A spatio-temporal study of the presence of vessels within a Natura 2000 marine protected area of the Maltese Islands

Abstract

Marine Protected Areas (MPAs) are essential for preserving marine biodiversity; yet they face challenges from various human pressures, including vessel activities. This study examines the extent, spatial distribution, and temporal variability of vessel activity within the Southwest Marine Protected Area (MT101), a Natura 2000 site off the Maltese Islands, with the aim of identifying where and to what degree different vessel categories overlap with protected marine habitats. Using Automatic Identification System (AIS) data spanning 2017–2022, a cumulative, normalised vessel density approach was applied to five vessel types: passenger, fishing, cargo, tanker, and tug and towing vessel, and spatially integrated with the distribution of four Annex I habitat types, including sandbanks, Posidonia oceanica meadows, reefs, and sea caves. The analysis reveals distinct spatial and temporal hotspots of vessel presence, with passenger and fishing vessels showing consistently high overlap with ecologically sensitive habitats, particularly within bay areas and along sections of the MPA boundary, while cargo, tanker, and tug activities are more concentrated offshore. While direct ecological impacts were not quantified and vessel density serves as a proxy for potential pressure, the results highlight areas where vessel-related pressures are likely to be most pronounced and where management intervention is most urgently required. By linking long-term vessel activity patterns with habitat distribution, this study delivers a spatially explicit and transferable framework for assessing cumulative maritime pressures, providing an evidence base to support targeted, habitat-specific management measures, improved enforcement, and marine spatial planning within MPAs.