Brown / sea trout · Salmo trutta

Brown / sea trout in the River Monnow

Largest measured brown / sea trout: 38 cm

The largest brown / sea trout measured in Environment Agency surveys of the River Monnow was 38 cm, recorded at W055 on 11 August 1993.

Across 1,115 measured brown / sea trout, the median measured length was 9.2 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 Monnow.

See brown / sea trout records across England →

Most recent observation13 August 2025Llanveynoe · 13 fish

Largest measured brown / sea trout: 38 cm
Median length: 9.2 cm
Fish measured: 1,115
Survey locations: 9

Individual EA measurements

Largest measured brown / sea trout

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
38 cm	11 Aug 1993	W055	89380
31 cm	28 Aug 1999	W055	80488
31 cm	11 Aug 1993	Clodock	89372
31 cm	11 Aug 1993	Clodock	89372
31 cm	11 Aug 1993	Clodock	89372
31 cm	30 Jul 1991	W055	89837
30.1 cm	5 Sept 2014	Llanveynoe	142919
30 cm	22 Aug 2019	Clodock	155789
30 cm	27 Jul 2003	Clodock	76899
30 cm	11 Aug 1993	Clodock	89372

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

Explore the river

Where brown / sea trout were found

Each point marks a survey location with at least one brown / sea trout 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 brown / sea trout
W055	11 Jul 1989	13 Aug 2025	10
Llanveynoe	13 Aug 1987	13 Aug 2025	21
Clodock	11 Jul 1989	5 Aug 2025	11
W059J	30 Sept 2002	16 Sept 2003	2
W059H	21 Sept 2000	16 Sept 2003	3
W059G	21 Sept 2000	16 Sept 2003	3
W059F	22 Sept 2000	16 Sept 2003	3
W098r	20 Jul 1997	8 Sept 1999	2
W098p	30 Jul 1997	4 Sept 1999	2

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

1987–2025

Survey records by year

Each bar shows how many survey visits recorded brown / sea trout that year.

187

188

389

290

391

292

293

194

295

096

597

098

599

300

001

402

503

004

005

006

107

208

109

110

111

112

213

114

115

016

117

018

319

020

021

022

023

024

325

Fish measured by surveyors

Measured length distribution

See how the 1,115 measured fish were spread across different length ranges.

Smallest: 3 cm
Lower quarter: 7 cm
Median: 9.2 cm
Upper quarter: 16.3 cm
Largest: 38 cm

0–99 mm

587

100–199 mm

353

200–299 mm

164

300–399 mm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Monnow

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

Bullhead European eel Stone loach Minnow Grayling

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 →