Everyone watched intently as we submerged the constructed saltmarsh for the first time… It was amazing to see the water trickling onto the marsh ‘platform’ from both ends and there were several remarks along the lines of “This looks just like a real marsh surface when the tide comes in!”. It was critical to regulate the water inflow carefully, so as to reduce any potential difference in the water level at either end of the marsh that could have resulted in damaging currents and it worked! Slowly but surely the water made its way onto the marsh and along the gravel ‘fill’ in the gap at the very edge on one side of the flume. A simple process, but one that we have now been waiting for with a lot of anticipation for a very long time!
What we were not sure about was how the air trapped inside the sand base and the soil surface would eventually make its way to the surface… but it was soon clear that there were enough small holes and root channels in the clay to allow a steady escaping of air. Some of the bubbling action became fierce enough to start resembling a whirlpool-type jet, getting us very worried that the force of the bubbles could break up the overlying clay. But the bubbling eventually subsided, the marsh stayed put, but….
…as the flume starts to fill, up goes the cry ‘mouse!’ And there it is, frantically swimming across the saltmarsh section. The ‘basket’ is quickly deployed and the little ball of fur expertly fished out. And then we see two more… Once in a cardboard box, the babies all look remarkably well, if a little damp, and we soon feel confident enough to take them outside and release them into the woodland around the flume. Then it is back to work, excitement over… Or is it? 15 minutes later, we hear ‘maus!’ again and the rescue efforts swing into action once more. This one, surely from the same nest but having been in the water that much longer, looks in a bad way. But we get some heat into it under one of the saltmarsh lamps and gradually it starts to twitch, and then raise itself on its little paws, and then open its eyes, and finally we feel able to take this one outside too where it scuttles off into the undergrowth. We all feel good – 4 lives saved!
Next step: the first pre-wave measurements…