Black Rock Brighton

The construction of the Brighton marina in 1972 provided opportunities for a newly deposited shingle beach to form between a groyne and the western breakwater. Detailed studies of this area (Black Rock Beach) showed, for example, how vegetation can develop once engineering activities cease (Packham & Spiers 2001). Between 1975 and 1996 the beach remained relatively stable and both typical and rare plants colonised, helping to create an unusual community which included the sea knotgrass, Polygonum maritimum (a plant of the Mediterranean, rare in Britain and at or near its northern range here). This community persisted until a storm in 1996 washed it away.

The study at Black Rock provides some pointers to future approaches where construction is used to protect a beach. If left undisturbed once construction is complete, then it is possible for important and rare plant communities to develop. Increasing the period of beach stability allows the development of a type of matrix and hydrology suitable for the establishment and survival of the vegetation.

The case of Black Rock is unusual, in that access to the beach be machinery was limited. More usually sea defence structures are associated with nourishment and/or reprofiling and such development is not possible. This leads to consideration of the implications of artificial engineered approaches to beach protection and their impact on coastal vegetated shingle. The implications of these approaches for the maintenance or restoration of coastal vegetated shingle are discussed next.

References

Packham, J.R. & Spiers, T. 2001. Plants along the prom: an account of shingle vegetation associated with coastal defence works at Brighton, Sussex, UK. In: Ecology & Geomorphology of Coastal Shingle, eds.Packham, J.R., Randall, R.E., Barnes, R.S.K. & Neal, A.Westbury Academic and Scientific Publishing, 174-190.