An integrated assessment of the impact of anchoring on seafloor integrity (MSFD Descriptor 6) within a major bunkering area of the Maltese islands

Abstract

International shipping is a fundamental driver for the global economy. As the shipping industry grows, so does the demand for high-capacity vessels, which led to concerns on how these vessels interact with the marine environment. While waiting to access port facilities and services, vessels may anchor to reduce fuel consumption and to prevent the vessel from drifting. However, anchoring is one of the primary causes of mechanical disturbance to the seafloor and benthic habitats and ecosystems. Locating and quantifying anchoring pressure would enable the marine environment to be managed better so that damage to the seafloor as a result of anchoring is mitigated. The Automatic Identification System (AIS) can be used for identifying and quantifying the anchoring pressure in those areas under investigation. AIS transmits information (e.g. position, type, size) of a vessel to other vessels and coastal stations. This study aims to assess the anchoring pressure in one of the bunkering areas strategically located around the Maltese Islands by using the AIS data collected by the AIS antenna located at the University of Malta, Msida. Anchoring pressure is determined through the development of an arbitrary index using the AIS data. Additionally, the same AIS data is used to produce several GIS maps depicting the location and size of the vessels within the confines of the bunkering area as mentioned above as well as several plots depicting anchoring pressure based on vessel type, seasonality, and density.