Have you ever walked along a windy beach and noticed shells sitting atop small peaks of sand, like a miniature mountain range? Does a shell “protect” the sand underneath, or does the sand pile up behind it? Does the shell actually cause more erosion around it? How does a shell affect the way sand moves along beaches? What happens when you have millions of shells along a beach? Does that affect the way the beach as a whole erodes? Now what about the parts of a beach that we can’t see, below the water?
These might seem like the thoughts of an idle beachgoer, but are actually essential to helping us understand how to sustainably protect our coasts. As part of the TRAILS project, Tjitske Kooistra is investigating how sand nourishments influence sensitive ecosystems on the Dutch coast. In order to do that, we need to understand how shells and sand interact at the bottom of the sea, since there are many locations along the Dutch coast where shells make up a significant portion of the beach material. This is really difficult to understand in the field, so to figure this out in a more controlled setting, Tjitske planned a series of lab experiments and we recruited Steven Haarbosch to carry them out.
After months of hard work shovelling sand and crunching numbers, Steven successfully defended his thesis, “The influence of bivalve shells of different shapes and sizes on current-driven sediment transport“! He conducted excellent, tremendously useful research, and I am really proud of what he accomplished.
Continue reading Of Shells & Sand
Coastally Curious 