Ships use ballast water to adjust their stability and trim when sailing without cargo, when partially loaded and during bad weather This is important both for safety reasons and for the economic operation of vessels in the modern shipping industry.
Decisions regarding consenting of ballast water arrangements are subject to the National Marine Plan published in 2014. The National Marine Plan contains a number of relevant policies relating to environmental factors (including the potential for the transfer of non-native species through ballast water) and potential consequences for other marine users.
Ship-to-ship transfers of oil as cargo in territorial waters are regulated by The Merchant Shipping (Ship-to-Ship Transfers) Regulations 2010 (as amended) which came into force on 31 March 2012 and provide a framework governed by the UK Government which prohibits the transfer between ships of cargoes consisting wholly or mainly of oil unless the ships are within harbour authority waters and authorisation has been given by the harbour authority. The Regulations also provide that ports and harbours need to apply to the UK Government for an oil transfer licence to allow them to authorise such operations. This requires an Environmental Assessment to be carried out and an Environmental Statement to be produced which will be used in support of the application to the Secretary of State. The Environmental Assessment is required in order to assess the likely significant effects of the proposed cargo transfers on the environment.
The above Regulations do not provide a role for Scottish Ministers in consenting to programmes of ship-to-ship transfers in territorial waters adjacent to Scotland. The Regulations are made under section 130 of the Merchant Shipping Act 1995 and the subject matter of that Act is currently reserved to the UK Government. The decision on whether to issue an oil transfer licence in Scottish waters is for the UK Government.
Scottish Ministers have requested that the UK Government devolve these powers to Scotland.