RiverFish

Grayling · Thymallus thymallus

Grayling in the River Main Tamar

Largest measured grayling: 40 cm

The largest grayling measured in Environment Agency surveys of the River Main Tamar was 40 cm, recorded at Tamarstone on 7 July 2023.

Across 175 measured grayling, the median measured length was 9.1 cm.

Surveyors recorded weights for 19 grayling. The median was 8.5 oz (0.24 kg) and the largest recorded weight was 1 lb 3.4 oz (0.55 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 Main Tamar.

See grayling records across England →

Most recent observation6 August 2025Tamarstone · 6 fish
Largest measured grayling
40 cm
Median length
9.1 cm
Fish measured
175
Survey locations
22

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
40 cm7 Jul 2023Tamarstone162764
34.2 cm4 Dec 2018Gunnislake Weir Index River Fish Trap159841
32.6 cm13 Nov 2018Gunnislake Weir Index River Fish Trap159836
32.3 cm15 Nov 2018Gunnislake Weir Index River Fish Trap159838
30.7 cm24 Jul 2017Gunnislake Weir Index River Fish Trap159693
29.8 cm26 Jul 2017Gunnislake Weir Index River Fish Trap159694
29.7 cm4 May 2012Gunnislake Weir Index River Fish Trap159090
29.5 cm4 May 2012Gunnislake Weir Index River Fish Trap159090
28.5 cm21 May 2018Gunnislake Weir Index River Fish Trap159744
28.2 cm4 May 2018Gunnislake Weir Index River Fish Trap159738

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
Tamarstone29 Jun 20106 Aug 20258
u/s Polson Bridge12 Jul 20045 Sept 20232
Gordonhill Plantation23 Aug 202323 Aug 20231
u/s North Tamerton2 Sept 199323 Aug 202210
Southcombe15 Sept 199619 Aug 20225
Gravel2 Jul 200419 Aug 20223
Bridgerule15 Jul 20161 Aug 20222
Gunnislake Weir Index River Fish Trap4 May 20124 Dec 201812
Wishworthy16 Sept 199615 Aug 20184
Luffincott17 Sept 199615 Aug 20184
d/s Netherbridge13 Jul 200419 Jul 20184
Dexbeer23 Aug 201623 Aug 20161
Tamartown1 Aug 199010 Aug 20164
u/s Lamerhooe Ford9 Jul 20049 Aug 20102
Tetcott Spawning Bed 225 Sept 200625 Sept 20061
North Tamerton20 Aug 20035 Aug 20052
Boyton19 Aug 199330 Jul 20043
Lawhitton13 Jul 200413 Jul 20041
Bridgetown10 Sept 199613 Jul 20042
Leighwood Waterfall2 Jul 20042 Jul 20041
u/s North Tamerton (lower riffle)2 Sept 19932 Sept 19931
d/s North Tamerton (upper riffle)2 Sept 19932 Sept 19931

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

1990–2025

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 175 measured fish were spread across different length ranges.

Smallest
1.9 cm
Lower quarter
8.1 cm
Median
9.1 cm
Upper quarter
10.8 cm
Largest
40 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 19 grayling. This is a subset of the measured fish and may not represent the whole population.

Lightest
0.4 oz (0.01 kg)
Lower quarter
3.2 oz (0.09 kg)
Median
8.5 oz (0.24 kg)
Upper quarter
15.2 oz (0.43 kg)
Heaviest
1 lb 3.4 oz (0.55 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 Main Tamar

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

Bullhead Stone loach Atlantic salmon Brown / sea trout Minnow European eel

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 →