FutureLakes: Ecological restoration of European lakes
Freshwater lakes are of great importance for the supply of drinking water and food for both people and nature. However, in many parts of the world, the functioning of these freshwater lakes is under pressure due to human activity. Examples include nutrient overload, water scarcity, or an increase in substances that are toxic to aquatic life. To improve the quality of freshwater lakes, many restoration measures have been taken over the past few decades. In this project, we are investigating how effective these measures have been.
In the FutureLakes project, we are investigating the restoration measures taken at six demonstration sites across Europe. We are examining both innovative solutions and past results achieved through nature-based, circular and biodiversity measures. In addition to ecosystem restoration itself, we are also investigating how policy, management and the financing of measures can contribute to the success of a given initiative. Finally, we are bringing together all the knowledge we have gained in a Knowledge Hub and a Blueprint for drawing up a lake restoration plan, so that others can also make use of these insights.
The six demonstration sites serving as sources of information for the research are: Lake Karla (Greece), the Kartuzy Lakes (Poland), Lake Vesijärvi (Finland), Lake Vansjø (Norway), Loch Leven (Scotland), and the IJsselmeer region (Netherlands, see also ‘About the IJsselmeer region’). Of these six lakes, four already have a long history of restoration measures, particularly in the area of combating eutrophication, whilst restoration measures have only relatively recently been initiated at two locations (Lake Karla and the Kartuzy Lakes).
In addition to these six demonstration sites, knowledge is also being gathered on the impact of innovative measures at 10 pilot sites.
Within the FutureLakes project, Deltares has three main tasks:
- Investigating how resilient governance can contribute to the success of lake restoration;
- Supporting plans to optimise restoration packages for six European lakes;
- Compiling the Blueprint
In addition, Deltares serves as a hub for research into and knowledge sharing about the IJsselmeer region.
In this project, Deltares is collaborating with nine partners.
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About the IJsselmeer region
The IJsselmeer and Markermeer together form a unique freshwater area in the Netherlands. The lakes were created by the construction of the Afsluitdijk (1932) and the Houtribdijk (1976) and have since played a vital role in the Netherlands’ flood defences, freshwater supply and natural environment.
The construction of dykes in the area improved the protection of the hinterland against flooding, but also had far-reaching ecological consequences. For example, due to the diking of virtually all the shores of the IJsselmeer and Markermeer, there are now few gradual transitions between land and water. Yet it is precisely these ‘soft’ edges (ecological gradients) that are essential for making and keeping the ecosystem resilient. Furthermore, partly due to the reduced connection with the sea combined with a high inflow of nutrients from the River IJssel, the water became too rich in nutrients, which in turn caused significant algal blooms. The lakes also became overfished.
To address these ecological challenges, various nature restoration measures have been implemented in the area over the past decades. For instance, nutrient concentrations were reduced through the development of phosphate-free detergents and the construction of sewage treatment plants; fish stocks were improved through fishing restrictions; and some of the soft transitions were compensated for by creating nature islands.
Within the FutureLakes project, we are mapping out which measures have been taken in recent decades and what their effects have been on the Markermeer and the IJsselmeer. In particular, we are examining the impact of the Marker Wadden nature restoration measure, a group of artificially constructed nature islands in the Markermeer. Thanks to the KIMA and KIMA 2.0 research programmes, much is already known about this group of islands, which provides valuable insight into the effects that this type of nature restoration measure can have.
