RiverFish

Bullhead · Cottus gobio

Bullhead in the River Colne

Largest measured bullhead: 8.5 cm

The largest bullhead measured in Environment Agency surveys of the River Colne was 8.5 cm, recorded at Lees Mill lane on 14 October 2021.

Across 49 measured bullhead, the median measured length was 4.6 cm.

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

See bullhead records across England →

Most recent observation27 August 2025Lees Mill lane
Largest measured bullhead
8.5 cm
Median length
4.6 cm
Fish measured
49
Survey locations
2

Individual EA measurements

Largest measured bullhead

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

LengthSurvey dateSurvey locationSurvey ID
8.5 cm14 Oct 2021Lees Mill lane160464
8.4 cm26 Aug 2015Clough Lea146185
8 cm14 Oct 2021Lees Mill lane160464
8 cm14 Oct 2021Lees Mill lane160464
8 cm14 Oct 2021Lees Mill lane160464
8 cm14 Oct 2021Lees Mill lane160464
8 cm14 Oct 2021Lees Mill lane160464
7.5 cm14 Oct 2021Lees Mill lane160464
7 cm14 Oct 2021Lees Mill lane160464
7 cm14 Oct 2021Lees Mill lane160464

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 surveyedFirst recordedLast recordedVisits finding bullhead
Lees Mill lane14 Oct 202127 Aug 20253
Clough Lea26 Aug 201514 Oct 20212

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

2015–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 49 measured fish were spread across different length ranges.

Smallest
3.1 cm
Lower quarter
4.3 cm
Median
4.6 cm
Upper quarter
6 cm
Largest
8.5 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Colne

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

Brown / sea trout Stone loach Grayling 3-spined stickleback 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 →