26 February 2015

natural beach cleaning

We are all aware of the deleterious effects of mechanical beach cleaning on coastal dune biodiversity and, ideally, we would like to see fore dunes look something like this:

Crymlyn Burrows fore dunes and strand line

But, at the moment, a large stretch of the fore dunes (and strand line) on Crymlyn Burrows looks like this:

Strandline on Crymlyn Burrows after stormy high tides (February 2015)

This is not the result of mechanical beach cleaning, which never takes place along this part of Swansea Bay. It is the result of a natural process, the combination and coincidence of very high tides and very stormy weather. This process must have happened many times in the history of Crymlyn Burrows and it must have a catastrophic effect on strand line animals and plants. This may explain why species like the rare Beechcomber Beetle, Nebria complanata, show such alarming fluctuations in population size along our shores (see Ian Tew's post on this blog, 19/10/14). The amount of sand translocated from the Crymlyn Burrows foreshore recently has been significant, much of it deposited on the semi-fixed marram dunes just behind the fore dunes. Where sea and wind action has been intense, fore dune erosion has been spectacular:

Excessive erosion of fore dunes on Crymlyn Burrows

Crymlyn Burrows will continue to recover and reshape its foreshore after events like this as long as it remains a dynamic, accreting system. It remains to be seen what the effects of coastal developments will be on the accretion process and foreshore biodiversity in the future.

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