Biodiverse and Climate-Resilient Lakes: KlimBioS

Panoramic view on Lake Lucerne (Adobe Stock)

Lakes are an important part of Switzerland’s cultural and natural heritage, as well as major biodiversity hotspots. Federal law requires lakes to be preserved as near-natural habitats, which is why numerous measures have been implemented to improve their condition. Nevertheless, almost 40% of Switzerland’s large lakes still do not meet the legal requirements, and many shoreline areas remain in poor morphological condition. Additional pressures from climate change and energy production, as well as invasive species such as the quagga mussel, pose further threats to these ecosystems.

At the federal level, the Waters Protection Act (WPA) and the Waters Protection Ordinance (WPO) define the objectives for preserving lakes as habitats for near-natural communities of flora and fauna. They specify target values for water-quality parameters, including oxygen concentrations in the water column and the level of primary production (formation of biomass).

Since the peak of lake eutrophication (excessive nutrient loads) in the 1970s, numerous measures have been implemented to improve water quality. In many lakes, the resulting reduction in phosphate loads has led to re-oligotrophication (reduction in nutrient levels) and thus improved water quality.

Nevertheless, almost 40% of Switzerland’s large lakes still do not fully meet the legal requirement of at least 4 mg/L of oxygen and/or the targets for primary production and associated nutrient levels or only do so thanks to artificial aeration. For another 15% of the lakes, it remains unclear whether the low oxygen concentrations reflect natural conditions.

Moreover, over half of the shorelines of larger lakes are built up and in poor morphological condition.

To ensure that Swiss lakes remain biodiverse and resilient in the future, lake management must be adapted to emerging challenges. In this context, the joint research programme KlimBioS (Fig. 1), led by the Water Division of the Swiss Federal Office for the Environment (FOEN) and Eawag, has set the following objectives:

Status description: Assessing the current state of Switzerland’s 25 largest lakes, as well as the most important types of small lakes.
Action recommendations: Developing scientifically supported and implementation-oriented recommendations for biodiverse and climate-resilient lakes across four thematic areas:
- Water quality
- Biodiversity monitoring and lake status assessment
- Revitalisation of lake shorelines
- Sustainable fisheries

Within the framework of KlimBioS numerous projects and activities are being carried out. These bring together existing knowledge, generate new scientific evidence and promote exchange between science and practice.

KlimBioS is part of the second phase of the Swiss Biodiversity Strategy and Action Plan, Measure 2: “Biodiverse and resilient lakes under climate change” and is being conducted in close cooperation with the Conference of Environmental Agencies (KVU), the cantons, and other stakeholders involved in lake management.

Figure 1: Overview of the key thematic areas of the KlimBioS programme. (Pictures: Adobe Stock, Aquascope Eawag, Oliver Selz BAFU, Jan Ryser BAFU)

KlimBioS places great emphasis on continuous exchange with practitioners in order to define practice-relevant priorities and develop effective implementation strategies.

The programme builds on the expertise of the Eawag lake research community, other Swiss research institutions, cantonal and federal authorities, and other stakeholders involved in lake management and conservation. These include:

The knowledge gained from ongoing and completed projects such as:
The knowledge and experience of cantonal specialist
The experience of international lake commissions: CIPEL, CIPAIS and IGKB
International research and ecosystem management efforts — within the European Union and beyond
Eawag’s Lake Competence Cluster

Steering

BAFU: P. Eschmann, C. Leu
Eawag: C. Stamm, S. Hoffmann
Cantons: C. Minkowski (BE), S. Haertel-Borer (SG), N. Solcà (TI), D. Thiel (TG)

Lead

BAFU: B. Lundsgaard-Hansen, C. Dönz
Eawag: A. Narwani, M. Schmid
Practitioner Advisory Board: One to two (senior) representatives from each of the four areas

Implementation & Advisory Support

Program coordination & Integration
Lead: D. Knapp (Eawag)

Advisory Board Water Quality & Monitoring
Lead: Y. Schindler und B. Lundsgaard-Hansen (BAFU)
Combined with the advisory board NFP 82
Cantonal and scientific experts

Advisory Board Fisheries
Lead: C. Dönz (BAFU)
Cantonal and scientific experts

Advisory Board Revitalisation
Lead: G. Thomas (BAFU)
Cantonal and scientific experts