§ Mr. William Rossasked the Secretary of State for Northern Ireland what is his estimate of the number of salmon redds, alternatively spawning salmon, needed to maintain stocks of salmon in (a) the Foyle system, (b) the river Bann and all its tributaries, including those flowing into lough Neagh and (c) each other river system in Northern Ireland; and by what percentage the needs were met or exceeded on the average of the last five years for which figures are available.
§ Mr. ButlerThe information requested is available only for the Foyle system. Two Canadian scientists carried out an investigation of the salmon stocks of the Foyle area in the mid-1970s and, based on research undertaken in north American river systems, suggested that the spawning requirement for optimum yield could be 7,746 redds spread evenly throughout the system. The average number of redds counted in the five-year period up to and including the 1983–84 spawning season was 3,389 or 43.8 per cent. Counting of redds is by visual observation when water conditions are suitable and the annual count, while very useful in indicating trends, cannot be regarded as necessarily reflecting the actual number of redds in any year.
A research project in which the Department of Agriculture is engaged in the river Bush is to provide scientific information on the required level of salmon ova deposition in this local river. The results should be applicable to river systems throughout Northern Ireland.