Zona fil-Bahar fl-Inhawi tad-Dwejra (Ghawdex)

Name of Site:  Zona fil-Bahar fl-Inhawi tad-Dwejra (Ghawdex) 

Year of designation: 2012 

Area [ha]: 228.61

 Annex 1 Protected Habitats:

  • 1120  Posidonia beds (Posidonion oceanicae)
  • 1170  Reefs
  • 8330 Submerged or partially submerged sea caves

 

Importance:

The Dwejra coastal area in Gozo has been identified by the Structure Plan for the

Maltese Islands as an area of potential international scientific importance in view of a complex of features of interest known from here, including geological, geomorphological, ecological, archaeological, historical and aesthetic aspects. Considering Posidonia meadows, there is an extensive, though non-continuous, bed within the area of ‘Il-Bajja tad-Dwejra’ (Dwejra Bay) where the sea-grass strands are dense and healthy. Small patches of the sea-grass also occur on bedrock in other parts of the area. The Posidonia oceanica meadows within this site are considered to be isolated since there is little or no continuity with meadows present in other coastal areas due to the prevailing deep water off most of the eastern coast of Gozo (Posidonia does not grow in deep waters). A baseline survey on the extent and character of Posidonia oceanica (L.) Delile Meadows in the territorial waters of Malta was carried out in 2002. Following examination of various parameters during this Posidonia Baseline Survey, the meadow and the general environmental conditions have been classified as normal within this site. The classification used was based on Pergent et. al (1995). Marine invertebrates associated with the Posidonia oceanica meadows include numerous species of molluscs, polychaetes, crustaceans and echinoderms that seek refuge in the leaf canopy and root-rhizome layers, hence being quite inconspicuous. Additionally, several species of sponges, corals, sea urchins, sea stars, crabs and anemones occur within this site. Of particular note is the existence of small populations of Pinna nobilis, Centrostephanus longispinus and Scyllarides latus, and Epinephelus marginatus which is frequently encountered by divers. A single sighting of Tursiops truncates (Baldacchino & Schembri, 2002) has been reported in this area. These are amongst the species which are afforded international (apart from national) protection. Rocky Reefs are present throughout the area and may either be reefs that rise vertically from a sandy bottom littered with large boulders to join submarine bedrock platforms or submarine continuations of emergent cliffs. Associations with Flabellia petiolata and Peyssonnelia squamaria cover most reef areas. A total of five fully submerged caves and six semi-submerged caves are present in the area. Several of these caves support very diverse assemblages characteristic of semi-obscure caves, that is those with dim light conditions but not complete darkness. The macrofaunal component of this assemblage type consists of a large number of bryozoans, sponges and serpulid polychaetes. The submerged caves mostly located in the northern half of the site have a very complex physiognomy and a bottom characterised by fine sediment. The largest of these appear to be two caves lying below the shore of Il-Hofra ta’ Birwin and Iz-Zerqa area. The emergent caves, which are distributed throughout the study area, also have a very complex physiognomy, both underwater and above sea-level. The bottom inside the emergent caves consists of bedrock, with small boulders, cobbles and pebbles present in some places.