31. October 2019

Building with Nature

“I look at sediment management from a natural perspective. In the projects I am involved with, I look at sediment as a source to create natural values. To create salt marshes and systems that redefine sediment instead of just throwing it out into the sea and wait to see where it ends up. We can use sediment as a resource to recycle – to make something more beautiful of it.”

Martin Baptist is an engineer and marine ecologist at Wageningen Marine Research and working for EcoShape (NL). His interest in the harmonisation of human impacts with natural processes is central in one of his project which researches on the smart use of dredged sediment for the growth of salt marshes.

Salt marshes are very important ecosystems for several reasons:

  • They are breeding and resting places for birds
  • They are spawning ground for fish
  • They reduce wave impact and protect the coast against erosion
  • They trap sediment so the coast can grow
  • Salt marshes also capture CO2

But the climate changes and the rise of sea level puts salt marshes under pressure. Martin Baptist is part of a project that investigates the right conditions for salt marsh construction and the best possible ways to develop salt marshes in a natural way.

In this project, the Marconi salt marshes, the EcoShape consortium studies morphological and biological conditions in a constructed salt marsh in large-scale experimental plots. Sand was mixed with dredged sediment in various percentages and parts were sown in with Glasswort seedlings. Knowledge obtained in the project helps the development of climate adaptation measures worldwide.

Another project Baptist is involved with is the ‘Mud Motor’. A Mud Motor is a dredged sediment disposal in the form of a semi-continuous source of mud. Natural processes are allowed to disperse the sediment to nearby mudflats and salt marshes. The Mud Motor is part of the Living Lab for MUD (Multifunctional Use of Dredged sediment) by Ecoshape and its partners that carries out five pilot projects to develop knowledge about the sustainable use of sediment.

The Mud Motor project showed that the feasibility of a Mud Motor depends on an assessment of travel time for the dredger, the effectiveness on salt marsh growth, reduced dredging volumes in a port and many other practical issues.

Sediment and salt marshes

Martin Baptist joined us as a speaker at our latest workshop on Sediment Management in Ports to present his perspective on sediment. He shared his research on the beneficial use of dredged sediment to enhance salt marsh development by applying a “Mud Motor” and by constructing salt marshes.

Sediment management is a necessary part of port maintenance and development that ensures ports’ ability to support big vessels and large volumes. The use of dredging technology differs and the most sustainable solution may also differ depending on each port. However, the disposal of sediment is necessary for many ports and can cause issues. Re-using sediment for salt marsh development is a sustainable way of using existing materiale.

Martin Baptists’ research have improved our understanding on transport processes in the channel and on the mudflats and salt marshes and provides guiding principles for future application of sediment management in salt marsh development.