9.0 INCREASED RISK OF COLLISION BETWEEN VESSELS
9.0 INCREASED RISK OF COLLISION BETWEEN VESSELS
9.1 The potential increase in the number of vessel movements on existing routes could result in an increased risk of collision between vessels.
9.2 Marine Accident Investigation Branch46 (MAIB) incident report figures indicate that a total of 8 collisions47 and 17 groundings48 have been reported for all vessels in Scottish waters since 2000. Of these, four involved ferries: a collision between two ferries, a collision between a ferry and a fishing vessel, and collisions between ferries and a breakwater and linkspan near port. No groundings involving ferries in Scottish waters were reported in this period.
9.3 Annual marine pollution surveys, compiled from all incident reports maintained by UK Coastguard Authorities49, indicate that, of the 422 reported pollution incidents for all vessels and offshore oil and gas installations in the Scottish pollution control zone between 2002 and 2009, six of these incidents were associated with ferry services. Of these, four occurred in western Scotland and two in the Orkney and Shetland Islands. The largest event involved the spillage of 500 litres of fuel from a ferry in Ardrossan Harbour in 2008.
9.4 A study of shipping routes and the potential for collision was undertaken as part of the SEA of Marine Renewables50. The study used recorded automatic identification system (AIS) data undertaken over a two-week span in January 200651, and concluded that close quarter events (described as vessels travelling within 500m range of one another) are a common occurrence between vessels in Scottish waters, particularly along narrow waterways and near to or on approach to ports and harbours. Most of these occurrences involved vessels on common routes, vessels running beside one another, or tug or pilot boats near to port. None were classified as a "near miss" or a potential collision.
9.5 In light of the low incident rate since 200052,53, and current UK and international codes of practice and guidelines54 for all vessels in and around Scottish waters, there is a low risk of ferries colliding with other vessels.
9.6 Marine Environmental High Risk Areas (MEHRAs) identify marine areas in the UK having both a high environmental sensitivity and being at risk from shipping activity55. A total of 32 MEHRAs have been identified to date, comprising the most sensitive areas in the UK considered likely to be at realistic risk of pollution from merchant shipping. Fourteen MEHRAs have been identified in Scottish waters56 (Figure 11).
9.7 One MEHRA has been identified as being in proximity to existing ferry routes. This MEHRA, located at Tor Ness, Hoy in the Orkney Islands, consists of the western coastline of Hoy and offshore waters and has statutory designations57, significant geological features, a high concentration of seabirds and a high level of offshore fishing activity. As a provision of being identified as a MEHRA, this area has been added to admiralty charts to ensure awareness for marine vessels, and mariners are expected to exercise an even higher degree of care than usual when transiting this area56.
9.8 In addition to merchant and fishing craft, this area is currently crossed by the Scrabster-Stromness ferry service, which regularly passes through the marine area and past the coastline. As no changes are proposed to the level of service on this ferry route, there will be no increase in the number of vessel movements. In consequence, no environmental effects in MEHRAs are predicted from the Draft Ferries Plan.
9.9 Increases in the number of vessel movements are anticipated on the majority of ferry routes where changes to service level are proposed (see Appendix 1 for details). In consequence, there is an increased risk of collisions between ferries and other vessels, with consequent effects for water quality and biodiversity as a result of oil and chemical spills. However, given the existing safety regime and the low number of reported incidents for ferries in Scottish waters, this risk is considered to be low.
9.10 As no significant effects have been identified, no mitigation measures (additional to the existing safety regime) are proposed.
Figure 11. MEHRAs in Scottish waters
