RiverFish

River lamprey · Lampetra fluviatilis

River lamprey in the River Keer

Largest measured river lamprey: 33.5 cm

The largest river lamprey measured in Environment Agency surveys of the River Keer was 33.5 cm, recorded at High Keer Bridge at Kellet Lane on 30 September 2025.

Across 17 measured river lamprey, the median measured length was 12 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 Keer.

See river lamprey records across England →

Most recent observation30 September 2025High Keer Bridge at Kellet Lane · 2 fish
Largest measured river lamprey
33.5 cm
Median length
12 cm
Fish measured
17
Survey locations
3

Individual EA measurements

Largest measured river lamprey

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

LengthSurvey dateSurvey locationSurvey ID
33.5 cm30 Sept 2025High Keer Bridge at Kellet Lane180296
18.8 cm18 Sept 2017High Keer Bridge at Kellet Lane151816
18 cm18 Sept 2017High Keer Bridge at Kellet Lane151816
16 cm18 Sept 2017High Keer Bridge at Kellet Lane151816
14 cm13 Aug 2019Downstream Keer West Bridge155236
14 cm18 Sept 2017High Keer Bridge at Kellet Lane151816
14 cm16 Aug 2010Cinder Hill Farm123469
12.5 cm13 Aug 2019Downstream Keer West Bridge155236
12 cm16 Aug 2010Cinder Hill Farm123469
12 cm16 Aug 2010Cinder Hill Farm123469

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

Explore the river

Where river lamprey were found

Each point marks a survey location with at least one river lamprey 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 river lamprey
High Keer Bridge at Kellet Lane18 Sept 201730 Sept 20253
Downstream Keer West Bridge13 Aug 201913 Aug 20191
Cinder Hill Farm16 Aug 201016 Aug 20101

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

2010–2025

Survey records by year

Each bar shows how many survey visits recorded river lamprey that year.

Fish measured by surveyors

Measured length distribution

See how the 17 measured fish were spread across different length ranges.

Smallest
7.5 cm
Lower quarter
10 cm
Median
12 cm
Upper quarter
14 cm
Largest
33.5 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Keer

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

Brown / sea trout European eel Atlantic salmon Brook lamprey

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 →