Upper Stour EA Fish Survey 2012

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Fisheries Report for the Upper River Stour 2012


Twelve sites were fished using electric fishing gear between 4th September and 5th October 2012.

Results are reported here using fish greater than (>) 99mm as electro-fishing has been shown to be inefficient below this band.

Fourteen species and three hybrid types were identified during the survey. 3545 fish (>99mm) were caught.

The average density (number of fish in a given area) of all species (>99mm) over all sites rose from 11.56 Ind./100m2 in 2009 to 18.40 Ind./100m2 in 2012, an increase of 59%.

Total average standing crop (weight of fish in a given area) also rose from 1572.39 g/100m2 in 2009 to 1772.04 g/100m2 in 2012, an increase of 13%. Density Composition (%) 5%

Standing Crop Composition (%)

3%

2%

12%

22%

0%

Chub 8%

Dace

39%

European Eel 3%

5%

Perch

1%

Pike Roach Other

12%

69%

19%

Density of fish species (>99mm) on the Upper Stour 14

Density (ind./1000m2)

12 10

Chub

Dace

8

Eels Perch

6

Pike Roach

4 2 0 1985

1988

1991

1994

1997

2000

2003

2006

2009

2012

Mean


Roach were the most common fish >99mm with a 69% share of the population for the sites surveyed (followed by dace 12%).

Since 2009 roach density has doubled in size from 6.3 individuals per 100m 2 to 12.7 individuals per 100m2.This is the highest density recorded for roach on the Upper Stour since surveying began. Roach density has therefore increased by 1.6% per year since 1985.

Roach fortune coincides with a 75% reduction in pike numbers from 2.3 individuals per 100m2 to 0.6 individuals per 100m2.

Eel density has also declined, whilst dace and perch numbers have increased above the long term mean. Chub numbers remain relatively constant.

Smaller fish, under 99mm, are not included in these graphs as they are not accurately collected. Therefore this report does not reflect recruitment numbers.

Standing crop of fish species (99mm) on the Upper Stour 900 800

Standing crop (g/100m 2)

700 Chub

600

Dace

500

Eels

400

Perch Pike

300

Roach

200 100 0 1985

1988

1991

1994

1997

2000

2003

2006

2009

2012

Mean

Chub numbers may only account for 3% of the total density of fish encountered in 2012, but the species holds a 22% share of the standing crop. In general terms, those individuals sampled were generally large specimens. Since 1985 chub standing crop has increased by 4.6% per year.

Unsurprisingly, along with the increase in roach density, roach standing crop has also increased and is now above the long term average. Conversely pike standing crop has fallen below the long term mean after a drop in density.

Both dace and eel standing crops are below their respective long term averages whilst perch have seen a 70% increase since 2009 to record a value of 211g/100m2, placing them above their long term average.


The largest individual (mm) and species population estimate (>99mm) are recorded for chub, dace, perch, pike and roach at site level in the table below. CHUB Size (mm) Liston Mill Bush Boake Allen Pentlow Mill Bower Hall Rats Castle Clare Mill Mill Farm Clare Stoke By Clare Baythorne End Wixoe P.S. Kedington Radial Gate Great Thurlow

DACE

PERCH

PIKE

ROACH

No. 7

Largest 498

No. 70

Largest 209

No. 18

Largest 246

No. 14

Largest 707

No. 480

Largest 253

14

420

55

204

11

208

14

448

85

214

13 11 21 3 14 3 4

525 500 513 509 478 448 481

27 9 73 -

97 189 233 181 86 72

8 2 12 6 22 58 41 74

298 241 253 374 382 307 326 402

5 9 14 12 28 18 11 18

587 717 427 845 801 671 698 614

4 8 48 293 333 167 80 703

173 144 160 268 293 213 270 237

10

458

193

237

21

221

-

-

21

219

30

422

-

-

22

194

-

-

136

242

The largest fish from the surveys were: 

a 525mm (4.0lb) chub at Pentlow Mill.

a 237mm (0.4lb) dace at Kedington Radial Gate.

a 402mm (3.2lb) perch at Wixoe Pumping Station.

a 845mm (12.7lb) pike at Clare Mill.

a 293mm (lb) roach at Mill farm Clare.

Before you go fishing don’t forget   

You must have an Environment Agency rod licence before you fish and permission from the fishery owner. You must comply with the fisheries byelaws. The course fish close season (15th March – 15th June inclusive) applies to all rivers, streams and drains in England and Wales, but not to most stillwaters. Stillwater fishery owners can have their own close season and rules, so please check with them before setting out.

Reporting illegal fishing If you see any fishing, netting or trapping you think may be illegal, please don’t tackle it yourself. Call us on 0800 80 70 60 and tell us:  Exactly where the alleged offence is taking place  What’s happening  How many people are involved and their descriptions  The registration numbers of any vehicles involved.


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