Malta - Coastal Cliffs

"The coastal cliffs of the Maltese Islands are characterised by vertical or near-vertical rock faces rising from the sea to heights of up to 70-130m above mean sea level and continuing below it down to depths of 80m in places. Steep slopes which are often terraced and which have been under cultivation for hundreds of years cap parts of these cliffs whereas spectacular boulder screes (known locally as rdum) dominate others. Coastal rdum landscapes typically consist of an Upper Coralline Limestone block overlying Blue Clay. Erosion and recession of the latter causes the cliff edges to collapse under their own weight resulting in massive boulders which then move downslope over the mobile clay, particularly when this is wet and plastic. A boulder scree thus results at the foot of the escarpment and, where the rdum is close to sea level, extends downslope to the sea where it may form a boulder shore in places. A perched aquifer is present in the permeable Coralline Limestone, supported by the Blue Clay aquiclude. Seepage from this, in the form of scarp-foot springs, results in the slopes below the rdum receiving abundant water during the wet season and beyond. Because of their relative inaccessibility both the vertical cliffs rising from the sea and the rdum with their boulder screes provide important refuges for many threatened and/or specialised species of Maltese flora and fauna, including many endemics. 

Within the cliff systems are found examples of many unusual central Mediterranean coastal habitats, including clay slopes, boulder screes, and rocky ledges on the cliff faces and karstic limestone plateaux beyond the cliff edge. Gorges cut by extinct streams interrupt the cliffs in places and where these dry valleys (known locally as widien) open on the coast, they occasionally give rise to saline marshlands and sandy and shingle beaches. Away from the mouth of these valleys are found characteristic watercourse and spring habitats. With these habitats are associated rupestral, steppic, garigue and maquis assemblages, as well as those of temporary rainwater rock-pools that form on the karstic rock, and those of watercourses and freshwater wetlands. Because of the heterogencity of the terrain, mosaics of assemblages form, giving rise to a very rich biodiversity The fauna of the coastal cliffs includes some of the rarest of Maltese animals. 

For example, the endemic snail Lampedusa melitensis occupies a very precarious habitat of a few tens of square metres on a small area of boulders on the south-west cliffs of Malta, while two other rare, endemic snails (Lampedusa imitatrix and Trochoidea gharlapsi) are found in just a few cliffside localities. The cliffside vegetation is dominated by shrubs and is especially important due to the presence of a large number of endemic plant taxa, including the Maltese Rock Centaury (Palucocyanus crassifolius - the National Plant of Malta), the Maltese Salt Tree (Darniella melitensis) and the Maltese Cliff-Orache (Cremnophyton lanfrancoi).... Locations include Malta, Ghawdex, Kemmuna, Kemmunett islet and Filfla islet (Central Mediterranean)."


Source: UNESCO World Heritage Tentative List

Aerial view of Filfra - area of 60,000 m2, a small uninhabited islet 5km south of Malta supporting large colonies of seabirds. Thanks to Jean-Pierre of France.