bervie water – proposals for a catchment scale study esk rivers & fisheries trust
TRANSCRIPT
CATCHMENT OBJECTIVES
• BIOLOGICAL ASSESSMENT
• HYDROLOGICAL ASSESSMENT
• GEOMORPHOLOGICAL ASSESSMENT
BIOLOGICAL ANALYSISCOMMUNITIES OF INVERTEBRATES HIGHLIGHT THE ON-GOING
RIVER FUNCTIONS
DETECTS IMPACTS and ECOLOGICAL STATUS• Pollution, acidification, eutrophication, and metals• Score the invertebrates according to presumed sensitivity
Biological Monitoring Working Party (BMWP) – based on families Ephemeridae (May Flies), Perlidae (Stone flies) – score 10 Caenidae (angler’s curse) – score 7 Gammridae (shrimps) - score 6 Baetidae (olives) - score 4 Hirudidae (leeches) - score 3 Chironomidae (midge larva) – score 2Oligochaeta (worms) - score 1
Proportion Silt Sediment Sensitive Invertebrates – alternative to quantifying the volume of deposited fine sediment (<2mm) in the river bed
PROPORTION SEDIMENT SENSITIVE INVERTEBRATES (PSI)
PSI = ∑Scores for sediment sensitive groups (Highly& Moderate)/ ∑Scores for all sediment sensitive groups
PSI River Bed condition100-81 Minimally sedimented/unsedimented80-61 Slightly sedimented60-41 Moderately sedimented40-21 Sedimented20-0 Heavily sedimented
1 2 3 4 5 6 7 8 9 100
2
4
6
8
10
12
14
16
18
20
22
24
Bervie Electro-fishing Results
trout 0+trout 1+trout 2+salmon 0+Salmon 1+total
Site No
No.
of
Fis
h C
aught
HYDROLOGICAL ASSESSMENT
AVERAGE RIVER FLOWS ACROSS SCOTAND HAVE INCREASED BY ~ 20% OVER THE LAST 30 YEARS AFFECTING
• RIVER BANK EROSION• FLOODING• IN-STREAM HABITAT• INCREASED SEDIMENT TRANSPORT
Erosion downstream of Mondynes
Siltation at Tipperty