Gudgeon · Gobio gobio

Gudgeon in the Sandon Brook (Main Reaches)

Largest measured gudgeon: 15.8 cm

The largest gudgeon measured in Environment Agency surveys of the Sandon Brook (Main Reaches) was 15.8 cm, recorded at Graces Walk on 10 May 2013.

Across 763 measured gudgeon, the median measured length was 10.1 cm.

RiverFish uses Environment Agency survey measurements rather than rod-and-line angling records. These figures show fish measured during EA surveys of the Sandon Brook (Main Reaches).

See gudgeon records across England →

Most recent observation9 May 2025Boreham Bridge (Sandon Brook) · 13 fish

Largest measured gudgeon: 15.8 cm
Median length: 10.1 cm
Fish measured: 763
Survey locations: 4

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
15.8 cm	10 May 2013	Graces Walk	137520
15 cm	13 May 1986	Baddow Fruit Farm	14483
15 cm	13 May 1986	Baddow Fruit Farm	14483
14.6 cm	13 May 1986	Baddow Fruit Farm	14483
14.5 cm	13 May 1986	Baddow Fruit Farm	14483
14.3 cm	8 May 2025	Graces Walk	177233
14.2 cm	29 May 2019	Graces Walk	155997
14.2 cm	31 May 2001	Graces Walk	15599
14.2 cm	13 May 1986	Baddow Fruit Farm	14483
14.1 cm	2 May 1995	Graces Walk	14496

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
Boreham Bridge (Sandon Brook)	9 May 1986	9 May 2025	8
Graces Walk	15 May 1986	8 May 2025	9
Baddow Fruit Farm	13 May 1986	1 Jun 2001	5
Danbury Road FGS	16 May 1986	26 May 1998	4

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

1986–2025

Survey records by year

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

486

087

088

189

090

091

492

093

094

495

096

097

498

099

000

301

002

003

004

005

006

207

008

009

010

011

012

113

014

015

016

017

018

119

020

021

022

023

024

225

Fish measured by surveyors

Measured length distribution

See how the 763 measured fish were spread across different length ranges.

Smallest: 3.9 cm
Lower quarter: 9 cm
Median: 10.1 cm
Upper quarter: 11.6 cm
Largest: 15.8 cm

0–99 mm

337

100–199 mm

426

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Sandon Brook (Main Reaches)

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

Chub European eel Roach Dace Pike Minnow

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 →