Bullhead · Cottus gobio

Bullhead in the River Blackwater

Largest measured bullhead: 7 cm

The largest bullhead measured in Environment Agency surveys of the River Blackwater was 7 cm, recorded at Landford on 15 September 2006.

Across 42 measured bullhead, the median measured length was 5.5 cm.

Surveyors recorded weights for 2 bullhead. The median was 0.1 oz (0.0025 kg) and the largest recorded weight was 0.1 oz (0.003 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 bullhead records across England →

Most recent observation18 September 2025Landford · 23 fish

Largest measured bullhead: 7 cm
Median length: 5.5 cm
Fish measured: 42
Survey locations: 6

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
7 cm	15 Sept 2006	Landford	101352
7 cm	15 Sept 2006	Landford	101352
6.9 cm	18 Sept 2025	Landford	179227
6.7 cm	15 Sept 2006	Landford	101352
6.6 cm	18 Sept 2025	Landford	179227
6.6 cm	15 Sept 2006	Landford	101352
6.5 cm	18 Sept 2025	Landford	179227
6.5 cm	18 Sept 2025	Landford	179227
6.5 cm	18 Sept 2025	Landford	179227
6.3 cm	18 Sept 2025	Landford	179227

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
Landford	4 Sept 2002	18 Sept 2025	14
Broadlands Fishery	20 Sept 2011	16 Sept 2025	9
Wade Bridge	16 Sept 2003	23 Jul 2018	2
Lower Bridge Farm	31 Jul 2012	31 Jul 2012	1
Upper Whinwhistle	20 Sept 2011	20 Sept 2011	1
Lower Whinwhistle	28 Jul 2011	28 Jul 2011	1

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

2002–2025

Survey records by year

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

102

203

104

105

106

007

008

009

010

311

112

113

014

015

016

017

318

219

220

221

222

223

224

225

Fish measured by surveyors

Measured length distribution

See how the 42 measured fish were spread across different length ranges.

Smallest: 2.8 cm
Lower quarter: 4.5 cm
Median: 5.5 cm
Upper quarter: 6.2 cm
Largest: 7 cm

0–99 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 2 bullhead. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.1 oz (0.002 kg)
Lower quarter: 0.1 oz (0.0022 kg)
Median: 0.1 oz (0.0025 kg)
Upper quarter: 0.1 oz (0.0028 kg)
Heaviest: 0.1 oz (0.003 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 European eel Dace Brown / sea trout Stone loach 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 →