waters, like other ecosystems, are in danger. The habitats and biodiversity of inland waters are shrinking dramatically, as the scientists report. This also applies to microorganisms living in the water, such as fungi and bacteria. They "form the basis of every food web and make a significant contribution to the functioning of an ecosystem," explains Jähnig's colleague Hans-Peter Grossart. One of the reasons for the decline in biodiversity in rivers, lakes and the like is climate change. It hits inland waters particularly hard because they warm up much faster than the atmosphere or even the oceans. If the water is too warm, toxic algae blooms have an easy time. They deprive lakes and rivers of oxygen, eventually suffocating fish and other aquatic life.
But the fact that small and large freshwater animals are increasingly fighting for their lives is not solely the fault of climate change. According to the biologists, people who poison water bodies with pollutants, build them up, divert them and dam them up also contribute to the fact that inland waterways are getting worse and worse. “Millions of dams and other transverse structures encourage the mass development of algae in rivers and prevent fish from seeking cool refuges during hot periods. Hydroelectric power plants contribute less to mitigating climate change than expected, because reservoirs themselves emit large amounts of greenhouse gases, especially in the tropics and subtropics,” explains Martin Pusch, also from IGB.
Equivalence with sea and land demanded
But although inland waters are so important for us humans, politicians do not take the problems of this type of ecosystem seriously enough, criticize the biologists at the Leibniz Institute for Freshwater Ecology and Inland Fisheries. This can already be seen from the fact that inland waters are not treated as a separate category. So far, on the political stage, they have been assigned either to land areas, because they are embedded in them, or to oceans, because they are also aquatic. Jähnig and her colleagues, on the other hand, are calling for inland waters to be treated as a separate category in the future - on an equal footing with land and sea: "Inland waters and their biodiversity should be established alongside terrestrial and marine ecosystems as an equally important, third ecological area in political and social frameworks and strategies. "
As such, inland waters should also be considered at the biodiversity summit in Montreal. The freshwater biologists hope that the negotiations there will lead to specific protection goals for inland waters. For example: promote free-flowing rivers and large-scale renaturation or add beneficial microorganisms to the list of species worthy of protection. "Freshwater ecosystems must no longer be just a sideshow, because they can only fulfill their diverse functions as a habitat and key resource for humans and nature if they are consistently protected, sustainably managed and ecologically improved again," summarizes Jähnig.
Source: Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB)