Changing attitudes - the dynamic sand dune, a new paradigm?

Historically unstable dunes have been identified as a threat to human activities or assets. Overwhelming agricultural land, farms and other infrastructure by blowing sand and the threat of flooding have resulted in a wide variety of measures being adopted to stabilise and 'protect' them. 'Engineering' dunes to prevent sand movement and create structures which defend the land from the sea has been the principle management objective, especially on coasts where shoreline erosion is evident. Even in dune areas identified for their conservation significance 'protecting' the dune from erosion has often been a major preoccupation, especially where recreational use is seen as a key factor in creating erosion. Looking at the sand dune from an ecological perspective and learning lessons from the way in which sandy beaches and sand dunes respond to natural perturbations in the environment (climate change, sea level rise and perhaps most importantly storms) suggest that they made be more resilient than past protective measures suggest (Doody 1989; Doody 2001). In this context it is vitally important to understand dune dynamics and its role in creating high quality and diverse habitat.

In Holland large parts of the country are 'protected' from flooding by the sea by massive sand dune barriers. The body of the dune areas are also important as a source of drinking water and used for recreation. Sand dune stabilisation began as far back as the 13th Century and has been both extensive and intensive. The perception that any bare sand could not be tolerated resulted in most of the dune landscape having little or no natural dynamics. Recently this paradigm has begun to change. Active intervention to create open dune habitat and improve the conservation value of some areas has been suggested. The high cost of protection and the absence of natural dune dynamics and the corresponding reduction in nature conservation value are sighted as reasons for adopting a more flexible approach to preventing sand movement (van der Meulen & van der Maarel 1989; van Bohemen & Meesters 1992). The paper also suggests that options which "add to the natural values of the dunes" may be more cost effective than traditional approaches to sea defence. Not only has the view of sand dune dynamics begun to change but more generally so has the approach to coastal defence policy. Since 1990 in the Netherlands 'dynamic preservation' of the coast has become an integral part of policy and with it beach nourishment as a management tool (Hillen & Roelse 1995).

Comment: These approaches have been pioneered at sites such as the Sefton Coast. The island of Rømø in Denmark is another example, in this case recreational use is seen as a means of 'opening up' the dune.

References

Doody, J.P. 1989. Management for nature conservation. Royal Society of Edinburgh Proceedings. Section B (Biological Sciences), 96., 247-265. Abstract...

Doody, J.P. 2001. Coastal Conservation and Management: an Ecological Perspective. Kluwer, Academic Publishers, Boston, USA, 306 pp. Conservation Biology Series, 13

Hillen, R. & Roelse, P. 1995. Dynamic preservation of the coastline in the Netherlands. Journal of Coastal Conservation, 1/1., 17-28.

van Bohemen, H.D. & Meesters, H.J.N. 1992. Ecological engineering and coastal defence. In: Coastal Dunes. Geomorphology, Ecology and Management: Proceedings of the Third European Dune Congres, eds.Carter, R.W.G., Curtis, T.G.F. & Sheehy-Skeffington, M.J.A.A. Balkema, Rotterdam

van der Meulen, F. & van der Maarel, E. 1989. Coastal defence alternatives and nature development perspectives. In: Perspectives in Coastal Dune Management, eds.van der Meulen, F., Jungerius, P.D. & Visser, J.H.SPB Academic Publishing bv, The Hague, 183-195.