THE UK Government appears reluctant to sign the International Maritime Organisation’s (IMO) new convention on ballast water control, which is in stark contrast to its punctiliousness over observance of other inter-governmental agreements. It suggests conservationists’ suspicions that there is a connection to its attitude to ship to ship oil transfers may have substance, although it does not seem to have prevented oil-producing Norway from signing.

The use of ballast water to stabilise ships without cargoes is of course well established. Most of the marine species in ballast water loaded at one side of the world will not survive in foreign waters. But some do. They can alter the entire local ecology, and can contaminate local seafood.

Conservation body WWF highlights the example of comb jellyfish from North America (Mnemiopsis leidyi) which arrived in the Black Sea in ballast water in 1982. They had no enemies in their new home, and propagated at an alarming rate. By the mid-1990s, they accounted for 90 per cent of the total biomass in the Black Sea, a biomass more than the total annual global fish catch. It led to the near-collapse of Black Sea commercial fisheries. The species quickly spread into the neighbouring Azov Sea.

WWF concluded that alien invasive species can be as damaging as oil spills, and their effects much more persistent. So the community group Cromarty Rising is to be congratulated for highlighting the UK Government’s attitude to IMO’s new convention, when so close to becoming law.

The issue also underlines the dysfunctionality of present arrangements. Edinburgh is charged with protecting Scotland’s terrestrial and marine environment; but the Department for Transport in Whitehall and its Maritime and Coastguard Agency in Southampton decide the level of risk presented by oil transfers or alien species to Scotland’s seas.

That is a matter of concern, the more so given environmental protection is hardly likely to strengthen after Brexit.