afa-menu
Avon Fishing Association logo
AFA Facebook Page
Home
Conservation:
River management: Chairman's annual report:
AGM Minutes:
Avon Fishing Association: Environment Agency (EA) Surveys
Since 1997, all fisheries population data from sites within England and Wales have been graded by the EA using the following National Fishery Classification Scheme:

Grade Description Interpretation
A Excellent In the top 20% for a fishery of this type
B Good In the top 40% for a fishery of this type
C Fair In the middle 20% for a fishery of this type
D Fair In the bottom 40% for a fishery of this type
E Poor In the bottom 20% for a fishery of this type
F Fishless No fish of this type present


How is fish density on the Avon graded?
  • From 2002 to 2006 inclusive the site on the Avon at Avonwick Mill (now named Turtley Corn Mill) was fished between stop nets and each survey consisted of 3 runs
  • From 2007 onwards the site has been fished using no stop nets and only one run (The Environment Agency National Fish Population Database (NFPD) automatically adjusts the figures for the one-run surveys and produces the results as if they had fished the site using 3 runs between stop nets)
  • The same site is fished every year and is fished in an upstream direction using electric fishing kit producing a Pulsed Direct Current of approximately 0.3amps
The number of fish caught is expressed as the density of fish per 100 square meters -100mē. This value is then converted into a grade using the following conversion table:

A B C D E
Age Density of fish per 100 square meters -100mē
Brown/Sea Trout 0+ >38 17 to 37 8 to 16 3 to 7 <3
Brown/Sea Trout >0+ >21 12 to 20 5 to 11 2 to 4 <2
Salmon 0+ >86 45 to 85 23 to 44 9 to 22 <9
Salmon >0+ >19 10 to 18 5 to 9 3 to 4 <3
  • In the next set of tables, population density is expressed in two ways:
    • Density of fish per 100 square meters -100mē
    • and as the corresponding National Fishery Classification Scheme grade - from A through F
  • The data from three local rivers - the Avon, Erme and Yealm is presented below for comparison 
  • EA data kindly supplied by Mike Cooper and Stuart Watts, Aune Conservation Association 

Avon - Glazebrook Avonwick Mill
Year Trout Fry density Grade Trout Parr density Grade Salmon Fry density Grade Salmon Parr density Grade
2002 5.68 D 4.39 D 8.51 E 5.93 C
2003 11.87 C 12.84 B 40.12 C 8.99 C
2004 12.02 C 18.35 B 27.2 C 9.81 C
2005 8.52 C 16.19 B 10.51 D 6 C
2006 18.62 B 19.3 B 33.18 C 6.77 C
2007 11.13 C 12.11 B 33.38 C 8.51 C
2008 9.58 C 9.3 C 27.63 C 11.56 B
2009 10.27 C 10.61 C 78.03 B 11.98 B

Erme - Lower Piles
Year Trout Fry density Grade Trout Parr density Grade Salmon Fry density Grade Salmon Parr density Grade
2002 15.59 C 15.02 B 3.69 E 0.85 E
2003 13.93 C 8.47 C 1.09 E 2.73 E
2004 29.61 B 12.21 B 18.32 D 3.05 D
2005 30.63 B 12.25 B 16.44 D 6.13 C
2006 25.97 B 9.74 C 8.99 E 4.25 D
2007 20.53 B 21.38 A 4.5 E 6.75 C
2008 11.88 C 4.99 D 0.48 E 3.09 D
2009 14.20 C 13.74 B 0.93 E 4.19 D

Yealm - Potson's Wood (SX6027056630)
Year Trout Fry density Grade Trout Parr density Grade Salmon Fry density Grade Salmon Parr density Grade
2002 5.8 D 7.1 C 6.2 E 2.1 E
2003 8.1 C 14.9 B 16.9 D 3.7 D
2004 5.2 D 12.2 B 27.0 C 5.2 C
2005 2.1 E 9.8 C 32.0 C 8.5 C
2006 12.9 C 11 C 39.2 C 8.2 C
2007 1.0 E 4.1 D 40.6 C 3.7 D
2008 6.5 D 5.9 C 7.5 E 3.6 D