Fish

BISHOP’S MEADOW – River Modifications – 2014

The Environment Agency and The Surrey Wildlife Trust recently carried out some modification works on a section of the river Wey running though the Bishop’s Meadow with the purpose of improving the river environment and increasing benefits to fish and water-borne invertebrates.

The modifications involved securing locally sourced logs to the bed of the river, to act as deflectors, diverting and speeding up the water flow. The increased flow will help to deepen existing pools and scour the gravel bed of the river, preventing silt build-up and keeping the gravel clean, improving the spawning habitat for both brown trout and coarse fishes. Deeper, more pronounced pools also provide good holding habitat for adult fish whilst shallow, fast flowing gravel riffles provide spawning opportunities for trout and other gravel spawning species such as dace. Fast flowing riffles are also vital habitat for aquatic flora such as water crowfoot and are important for a wide range of freshwater invertebrates.

“Mats” of branches and brushwood were also placed to provide juvenile nursery habitat and cover for adult fish. These “mats” will increase flow variation and provide sheltered lies where fish can conserve energy and keep an eye out for food drifting in the main current.

Vic Green – Chairman

Catchment and Fishery Overview

The Wey North forms the northern arm of the upper Wey catchment. It rises from a chalk aquifer near Alton, Hampshire and runs eastwards through Upper Froyle and Bentley to Farnham more-or-less parallel to the A31. At Farnham the river turns south towards Tilford where it joins the South Wey.

Much of the North Wey has been modified for milling, agriculture and flood defence over the years. However, despite these stresses to the river habitat, the North Wey through Bishop’s Meadow is reported to support a healthy mixed fishery with populations of chub Leuciscus
cephalus, dace Leuciscus leuciscus, roach Rutilus rutilus, perch Perca fluviatilis and brown trout Salmo trutta. The river here is also known to support bullhead Cottus gobio, a protected species under the European Habitats Directive.

Despite not being a true chalk stream (i.e. a stream rising from and flowing over chalk geology), the river has many chalk stream characteristics including established communities of water crowfoot Ranunculus spp and starwort Callitiche spp.

The Wild Trout Trust have kindly visited Bishop’s Meadow and produced a report that primarily focussed on options to enhance the river Wey through the meadow for the benefit of wildlife and local people.