Flounder · Platichthys flesus

Flounder in the River Black Sewer

Largest measured flounder: 35.5 cm

The largest flounder measured in Environment Agency surveys of the River Black Sewer was 35.5 cm, recorded at Kings Barn Farm, u/s STW on 29 July 2003.

Across 547 measured flounder, the median measured length was 12 cm.

Surveyors recorded weights for 515 flounder. The median was 0.7 oz (0.02 kg) and the largest recorded weight was 12.9 oz (0.367 kg).

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

See flounder records across England →

Most recent observation3 September 2012Kings Barn Farm, d/s STW · 4 fish

Largest measured flounder: 35.5 cm
Median length: 12 cm
Fish measured: 547
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.

Length	Survey date	Survey location	Survey ID
35.5 cm	29 Jul 2003	Kings Barn Farm, u/s STW	76614
30.3 cm	29 Jul 2003	Kings Barn Farm, u/s STW	76614
28.6 cm	16 Jul 2004	Kings Barn Farm, d/s STW	80836
28.4 cm	27 Aug 2002	Kings Barn Farm, u/s STW	72287
27.6 cm	3 Sept 2012	Kings Barn Farm, d/s STW	133875
26.7 cm	29 Jul 2003	Kings Barn Farm, u/s STW	76614
26.6 cm	27 Aug 2002	Kings Barn Farm, u/s STW	72287
26.5 cm	27 Aug 2002	Kings Barn Farm, u/s STW	72287
26 cm	29 Jul 2003	Kings Barn Farm, u/s STW	76614
25.4 cm	29 Jul 2003	Kings Barn Farm, u/s STW	76614

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 surveyed	First recorded	Last recorded	Visits finding flounder
Kings Barn Farm, d/s STW	27 Aug 2002	3 Sept 2012	10
Kings Barn Farm, u/s STW	6 May 1998	25 Jul 2008	8

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

1998–2012

Survey records by year

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

198

099

000

001

202

203

204

205

206

207

208

109

110

011

112

Fish measured by surveyors

Measured length distribution

See how the 547 measured fish were spread across different length ranges.

Smallest: 3.9 cm
Lower quarter: 7.1 cm
Median: 12 cm
Upper quarter: 16 cm
Largest: 35.5 cm

0–99 mm

232

100–199 mm

250

200–299 mm

300–399 mm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 515 flounder. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0 oz (0.001 kg)
Lower quarter: 0.2 oz (0.005 kg)
Median: 0.7 oz (0.02 kg)
Upper quarter: 1.7 oz (0.0495 kg)
Heaviest: 12.9 oz (0.367 kg)

These are direct individual weights recorded by Environment Agency surveyors. Combined bulk weights are not included.

More fish in this river

Explore the River Black Sewer

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

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