RiverFish

Grayling · Thymallus thymallus

Grayling in the Main river sites

Largest measured grayling: 42.6 cm

The largest grayling measured in Environment Agency surveys of the Main river sites was 42.6 cm, recorded at S8 Blandford on 4 September 2012.

Across 99 measured grayling, the median measured length was 23.8 cm.

Surveyors recorded weights for 4 grayling. The median was 12 oz (0.34 kg) and the largest recorded weight was 1 lb 11.3 oz (0.773 kg).

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

See grayling records across England →

Most recent observation18 September 2025Canford School (top site S2S) · 1 fish
Largest measured grayling
42.6 cm
Median length
23.8 cm
Fish measured
99
Survey locations
15

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
42.6 cm4 Sept 2012S8 Blandford134062
41 cm8 Aug 2002S2 Upstream Eccliffe73180
40.1 cm31 Jul 2019Blandford - Stour Meadow155041
38.5 cm27 Jun 2018S3R Corfe Mullen to Cowgrove152927
37.5 cm27 Jun 2018S3R Corfe Mullen to Cowgrove152927
37.4 cm4 Sept 2012S8 Blandford134062
35.4 cm4 Sept 2012S8 Blandford134062
35.3 cm9 Aug 2010Blandford channel123333
35.1 cm4 Jun 2009S3R Corfe Mullen to Cowgrove117536
34.5 cm31 Jul 2019Blandford - Stour Meadow155041

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
Cowgrove Weir20 Sept 202218 Sept 20252
Canford School (top site S2S)17 Sept 201918 Sept 20253
Crawford Bridge16 Sept 201918 Sept 20242
S1 Gillingham17 Jul 20028 Jun 20234
Keyneston Mill16 Sept 202120 Sept 20222
Blandford - Stour Meadow13 Jun 201827 Jul 20223
Charlton Marshall Island16 Sept 202116 Sept 20211
Sturminster Marshall Island15 Sept 202115 Sept 20211
Stour at Millmore Farm1 Aug 20191 Aug 20191
S3R Corfe Mullen to Cowgrove22 Jun 200427 Jun 20184
S8 Blandford4 Sept 20124 Sept 20121
S9 Spetisbury30 May 201230 May 20121
S2 Upstream Eccliffe8 Aug 20027 Jun 20113
Blandford channel9 Aug 20109 Aug 20101
Ham Carpark23 Sept 200523 Sept 20051

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 grayling that year.

Fish measured by surveyors

Measured length distribution

See how the 99 measured fish were spread across different length ranges.

Smallest
7.5 cm
Lower quarter
18.7 cm
Median
23.8 cm
Upper quarter
28.9 cm
Largest
42.6 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 4 grayling. This is a subset of the measured fish and may not represent the whole population.

Lightest
2 oz (0.058 kg)
Lower quarter
2.7 oz (0.0775 kg)
Median
12 oz (0.34 kg)
Upper quarter
1 lb 6.6 oz (0.6402 kg)
Heaviest
1 lb 11.3 oz (0.773 kg)

These are direct individual weights recorded by Environment Agency surveyors. Combined bulk weights are not included.

More fish in this river

Explore the Main river sites

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

Minnow Bullhead European eel Dace Stone loach Chub

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 →