To ask the Secretary of State for Environment, Food and Rural Affairs what assessment he has made of the size of the salmon population in (a) the River Mersey and (b) all rivers in the Merseyside region, (i) on the latest date for which information is available and (ii) (A) two, (B) five, (C) 10 and (D) 15 years ago.
The current assessment of the salmon population size in the Mersey catchment covers two elements of the fish's life cycle:
1. Numbers of adult fish entering the Mersey Catchment.
2. Numbers of juvenile salmon in the Rivers Goyt and Bollin.
No distinction is made between (a) River Mersey and (b) All Rivers in the Merseyside region when assessing adult salmon. All monitoring of adult numbers is carried out at the Woolston Weir Fish Pass and Trap in Warrington.
The Woolston fish pass was adapted to trap fish in 2001, shortly after evidence was collated to confirm the arrival of adult salmon in the river. It has since been run in the autumn of each year.
|Number of adult salmon||Number of days fish trap is operated|
|(1) Shut for health and safety modification|
The number of days spent trapping varies from year to year and is dependent upon the amount of resource available.
Video technology is currently being developed for the trap to enable the remote counting of adult salmon all year round.
Juvenile salmon distribution is currently monitored on the River Goyt by electric fishing for young fish and the counting of adult redds (nests). Since young salmon were discovered on the River Goyt in 2001, they have been counted in small numbers every year on the river.
|Number of juvenile salmon||Number of surveys in the lower Goyt|
Juvenile salmon surveys will start on the River Bollin in 2010. This river has now been opened up to adults by the building of two new fish passes, developed as part of the Environment Agency Mersey Life project.