Oh dear oh dear oh dear. It's not meant to go like this, but then again perhaps it is.
This is how it is. There are now two chicks, one has perished. It is no more. Predation? I don't think so, the site is just too tricky to access. The problem is this...
Yes, it is a nest with two chicks in it. What's the matter with that you say dear reader? Well it isn't the original nest, the nest that was high enough to hatch three and a half eggs. It's new, it's low, and it is rubbish.
After the initial hatching was over, the adults moved the functioning cup of the nest a little further down the pile which I can understand as it meant that they could put fresh material in etc etc. It then seemed that as the week went by they slipped further down the pile and closer to the water. This wasn't a problem while the top of the nest was still above the high tide mark, but now it isn't. Each time they have a new site the adults build, and when they build they take any material they can get their shiny little beaks on and the best source of nesting material is a nest that is not being used. Henceforth the top of the best nest is falling and there is no easy point for them to the chicks out of the water when high tide arrives. As Coots are not one of those waterbirds renowned for carrying chicks on their back the young may not be able to get out of the water at high tide, get a chill and drift off down the Wandle in their terminal torpor.
To exacerbate this scenario, they have now started building a completely new nest (as per the picture) and this is being built a few yards down from the original nest. When I last watched them the adults were extremely busy taking from the good nest and building up the new. To such an extent that the original (once good) nest will now be totally covered during high tide as will the new nest leaving the chicks nowhere to go when the tide rises. The adults, while being quite industrious have rather screwed the whole thing up.
I suspect that when I next visit, there will be less than two chicks and quite possibly less than that.