Bullhead · Cottus gobio

Bullhead in the Sandon Brook (Main Reaches)

Largest measured bullhead: 9.5 cm

The largest bullhead measured in Environment Agency surveys of the Sandon Brook (Main Reaches) was 9.5 cm, recorded at Baddow Fruit Farm on 7 May 1992.

Across 155 measured bullhead, the median measured length was 6.2 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 bullhead records across England →

Most recent observation9 May 2025Boreham Bridge (Sandon Brook) · 4 fish

Largest measured bullhead: 9.5 cm
Median length: 6.2 cm
Fish measured: 155
Survey locations: 4

Individual EA measurements

Largest measured bullhead

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
9.5 cm	7 May 1992	Baddow Fruit Farm	14491
9 cm	8 May 1992	Graces Walk	14492
8.8 cm	7 May 1992	Baddow Fruit Farm	14491
8.7 cm	8 May 2025	Graces Walk	177233
8.4 cm	8 May 2025	Graces Walk	177233
8.4 cm	29 May 2019	Graces Walk	155997
8.4 cm	9 May 2007	Graces Walk	105385
8.3 cm	10 May 2013	Graces Walk	137520
8.3 cm	8 May 1992	Graces Walk	14492
8.1 cm	8 May 2025	Graces Walk	177233

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

Explore the river

Where bullhead were found

Each point marks a survey location with at least one bullhead 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 bullhead
Boreham Bridge (Sandon Brook)	9 May 2013	9 May 2025	2
Graces Walk	8 May 1992	8 May 2025	8
Danbury Road FGS	29 May 2001	29 May 2001	1
Baddow Fruit Farm	13 May 1986	7 May 1992	2

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 bullhead that year.

186

087

088

089

090

091

292

093

094

195

096

097

198

099

000

201

002

003

004

005

006

107

008

009

010

011

012

213

014

015

016

017

018

119

020

021

022

023

024

225

Fish measured by surveyors

Measured length distribution

See how the 155 measured fish were spread across different length ranges.

Smallest: 4.3 cm
Lower quarter: 5.7 cm
Median: 6.2 cm
Upper quarter: 6.9 cm
Largest: 9.5 cm

0–99 mm

155

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 Gudgeon

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 →