RiverFish

Brook lamprey · Lampetra planeri

Brook lamprey in the River Ash

Largest measured brook lamprey: 16 cm

The largest brook lamprey measured in Environment Agency surveys of the River Ash was 16 cm, recorded at Watersplace Farm on 18 September 2025.

Across 127 measured brook lamprey, the median measured length was 13 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 Ash.

See brook lamprey records across England →

Most recent observation18 September 2025Watersplace Farm · 7 fish
Largest measured brook lamprey
16 cm
Median length
13 cm
Fish measured
127
Survey locations
7

Individual EA measurements

Largest measured brook lamprey

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

LengthSurvey dateSurvey locationSurvey ID
16 cm18 Sept 2025Watersplace Farm178723
16 cm9 Sept 2008Watersplace Farm114332
16 cm9 Sept 2008Watersplace Farm114332
15.8 cm4 Nov 2021Hollycross Road160898
15.6 cm9 Sept 2008Watersplace Farm114332
15.5 cm10 Oct 2017Hollycross Road151952
15.4 cm15 Sept 2011Watersplace Farm128121
15.2 cm17 Sept 2015Watersplace Farm146492
15.2 cm15 Sept 2011Watersplace Farm128121
15.2 cm15 Sept 2011Watersplace Farm128121

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

Explore the river

Where brook lamprey were found

Each point marks a survey location with at least one brook 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 brook lamprey
Watersplace Farm10 Oct 200318 Sept 202510
Wareside Fully Quantitative30 Sept 201212 Sept 20245
Hollycross Road22 Oct 20074 Nov 20216
Wareside18 Sept 201818 Sept 20181
u/s Ford Waterplace Farm19 Nov 200319 Nov 20031
Blakesware Estate13 Oct 200313 Oct 20031
Blakesware estate enhancement downstream4 Mar 20034 Mar 20031

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

2003–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 127 measured fish were spread across different length ranges.

Smallest
4.5 cm
Lower quarter
12 cm
Median
13 cm
Upper quarter
14 cm
Largest
16 cm

Lengths are direct survey measurements rather than anglers’ catches.

More fish in this river

Explore the River Ash

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

Brown / sea trout Bullhead Minnow 3-spined stickleback Stone loach Roach

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 →