The Dover ferries operate continuously in the North Sea Emission Control Area and accordingly presently burn low sulphur fuel with a sulphur content of 1%. As from 2015 the proposal is that this will be required to be reduced to 0.1%. This will mean a massive increase in costs and a very bleak future for the Dover ferries.
Any freight diverting to the short sea route from the long haul routes up North will presumably use the tunnel as this will be unaffected by the fuel price increase. The ferries are operating on a shoestring as it is. If they increase fares to cover the extra costs then the freight will go to the tunnel. If they do not increase fares then their operations will plunge deeply into the red. A bit of a dilemma.
P&O's submission to the Transport Committee in the House of Commons is on the link below, I have cherry picked a couple of passages:
"The economic impact will be massive - increasing the cost of bunker fuel by, probably 70%-87% for ships operating in Emission Control Areas (ECAs). The change of fuel from a sulphur content of 2.7% on Dover-Calais in 2004 to the sulphur content of 1% in 2011 has been an iterative process which has cost a premia of approx USD 60 per tonne on heavy fuel oil. However, the proposed change from 1.0% to 0.1% sulphur content in marine fuel in 2015 is a step change requiring a move from residual heavy fuel oil and burn much lighter distillate marine gas oil. This will be a cost premia of +70%, cUSD 420 per tonne. This will mean, from 2015, up to £3.6 billion additional annual cost for shipping within 200 miles of the UK."
"Various cost estimates place the premia for 0.1% sulphur fuel above the current 1.0% sulphur fuel in ECAs of between 70-87% extra cost. Assuming a 70% cost differential, the vessel operating costs in the North Sea sector will increase by approx 27%, and in the Short Sea sector will increase by approx 23% for P&O Ferries. The total increase in vessel operating costs in both of these sectors will, for P&O Ferries in total, be circa £60 million per annum. This will change routes which today are marginal, to be heavily loss making routes. This is completely unsustainable, with job losses inevitable."
http://www.publications.parliament.uk/pa/cm201012/cmselect/cmtran/1561/1561vw10.htm