Analysis: Incident highlights the problems that lie ahead

IN TERMS of scale this is a small spill, only 10 per cent of the platform's daily production over the past four to five days and a fraction of the estimated 585,000 tonnes spilt from the Deepwater Horizon in the Gulf of Mexico.

As with the Gulf spill, the oil is natural crude which will break down relatively quickly through microbial action and it is a fair distance from shore so the probability of landfall is slight at this stage.

So should we be concerned? Any spill is harmful to the environment in some way and whilst this is not a major incident it will cause some damage. More critically in the cooler waters of the North Sea microbial action takes longer and so the oil remains harmful for longer as well.

The big problem in the Gulf was the depth of the incident - 1,500m. In the North Sea the depths are less than a tenth of this and the technology far more straightforward.

Royal Dutch Shell is among a number of companies keen to extract oil from deeper sources to the North west of Shetland.

This oil is needed if North West Europe is to maintain its own oil and gas supplies, but it carries the dangers of deep water in a cold and stormy climate - the worst of both worlds.

After BP's experience in the Gulf, and in spite of it, many oil companies were reticent to see significant changes to safe practices in other parts of the world. Whilst this is an unusual event - the North Sea Platforms do have a relatively good safety record - it does highlight the problems ahead.

• Dr Simon Boxall is an oceanographer at the University of Southampton