RiverFish

Flounder · Platichthys flesus

Flounder in the Main River Avon Sites

Largest measured flounder: 22.2 cm

The largest flounder measured in Environment Agency surveys of the Main River Avon Sites was 22.2 cm, recorded at Upstream Knap Mill (Sp) on 24 July 2013.

Across 6 measured flounder, the median measured length was 18.6 cm.

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

See flounder records across England →

Most recent observation9 August 2022Upstream Knap Mill (Sp) · 3 fish
Largest measured flounder
22.2 cm
Median length
18.6 cm
Fish measured
6
Survey locations
2

Individual EA measurements

Largest measured flounder

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

LengthSurvey dateSurvey locationSurvey ID
22.2 cm24 Jul 2013Upstream Knap Mill (Sp)137361
19.9 cm9 Aug 2022Upstream Knap Mill (Sp)161286
19 cm24 Jul 2013Upstream Hatchbridge (Dip)137354
18.3 cm24 Jul 2013Upstream Hatchbridge (Dip)137354
7.1 cm9 Aug 2022Upstream Knap Mill (Sp)161286
6.1 cm9 Aug 2022Upstream Knap Mill (Sp)161286

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

Explore the river

Where flounder were found

Each point marks a survey location with at least one flounder 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 flounder
Upstream Knap Mill (Sp)22 Aug 20119 Aug 20223
Upstream Hatchbridge (Dip)23 Aug 200024 Jul 20132

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

2000–2022

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 6 measured fish were spread across different length ranges.

Smallest
6.1 cm
Lower quarter
9.9 cm
Median
18.7 cm
Upper quarter
19.7 cm
Largest
22.2 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Main River Avon Sites

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

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

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 →