RiverFish

European eel · Anguilla anguilla

European eel in the Swavesey Drain

Largest measured european eel: 75 cm

The largest european eel measured in Environment Agency surveys of the Swavesey Drain was 75 cm, recorded at Swavesey Drain (Eel Monitoring) on 16 June 2008.

Across 304 measured european eel, the median measured length was 34 cm.

Surveyors recorded weights for 298 european eel. The median was 2.8 oz (0.08 kg) and the largest recorded weight was 2 lb 10.3 oz (1.2 kg).

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

See european eel records across England →

Most recent observation20 May 2026US Webs Hole Sluice · 3 fish
Largest measured european eel
75 cm
Median length
34 cm
Fish measured
304
Survey locations
2

Individual EA measurements

Largest measured european eel

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

LengthSurvey dateSurvey locationSurvey ID
75 cm16 Jun 2008Swavesey Drain (Eel Monitoring)111309
75 cm10 May 2007Swavesey Drain (Eel Monitoring)105286
70 cm16 Jun 2008Swavesey Drain (Eel Monitoring)111309
62 cm10 May 2007Swavesey Drain (Eel Monitoring)105286
58 cm29 May 2009Swavesey Drain (Eel Monitoring)117292
55 cm16 Jun 2008Swavesey Drain (Eel Monitoring)111309
55 cm16 Jun 2008Swavesey Drain (Eel Monitoring)111309
54 cm10 May 2007Swavesey Drain (Eel Monitoring)105286
54 cm10 May 2007Swavesey Drain (Eel Monitoring)105286
53 cm29 May 2009Swavesey Drain (Eel Monitoring)117292

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

Explore the river

Where european eel were found

Each point marks a survey location with at least one european eel 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 european eel
US Webs Hole Sluice18 Apr 200520 May 20263
Swavesey Drain (Eel Monitoring)10 May 20072 May 20136

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

2005–2026

Survey records by year

Each bar shows how many survey visits recorded european eel that year.

Fish measured by surveyors

Measured length distribution

See how the 304 measured fish were spread across different length ranges.

Smallest
17 cm
Lower quarter
28 cm
Median
34 cm
Upper quarter
39 cm
Largest
75 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 298 european eel. This is a subset of the measured fish and may not represent the whole population.

Lightest
0.3 oz (0.008 kg)
Lower quarter
1.4 oz (0.0385 kg)
Median
2.8 oz (0.08 kg)
Upper quarter
4.9 oz (0.14 kg)
Heaviest
2 lb 10.3 oz (1.2 kg)

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

More fish in this river

Explore the Swavesey Drain

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

Dace Perch Roach Tench Common bream

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 →