KNAW Fonds Ecologie - How trophic transfer efficiency varies among habitats with different primary producers in ecological restoration project Marker Wadden

The Marker Wadden is a large ecological restoration project to restore the productivity of the food web in lake Markermeer. The Marker Wadden is a group of 5 newly built islands, which were built in 2016/2017, a project initiated and guided by Natuurmonumenten. Over the last decades the number of fish and fish eating birds in the lake have steeply declined and the lake has been very turbid through suspended sediment from the lake bottom. The Marker Wadden project aims to reverse this trend by providing sheltered sites where the suspended sediment can settle, resulting in enhanced light availability for different primary producers, such as phytoplankton, benthic algae and macrophytes, as well providing habitats for their colonisation that can alter the food web structure from the base. For example, if phytoplankton growth is stimulated, zooplankton may have more food to feed on, then these will be food for fish and potentially increase the abundance of fish eating birds, which depends on the trophic transfer efficiency, i.e. zooplankton-to-phytoplankton biomass ratio. However, how the trophic transfer efficiency varied among habitats with different primary producers is poorly understood while it is essential for the restoration of the lake food web. Furthermore, it is unclear how benthic ecosystem processes (periphyton production and litter decomposition) differ among habitats with different primary producers. I will study how trophic transfer efficiency varies among habitats with different primary producers in the Marker Wadden area. The proposed project here is a field campaign in 2020 that is part of my PhD thesis work.