RiverFish

Grayling · Thymallus thymallus

Grayling in the River Colne

Largest measured grayling: 32.2 cm

The largest grayling measured in Environment Agency surveys of the River Colne was 32.2 cm, recorded at Stafford Mills on 25 August 2015.

Across 161 measured grayling, the median measured length was 11.7 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 grayling records across England →

Most recent observation27 August 2025Lees Mill lane · 1 fish
Largest measured grayling
32.2 cm
Median length
11.7 cm
Fish measured
161
Survey locations
7

Individual EA measurements

Largest measured grayling

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

LengthSurvey dateSurvey locationSurvey ID
32.2 cm25 Aug 2015Stafford Mills146171
29.1 cm22 Jul 2013Lees Mill lane139676
27.7 cm27 Aug 2015Lees Mill lane146319
27.2 cm22 Jul 2013Stoney Battery Lane139683
27.1 cm14 Oct 2021Lees Mill lane160464
27 cm13 Aug 2015Galpham Stadium145908
26.9 cm30 Aug 2007Lees Mill lane108407
26.7 cm4 Aug 2012DS Slaithewaite Park133235
26.5 cm30 Aug 2007Lees Mill lane108407
26.2 cm30 Aug 2013Lees Mill lane138498

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

Explore the river

Where grayling were found

Each point marks a survey location with at least one grayling 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 grayling
Lees Mill lane27 Sept 200527 Aug 202513
Stafford Mills7 Sept 201025 Aug 20152
Galpham Stadium13 Aug 201513 Aug 20151
Stoney Battery Lane22 Jul 201322 Jul 20131
Slaithewaite park footbridge4 Aug 20124 Aug 20121
DS Slaithewaite Park4 Jun 20104 Aug 20122
Pollard Street23 Sept 200323 Sept 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 grayling that year.

Fish measured by surveyors

Measured length distribution

See how the 161 measured fish were spread across different length ranges.

Smallest
7 cm
Lower quarter
9.5 cm
Median
11.7 cm
Upper quarter
20.6 cm
Largest
32.2 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 3-spined stickleback Minnow Bullhead

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 →