04 June 2021

Finding a North Welsh estuary for fieldwork

 In pre-pandemic times, we would go to South Wales each year to show the students the many faces of an estuary. We would have them survey it to check for whether it is filling up with sand or not, they measure sediment transport, they check where the boundary between salt and freshwater goes, they check for sedimentary structures, they do geophysics behind the barrier, they take a sediment core, and of course they look at microfossils. This past year, we had done it all pretty much online. I think there was a geophysics session, and there may have been some sediment sieving, but there certainly was no residential fieldtrip on the other side of the country. And this coming year we are expected to have an actual fieldwork, but this time in the north, so we won't go residential. We just think the pandemic situation won't allow it. But that did mean we needed to find a suitable estuary nearby! And in a meeting we had decided we would try it with the estuary of the River Cefni, on Anglesey. So we needed to do a bit of a recce there.

I had told Jaco I intended to go, then he had suggested we go together. That was fine with me, and on a sunny Wednesday morning we met up at a convenient parking lot. We put on our mud-resistant shoes, and off we were. We were on the marsh in no time.

It didn't look like it had anything like the beautiful vegetation zonation the Taf estuary has, but there were zones of sorts, and I took a sample in each. Most of my samples are always in the vegetated zone, where Jaco has little to do as there aren't any bedforms, but sampling doesn't take much time so soon we were on the sand flat. In theory, that is where it gets interesting for him. But there was nothing to be seen there other than worm poo and bird footsteps. That is not what floats his boat, so we kept walking. Quite far into the estuary we finally found some ripples! Of various types. It seemed enough for what he wants to do with the students.

We were done, so we walked back. We had only spent about an hour in there, but we probably gathered enough information/material will be able to now prepare our parts of the fieldtrip!

One of the vegetation zones on the saltmarsh

Jaco on the sand flat

a shell bank


No comments: