Tuesday 9 November 2010

Water, Water

I was busy with various things that kept me largely in the Centre today, considering the weather not the toughest choice. In very heavy rain first thing all I saw of note from the Tern hide were 2 dunlin flying about. I could only see 2 goldeneye, it could be that the others were lurking out of sight, but it could be that yesterday's arrivals were actually just en route somewhere else when they were forced down by the wind and rain in the early hours.

When I went to lock up the Tern hide a kittiwake had just been seen over the lake, another new bird for the BTO Challenge. Sadly there was no sign of the ring-billed gull reported the other day, although the gulls were mostly in the north-east corner of the lake and so hard to see well. There was a flock of dunlin, numbering at least nine, but I think more.

The heavy rain today caused the Dockens Water to flood for the first time this season, it overflowed into the alder carr and thence into the main body of Ivy Lake. This input of acid New Forest water into the more neutral to alkaline water of the lake both raises the lake level and changes the pH, at least a little. This last point may have something to do with the increase in Crassula helmsii in the last two years. This plant likes more acid conditions and in the last two years no river water has been added to the lake from the Avon, but the Dockens Water has flowed in several times. The other effect of this rush of water might be to pull the sea trout into the Avon and even into the Dockens, where they will eventually spawn.

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