Gudgeon · Gobio gobio

Gudgeon in the River Blackwater

Largest measured gudgeon: 17.8 cm

The largest gudgeon measured in Environment Agency surveys of the River Blackwater was 17.8 cm, recorded at Aldershot on 9 April 2003.

Across 1,409 measured gudgeon, the median measured length was 11.9 cm.

Surveyors recorded weights for 15 gudgeon. The median was 0.7 oz (0.019 kg) and the largest recorded weight was 0.9 oz (0.026 kg).

RiverFish uses Environment Agency survey measurements rather than rod-and-line angling records. These figures show fish measured during EA surveys of the River Blackwater.

See gudgeon records across England →

Most recent observation6 May 2026Coleford Bridge · 4 fish

Largest measured gudgeon: 17.8 cm
Median length: 11.9 cm
Fish measured: 1,409
Survey locations: 23

Individual EA measurements

Largest measured gudgeon

The largest individual measurements in this river and species dataset. Equal measurements are retained as separate surveyed fish.

Length	Survey date	Survey location	Survey ID
17.8 cm	9 Apr 2003	Aldershot	75806
16.6 cm	5 Apr 2007	Hawley Meadows	105015
16.2 cm	7 Apr 2004	Hawley Meadows	79771
15.9 cm	9 Apr 2003	Aldershot	75806
15.9 cm	3 Apr 2003	Church Farm	75793
15.9 cm	1 Apr 2003	Eversley Cross	75788
15.7 cm	7 Apr 2004	Hawley Meadows	79771
15.5 cm	11 Apr 2007	Eversley Cross	105034
15.5 cm	9 Apr 2002	Eversley Cross	50341
15.5 cm	9 Apr 2002	Hawley Meadows	50240

Lengths are direct survey measurements. RiverFish does not estimate fish weights from length.

Explore the river

Where gudgeon were found

Each point marks a survey location with at least one gudgeon record.

Choose a point on the map to see what was recorded there.

Map points are approximate and don’t show fishing access. Check local permissions before visiting.

Place surveyed	First recorded	Last recorded	Visits finding gudgeon
Coleford Bridge	21 Mar 2003	6 May 2026	5
Hawley Meadows	5 Dec 1990	10 Apr 2025	17
Riseley	4 Apr 2002	8 Apr 2025	13
Manor Farm Nature reserve	8 Apr 2025	8 Apr 2025	1
Downstream Riseley	23 Sept 1985	18 May 2016	3
Aldershot Park	18 Apr 2013	16 May 2016	2
Eversley Cross	7 Dec 1990	15 Apr 2010	8
Hollybush Lane	16 Apr 2003	16 Apr 2003	1
Aldershot	9 Apr 2003	9 Apr 2003	1
Church Farm	3 Apr 2003	3 Apr 2003	1
Owlsmoor	10 Oct 1985	27 Mar 2003	3
Greenacres	27 Sept 1985	29 Jan 1991	2
Downstream Sandhurst Lane	18 Dec 1990	18 Dec 1990	1
Upstream Cove Brook	3 Dec 1990	3 Dec 1990	1
Upstream A325 Frimley	30 Nov 1990	30 Nov 1990	1
Grove Farm	23 Nov 1990	23 Nov 1990	1
0.5km Upstream Coleford bridge	17 Oct 1985	17 Oct 1985	1
Upstream Loddon	2 Oct 1985	2 Oct 1985	1
Eversley Trout Fishery	30 Sept 1985	30 Sept 1985	1
Downstream Greenacres	27 Sept 1985	27 Sept 1985	1
RAE Riseley	24 Sept 1985	24 Sept 1985	1
Downstream Whitewater confluence	24 Sept 1985	24 Sept 1985	1
300m Upstream Swallowfield G/S	23 Sept 1985	23 Sept 1985	1

Choose a point or table row to see the location. More survey visits can mean more records, but not necessarily more fish.

1985–2026

Survey records by year

Each bar shows how many survey visits recorded gudgeon that year.

1085

086

087

088

089

790

291

092

093

094

095

096

097

098

099

000

101

302

803

304

305

306

307

208

209

410

011

112

313

014

015

516

017

018

219

020

021

222

023

024

325

126

Fish measured by surveyors

Measured length distribution

See how the 1,409 measured fish were spread across different length ranges.

Smallest: 4 cm
Lower quarter: 10.5 cm
Median: 11.9 cm
Upper quarter: 13.1 cm
Largest: 17.8 cm

0–99 mm

245

100–199 mm

1164

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 15 gudgeon. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.5 oz (0.013 kg)
Lower quarter: 0.6 oz (0.017 kg)
Median: 0.7 oz (0.019 kg)
Upper quarter: 0.7 oz (0.0205 kg)
Heaviest: 0.9 oz (0.026 kg)

These are direct individual weights recorded by Environment Agency surveyors. Combined bulk weights are not included.

More fish in this river

Explore the River Blackwater

Compare other species with enough survey and measurement data for a detailed page.

Roach Chub Pike Dace Perch Tench

Before you fish

Good to know

These are past survey records, so the fish present today may be different. Map points are approximate—check local access, permissions and fishing rules before visiting.

Learn how RiverFish uses the data →