My Lords, I apologise to my noble friend for jumping in here, but I would like to go on for a bit to address exactly what the noble Lord, Lord Krebs, has said. I could not concur more strongly with the aspersion that he made against the mantra of fishing at the level described as the maximum sustainable yield. I reiterate that it is absolutely perilous to do so.
The MSY represents an unstable equilibrium. It is akin to the equilibrium of an egg balanced on one of its ends; it is almost impossible to achieve even for an instant. One small disturbance will topple the egg, which is liable to fall on the table and break itself on a hard surface. In the case of fish stocks, that hard surface is total species extinction.
It is by an unfortunate misuse of terminology that the maximum possible harvest has acquired the misleading description of “maximum sustainable yield”. The words “maximum” and “sustainable” have specious connotations, which are spurious in this case. For a start, as I have emphasised, this level of harvesting is not sustainable. Moreover, if it could be sustained, it would not correspond to an economic optimum. To achieve this level of harvest requires an uneconomic expenditure of effort.
A vision of fish-stock ecologists is that we could harvest an ample supply of fish from an abundant stock with the least expenditure of effort. This would require the fish stocks to have an opportunity to regenerate themselves by the suspension of excessive harvesting. Such circumstances prevailed in the years immediately following the two world wars, during which fishing in European waters had been largely suspended. This did not last for long. Soon, fishing fleets armed with technological innovations were chasing an ever-diminishing supply of fish through marine deserts of the fleets’ own making.
In the face of the depletion of fish stocks, British fishermen have adhered to the myth that they have been robbed of fish by the depredations of foreign fishing fleets. They now urge the Government to give them exclusive access to our supposed national waters and to allow them to substantially increase the size of their harvests. This is a recipe for disaster. I thank my noble friend for allowing me to jump in.