ANNUAL DRAWDOWN SPRINGS SOME SURPRISES!

IN THE annual semi-tidal Thames ‘drawdown’ the river is allowed to drop to the full extent of the tide, exposing riverbed and gravel banks that are covered with water for the other 11 months of the year.

On my latest well-timed beachcombing trip I found a lot of what I thought were zebra mussels – they were in fact of the quagga variety, an alien species.

However, most of the quagga shells were empty, and according to regular monitoring by the Zoological Society of London the live population is in huge decline. Quagga mussels were first discovered on the semi-tidal Thames just three years ago, and what I find enthralling is that these invasive species arrive, flourish massively and then, in a relatively short time, decline equally dramatically. This has happened with mitten crabs, signal crayfish and now zebra mussels and Asian clams.

My most interesting find came from the skeleton of a garden chair with heavy green braid attached. About 4m away was a clump of branches, and the braid led me to that. A grip lead was sliding on the braid so I kept going until I found a HUGE catfish hook, at least a 7/0, with a bag and a label attached.

When I cleaned the mud off, it proved to be for a haggis. Now, offal is a recognised catfish bait, but most anglers would take it out of the bag before use!