§ Mr. Andrew George
To ask the Minister of Agriculture, Fisheries and Food to what extent primary quota stocks have been affected by(a) environmental change, (b) sea water temperature change, (c) fishing effort and (d) seals and other predators, in the last three years. 
§ Mr. Morley
[holding answer 21 December 1999]: It is not possible to distinguish the exact changes attributable to environmental change and those due to sea water temperature change alone. Any temperature-related changes will in any case not be the same for all species. Cod stocks, for example, are likely to benefit from colder conditions while sole stocks may suffer severe losses from cold sea water temperatures as happened in the winters of 1962–63 and 1995–96.
The general increase in fishing effort over the past decades is primarily responsible for the low level of commercial stocks. However, the recent poor production of young cod stocks is likely to be attributable to a combination of low adult stock size and unusually warm sea temperatures.
The effects of seals and other predators on fish stocks have been the subject of multispecies research in the North Sea. Here, over four million tonnes of fish are eaten annually by other fish. In comparison, fish consumption by seals is estimated at less than 200,000 tonnes of which a significant amount is young fish and sandeels.