RiverFish

Flounder · Platichthys flesus

Flounder in the River Blyth

Largest measured flounder: 25.2 cm

The largest flounder measured in Environment Agency surveys of the River Blyth was 25.2 cm, recorded at River Blyth at Humford Mill on 2 August 2010.

Across 31 measured flounder, the median measured length was 16 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 Blyth.

See flounder records across England →

Most recent observation24 July 2024River Blyth at Humford Mill · 7 fish
Largest measured flounder
25.2 cm
Median length
16 cm
Fish measured
31
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
25.2 cm2 Aug 2010River Blyth at Humford Mill124927
24.5 cm26 Jul 2013River Blyth at Humford Mill137455
23.2 cm27 Jun 2005River Blyth at Humsford (c)89246
23 cm28 Jun 2016River Blyth at Humford Mill148313
23 cm27 Jun 2005River Blyth at Humsford (c)89246
22 cm26 Jul 2013River Blyth at Humford Mill137455
20.1 cm2 Aug 2010River Blyth at Humford Mill124927
20 cm17 Aug 2007River Blyth at Humford Mill107236
19.7 cm27 Jun 2005River Blyth at Humsford (c)89246
19 cm27 Jun 2005River Blyth at Humsford (c)89246

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
River Blyth at Humford Mill17 Aug 200724 Jul 20247
River Blyth at Humsford (c)27 Jun 200527 Jun 20051

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

2005–2024

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 31 measured fish were spread across different length ranges.

Smallest
5.5 cm
Lower quarter
13.3 cm
Median
16 cm
Upper quarter
19.9 cm
Largest
25.2 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Blyth

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

Stone loach Brown / sea trout Minnow 3-spined stickleback European eel 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 →