RiverFish

Flounder · Platichthys flesus

Flounder in the Streams to Humber

Largest measured flounder: 34.6 cm

The largest flounder measured in Environment Agency surveys of the Streams to Humber was 34.6 cm, recorded at Sand Bridge, Mires Beck, nr Ellerker FOULNES4 on 10 October 2002.

Across 354 measured flounder, the median measured length was 7.2 cm.

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

See flounder records across England →

Most recent observation2 June 2025Sand Bridge, Mires Beck, nr Ellerker FOULNES4 · 3 fish
Largest measured flounder
34.6 cm
Median length
7.2 cm
Fish measured
354
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
34.6 cm10 Oct 2002Sand Bridge, Mires Beck, nr Ellerker FOULNES472485
34.5 cm10 Oct 2002Sand Bridge, Mires Beck, nr Ellerker FOULNES472485
31.4 cm24 Oct 2006Sand Bridge, Mires Beck, nr Ellerker FOULNES4102400
31.3 cm26 Aug 2010Sand Bridge, Mires Beck, nr Ellerker FOULNES4124073
31.2 cm24 Oct 2006Sand Bridge, Mires Beck, nr Ellerker FOULNES4102400
30.2 cm10 Oct 2002Sand Bridge, Mires Beck, nr Ellerker FOULNES472485
29.2 cm25 Sept 2005Sand Bridge, Mires Beck, nr Ellerker FOULNES487756
28.6 cm10 Oct 2002Sand Bridge, Mires Beck, nr Ellerker FOULNES472485
28.5 cm16 Oct 2007Sand Bridge, Mires Beck, nr Ellerker FOULNES4108651
28 cm26 Aug 2010Sand Bridge, Mires Beck, nr Ellerker FOULNES4124073

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
Sand Bridge, Mires Beck, nr Ellerker FOULNES410 Oct 20022 Jun 202514
Pool Beck8 Jun 20118 Jun 20111

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 flounder that year.

Fish measured by surveyors

Measured length distribution

See how the 354 measured fish were spread across different length ranges.

Smallest
3.1 cm
Lower quarter
5.9 cm
Median
7.3 cm
Upper quarter
14.2 cm
Largest
34.6 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the Streams to Humber

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

European eel Stone loach 3-spined stickleback Roach Brown / sea trout Bullhead

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 →