RiverFish

Bullhead · Cottus gobio

Bullhead in the River Ash

Largest measured bullhead: 10.1 cm

The largest bullhead measured in Environment Agency surveys of the River Ash was 10.1 cm, recorded at Hollycross Road on 22 October 2007.

Across 956 measured bullhead, the median measured length was 5.5 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 Ash.

See bullhead records across England →

Most recent observation18 September 2025Watersplace Farm
Largest measured bullhead
10.1 cm
Median length
5.5 cm
Fish measured
956
Survey locations
13

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
10.1 cm22 Oct 2007Hollycross Road107928
10 cm16 Oct 2007Watersplace Farm107896
9.8 cm16 Oct 2007Watersplace Farm107896
9.6 cm16 Oct 2007Watersplace Farm107896
9.5 cm16 Oct 2007Watersplace Farm107896
9.5 cm16 Oct 2007Watersplace Farm107896
9.4 cm16 Oct 2007Watersplace Farm107896
9.3 cm4 Nov 2021Hollycross Road160898
9.3 cm16 Oct 2007Watersplace Farm107896
9.3 cm16 Oct 2007Watersplace Farm107896

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
Watersplace Farm10 Oct 200318 Sept 202514
Wareside Fully Quantitative30 Sept 201218 Sept 20258
Hollycross Road22 Oct 200719 Sept 202312
Much Hadham Fully Quantitative30 Sept 20129 Oct 20182
Wareside28 Jun 200618 Sept 20182
Easeneye Weir Removal23 Oct 200723 Oct 20071
Much Hadham30 Jun 200630 Jun 20061
Upstream Blakeswere Widford29 Jun 200629 Jun 20061
Holly cross rd/water place farm22 Jun 200622 Jun 20061
Blakesware estate enhancement downstream4 Mar 20037 Jun 20052
u/s Ford Waterplace Farm19 Nov 200319 Nov 20031
Blakesware Estate13 Oct 200313 Oct 20031
Blakesware estate enhancement upstream3 Mar 20033 Mar 20031

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

2003–2025

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 956 measured fish were spread across different length ranges.

Smallest
2.8 cm
Lower quarter
4.5 cm
Median
5.5 cm
Upper quarter
6.8 cm
Largest
10.1 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Ash

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

Brown / sea trout Minnow 3-spined stickleback Stone loach Brook lamprey Roach

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 →