Flounder · Platichthys flesus

Flounder in the River Mardyke

Largest measured flounder: 36.5 cm

The largest flounder measured in Environment Agency surveys of the River Mardyke was 36.5 cm, recorded at War Department Sluice on 21 February 1989.

Across 21 measured flounder, the median measured length was 12.8 cm.

Surveyors recorded weights for 3 flounder. The median was 0.2 oz (0.007 kg) and the largest recorded weight was 15.9 oz (0.45 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 Mardyke.

See flounder records across England →

Most recent observation18 May 2007Circus Tavern · 1 fish

Largest measured flounder: 36.5 cm
Median length: 12.8 cm
Fish measured: 21
Survey locations: 5

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
36.5 cm	21 Feb 1989	War Department Sluice	14709
24 cm	26 Sept 2001	14 Arches Bridge	20060
23.1 cm	26 Sept 2001	14 Arches Bridge	20060
22.2 cm	24 Sept 2001	North Stifford	20122
21.8 cm	26 Sept 2001	14 Arches Bridge	20060
21 cm	26 Sept 2001	14 Arches Bridge	20060
15.3 cm	7 Apr 1995	War Department Sluice	14721
14.1 cm	8 Apr 1992	War Department Sluice	14715
13.6 cm	7 Apr 1995	War Department Sluice	14721
13 cm	18 May 2007	Circus Tavern	105366

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
Circus Tavern	20 Feb 1989	18 May 2007	2
M25-A13	17 May 2007	17 May 2007	1
14 Arches Bridge	26 Sept 2001	26 Sept 2001	1
North Stifford	24 Sept 2001	24 Sept 2001	1
War Department Sluice	16 Apr 1986	7 Apr 1995	4

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

1986–2007

Survey records by year

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

186

087

088

289

090

091

192

093

094

195

096

097

098

099

000

201

002

003

004

005

006

207

Fish measured by surveyors

Measured length distribution

See how the 21 measured fish were spread across different length ranges.

Smallest: 6.1 cm
Lower quarter: 11.2 cm
Median: 12.8 cm
Upper quarter: 21 cm
Largest: 36.5 cm

0–99 mm

100–199 mm

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 3 flounder. This is a subset of the measured fish and may not represent the whole population.

Lightest: 0.2 oz (0.005 kg)
Lower quarter: 0.2 oz (0.006 kg)
Median: 0.2 oz (0.007 kg)
Upper quarter: 8.1 oz (0.2285 kg)
Heaviest: 15.9 oz (0.45 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 Mardyke

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

European eel 3-spined stickleback Roach Rudd Tench Common carp

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 →