§ Mr. William RossTo ask the Secretary of State for Northern Ireland how many salmon and grilse were caught in River Bush in each of the last 10 years; how many were recorded passing upstream at Bushmills each year; how many each year are believed to have spawned naturally and successfully; what is the estimated number of(a) parr and (b) smolts produced each year; what has been the estimated survival rate of smolts to adults; how far the information acquired corresponds with information gained from other studies; and if he will make a statement.
§ Mr. Peter Bottomley[holding answer 26 March 1990]: Following is the information:
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Number caught (angling in restricted stretches Number passing upstream Estimate number spawning Number of smolts Marine survival smolt to adult percentage 1988 474 2,783 2,442 22,994 12.5 1989 140 733 579 17,812 4.3 1 No data due to breakdown of electric barrier. The River Bush experiment is highly regarded internationally and the data produced are regularly integrated with those from other studies, through the ICES salmon working group on which DANI scientists are represented. This is a continuing process and current comparisons are not yet available.
§ Mr. William RossTo ask the Secretary of State for Northern Ireland what information he has as to the total catch of salmon at sea which are bound for(a) the Foyle river system including the Roe and the Faughan, (b) the River Bann system, (c) the River Bush and (d) other salmon rivers in Northern Ireland; and what percentage of the total run this represented in each of the last five years, or as much of such information as is available to him.
§ Mr. Peter Bottomley[holding answer 26 March 1990]: Following is the information:
(a) None.
(b) None.
(c) For River Bush wild salmon stock information is only available for the last three years as follows:
Year Estimated sea catch of salmon bound for the River Bush Relevant percentage of total run 1987 4,804 68.5 1988 5,237 65.3 1989 5,931 89.0 (d) None.
§ Mr. William RossTo ask the Secretary of State for Northern Ireland what information he has on the age at which salmon smolts in the River Bush migrate to the sea; how long they normally spend there; what percentage of an annual cohort returns are(a) one sea winter, (b) two sea winter, (c) three sea winter and (d) four sea winter fish; and what percentage of the annual salmon run over the last five years has returned in each month of the year.
§ Mr. Peter Bottomley[holding answer 26 March 1990]: In the last 10 years 25.1 per cent. of River Bush smolts have migrated to sea at one-plus years of age, 73.8 per cent. at two-plus years of age and 1.1 per cent. at three-plus years of age.
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Year Grade of staff leaving1 Replacement action 1986–87 Principal scientific officer Post filled by permanent appointment Laboratory attendant None, the post was dropped fom complement 1987–88 None 1988–89 None 1989–90 Higher scientific officer Post to be advertised for permanent appointment The percentage of annual returns of various sea ages is as follows (average of last 10 years):
- (a) 1 sea winter : 87.8 per cent.
- (b) 2 sea winter : 12.2 per cent.
- (c) 3 sea winter : 0
- (d) 4 sea winter : 0
Mean Percentage Monthly Returns 1985–89 Month Percentage of Run January 0.007 February 0.020 March 0.280 April 0.587 May 1.283 June 3.944 July 26.215 August 25.655 September 14.656 October 15.079 November 2.402 December 1.276 The three places of decimals indicate activity throughout the year rather than precision.