RiverFish

Grayling · Thymallus thymallus

Grayling in the River Dun

Largest measured grayling: 42.9 cm

The largest grayling measured in Environment Agency surveys of the River Dun was 42.9 cm, recorded at Freemans Marsh on 22 March 2006.

Across 225 measured grayling, the median measured length was 17 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 Dun.

See grayling records across England →

Most recent observation16 October 2025Beat 9 - Eel · 4 fish
Largest measured grayling
42.9 cm
Median length
17 cm
Fish measured
225
Survey locations
3

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
42.9 cm22 Mar 2006Freemans Marsh90430
42.8 cm22 Mar 2006Freemans Marsh90430
42 cm15 Oct 2024Beat 9 - Eel167915
42 cm22 Mar 2006Freemans Marsh90430
41.3 cm26 Aug 2010Freemans Marsh- DS gauging weir125275
40.9 cm22 Mar 2006Freemans Marsh90430
40.8 cm26 Aug 2010Freemans Marsh- DS gauging weir125275
39.9 cm22 Mar 2006Freemans Marsh90430
39.7 cm27 Mar 2007Freemans Marsh104912
39.5 cm15 Oct 2024Beat 9 - Eel167915

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
Beat 9 - Eel17 Oct 202316 Oct 20253
Freemans Marsh22 Mar 200620 Mar 20255
Freemans Marsh- DS gauging weir26 Aug 201026 Aug 20101

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

2006–2025

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 225 measured fish were spread across different length ranges.

Smallest
8 cm
Lower quarter
9.9 cm
Median
17 cm
Upper quarter
26 cm
Largest
42.9 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Dun

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

Brown / sea trout Bullhead Gudgeon Dace Pike 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 →