Fish in the River Stour Catchment Ecology, Distribution & - - PowerPoint PPT Presentation
Fish in the River Stour Catchment Ecology, Distribution & Habitat Dan Hayter Environmental Monitoring Team (Fisheries Specialist) 12 th February 2015 Environment Agency Fisheries Monitoring teams Data collection from electro-fishing
Dan Hayter Environmental Monitoring Team (Fisheries Specialist) 12th February 2015
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Environment Agency – Fisheries
Monitoring teams
Fisheries, Biodiversity & Geomorphology team
Enforcement team
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Why Monitor Fish?
National & International drivers & commitments Environment Agency has a duty to maintain and improve fisheries Fisheries monitoring is vital to help us deliver
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Current and Historic Monitoring Sites
Current Monitoring Sites Historic Monitoring Sites Legend
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What does fish data tell us?
Status (health) of river ecosystem
Is the water quality & quantity ok? Is there enough good quality habitat?
Evidence...what is wrong and where? Stock levels, trends, population dynamics etc Info for anglers
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2 4 6 8 10 12 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 Mean Density (Ind./100m2) Density of fish species (>99mm) on the Middle Stour
Chub Dace Eels Perch Pike Roach
100 200 300 400 500 600 700 800 900 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 Mean Standing crop (g/100m2) Standing crop of fish species (>99mm) on the Middle Stour
Chub Dace Eels Perch Pike Roach
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Replacement scale Original scale
Fish scales used to age fish
11 2 4 6 8 10 12 14 16 18 20 25 40 55 70 85 100 115 130 145 160 175 190 205 220 235 250 265 280 295 310 325 340 355 370 385 400 415 430 445 460 475 490 505 520 Number of fish Fish Length (mm) 2 3 4 5 6 7 13
Chub Middle Stour 2012 Fish Ageing – Length Frequency Graph Roach Middle Stour 2012
100 200 300 400 500 600 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 Number of fish Fish Length (mm) 1 2 3 4 5 6 7 8 9 10
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Angling in England & Wales
Around 1 million anglers were licensed in 2005
Approx £25 million funding to Environment Agency
These anglers spent £1.16 billion on fishing in 2005 Important to the rural economy Help protect the environment
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Roach, Rutilus rutilus
Common & versatile species, dominates in slow, deep reaches Spawns in vegetation in shallow water Overwinters in shoals in deep, slow flowing water Fry refuge areas important during spate Diet – anything small enough!
Max size 35cm+ & reach 12+ years old
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Chub, Leuciscus cephalus
Widespread & versatile, common in faster reaches Spawns in shallow water mainly on gravels Diet – insects & larvae, crustaceans & fish Max size 55cm+ & over 15 years old
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Widespread but prefers shallower, faster flowing water Spawns in shallow water on gravel riffles Warm water impacts on egg survival Diet - insects & larvae, crustaceans and drifting food Max size 25cm+ & over 7 years old
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Dace, Leuciscus leuciscus
Brown Trout, Salmo trutta
Common on some tributaries and headwaters but rare in middle and lower reaches
Spawns in clean gravels (build redds) Diet - insects & larvae, crustaceans and drifting food Size commonly up to 35+cm but can grow much larger
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Eel, Anguilla anguilla
Endangered (95% decline in elvers since 80’s) Still widespread in lower reaches but in small numbers Barriers and loss of habitat big factors in decline Versatile, but favours woody debris, thick vegetation and
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Problems for fish
Barriers to migration Channel modifications
Land management
Pollution Warm water
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Improvements
Fish & eel passage
» Barrier removal and fish pass installation » Benefits all fish species
Sustainable abstraction Catchment Sensitive Farming
» Benefit all species
Improve channel diversity
» Channel narrowing & gravel areas
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Improvements cont
Woody debris & brushwood structures
» Cover and promotes natural processes to benefit all species
Off-channel refuge/backwater creation
» Important for fry during spate conditions
Tree planting & shading
» Benefit all species
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