Grayling · Thymallus thymallus

Grayling in the Great Eau FMU

Largest measured grayling: 34.5 cm

The largest grayling measured in Environment Agency surveys of the Great Eau FMU was 34.5 cm, recorded at Claythorpe Gauging Station on 1 June 2022.

Across 101 measured grayling, the median measured length was 23.6 cm.

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

See grayling records across England →

Most recent observation1 June 2022Claythorpe Gauging Station · 13 fish

Largest measured grayling: 34.5 cm
Median length: 23.6 cm
Fish measured: 101
Survey locations: 5

Individual EA measurements

Largest measured grayling

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

Length	Survey date	Survey location	Survey ID
34.5 cm	1 Jun 2022	Claythorpe Gauging Station	160992
33.8 cm	29 Sept 1995	Claythorpe Gauging Station	58101
33 cm	1 Jun 2022	Claythorpe Gauging Station	160992
32.5 cm	1 Jun 2022	Claythorpe Gauging Station	160992
31 cm	1 Jun 2022	Claythorpe Gauging Station	160992
31 cm	1 Jun 2022	Claythorpe Gauging Station	160992
30.8 cm	18 Aug 1986	Belleau Spring	57754
30.6 cm	18 Aug 1986	Belleau Spring	57754
30.5 cm	29 Sept 1995	Withern Road Bridge	58115
30 cm	1 Jun 2022	Claythorpe Gauging Station	160992

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 surveyed	First recorded	Last recorded	Visits finding grayling
Claythorpe Gauging Station	18 Oct 1989	1 Jun 2022	7
Withern Road Bridge	9 Sept 1994	29 Sept 1995	2
Gayton Le Marsh	12 Sept 1994	12 Sept 1994	1
Woods Farm	18 Aug 1986	18 Aug 1986	1
Belleau Spring	18 Aug 1986	18 Aug 1986	1

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

1986–2022

Survey records by year

Each bar shows how many survey visits recorded grayling that year.

286

087

088

189

090

091

192

093

394

395

096

097

098

099

000

001

002

003

004

005

006

007

008

109

010

011

012

013

014

015

016

017

018

019

020

021

122

Fish measured by surveyors

Measured length distribution

See how the 101 measured fish were spread across different length ranges.

Smallest: 12.6 cm
Lower quarter: 20.8 cm
Median: 23.6 cm
Upper quarter: 25.6 cm
Largest: 34.5 cm

100–199 mm

200–299 mm

300–399 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Great Eau FMU

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

European eel 3-spined stickleback Stone loach Roach Pike Dace

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 →