§ Mr. William Ross
To ask the Secretary of State for Northern Ireland what sums have been expended by his Department in each year since the Department of Agriculture first leased and began investigations into the salmon in the River Bush; and how many reports have been produced as a result of that work; how many and which of these reports have been published for sale to the general public; and if he will now publish a comprehensive report of all the findings in a form easily understood by the general reader.
§ Mr. Ancram
The total expenditure by the Department in each year is not available. However, the running costs574W relating to the project are published in the annual reports on the sea and inland fisheries of Northern Ireland, copies of which are in the Library. Forty-eight scientific reports arising from the River Bush project have been published. A comprehensive report will not be published until the project has been completed. However, annual reports on the project, written in layman's terms, are published in the annual report on research and technical work of the Department of Agriculture for Northern Ireland. Copies of the scientific publications and the annual reports are available, on application, from the Department.
§ Mr. William Ross
To ask the Secretary of State for Northern Ireland what is his estimate of the area of spawning grounds available to grilse and salmon in the River Bush catchment area, the number of such fish that this area can accommodate, the number of fish counted in such areas in each of the last five years for which figures are available, the number of parr produced in each of the last five years and the number of smolts migrating in those years; and what is his estimate of the optimum numbers of each cohort of such mature and juvenile fish.
§ Mr. Ancram
The total usable salmonid nursery habitat, comprising spawning and nursery habitat as both are necessary to produce juveniles, is 41.06 hectares. The internationally recognised methodology for measuring utilisation of habitat is ova deposition, rather than number of adult fish, as number of ova per fish can vary considerably. From the research to date, it has been estimated that the overall optimum ova deposition for the River Bush is 2.46 million ova. Ova deposition actually achieved over the past five years is set out in the table. The target deposition has been exceeded in three out of the last five years.
Year of run Ova deposition (millions) 1988 4.60 1989 1.06 1990 2.44 1991 2.97 1992 2.72 11993 1 1Not yet collated.
The number of juvenile fish—fry and parr—on the River Bush is ascertained by electrofishing surveys at 137 sites covering all the significant spawning and nursery areas. The table sets out the results of the survey.
Year Average number salmon 0+ per 5 min. fishing 1988 8.26 1989 16.20 1990 5.65 1991 12.48 1992 13.04 5 year average 11.25
It should be noted that the surveys are not fully quantitative. They should provide indices of abundance to compare between years and should not be interpreted as indicative of the number of salmon comprising the standing stock at the time of the survey.575W
The wild salmon smelt migration is set out in the table.
Year Number of smolts 1988 22,994 1989 17,812 1990 17,354 1991 18,471 1992 10,006
It should be noted that the target ova deposition set by the Department to achieve optimum recruitment may, due to biological and environmental conditions occurring after ova deposition, result in a wide range of recruitment—that is, an egg-based target aims to ensure full utilisation of habitat, but environmental and predation factors influence the eventual number of fish produced. As a result targets cannot be set for these categories of fish and the statistics given on juvenile and smolt numbers are of limited application to the estimation optimum numbers requested as there are no juvenile or smolt targets set.