RiverFish

Roach · Rutilus rutilus

Roach in the Main river sites

Largest measured roach: 37.8 cm

The largest roach measured in Environment Agency surveys of the Main river sites was 37.8 cm, recorded at S4 St Mary's Marnhull on 13 June 2006.

Across 3,669 measured roach, the median measured length was 14.4 cm.

Surveyors recorded weights for 115 roach. The median was 6.1 oz (0.173 kg) and the largest recorded weight was 1 lb 12.2 oz (0.8 kg).

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

See roach records across England →

Most recent observation18 September 2025Muscliffe- Kingfisher Barn Visitor Centre · 3 fish
Largest measured roach
37.8 cm
Median length
14.4 cm
Fish measured
3,669
Survey locations
32

Individual EA measurements

Largest measured roach

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

LengthSurvey dateSurvey locationSurvey ID
37.8 cm13 Jun 2006S4 St Mary's Marnhull99664
36.4 cm7 Jun 2007S4R Dudsbury to Merritown105485
35.6 cm24 May 2005S3R Corfe Mullen to Cowgrove84587
34.8 cm30 May 2012S10 White Mill131708
34.5 cm24 Jul 2002S4 St Mary's Marnhull73181
34.5 cm17 Jul 2002S1 Gillingham73173
34.4 cm12 Jun 2007S2 Upstream Eccliffe105618
34 cm17 Jul 2002S1 Gillingham73173
34 cm17 Jul 2002S1 Gillingham73173
33.9 cm24 May 2005S3R Corfe Mullen to Cowgrove84587

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

Explore the river

Where roach were found

Each point marks a survey location with at least one roach 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 roach
Muscliffe- Kingfisher Barn Visitor Centre15 Oct 202118 Sept 20255
Durweston Downstream of footbridge18 Sept 202316 Sept 20252
Kinson13 Sept 200719 Sept 20235
S1 Gillingham17 Jul 20028 Jun 202316
Blandford - Stour Meadow13 Jun 201827 Jul 20223
Upstream Haywards Bridge16 Sept 202116 Sept 20211
S2 Upstream Eccliffe8 Aug 20026 Jun 201913
S7 Durweston8 Jun 201130 May 20198
S5 Strangeways5 Aug 200223 May 201912
Longham Bridge5 Sept 201223 Aug 20182
S3R Corfe Mullen to Cowgrove22 Jun 200427 Jun 20187
S2R Stourpaine to Bryanston13 Jul 200431 May 20187
Canford Mill Stream31 May 201230 May 20182
S1R Fiddleford to Child Okeford20 Jul 200417 May 201810
S6 Child okeford8 Jun 201131 May 20174
S5R Iford Bridge to Hengistbury Head13 May 200421 May 20135
S4R Dudsbury to Merritown17 Jun 200416 May 20135
Muscliffe13 Sept 200710 Sept 20122
Kinson Manor Farm (Dudsbury)10 Sept 201210 Sept 20121
Throop5 Sept 20125 Sept 20121
S8 Blandford4 Sept 20124 Sept 20121
Canford School Reach31 May 201231 May 20121
S9 Spetisbury30 May 201230 May 20121
S10 White Mill30 May 201230 May 20121
The Ship Inn15 Jul 200424 Aug 20104
Throop u/s Glens Weir11 Sept 200911 Sept 20091
Throop d/s gauging Weir11 Sept 200911 Sept 20091
S3 Riversdale Farm15 Jul 200410 Jul 20095
S4 St Mary's Marnhull24 Jul 200211 Jun 20097
d/s Blandford Weir12 Sept 200712 Sept 20071
Hanford9 Jun 20059 Jun 20051
Canford School (top site S2S)11 Sept 200311 Sept 20031

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

2002–2025

Survey records by year

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

Fish measured by surveyors

Measured length distribution

See how the 3,669 measured fish were spread across different length ranges.

Smallest
1.8 cm
Lower quarter
11.4 cm
Median
14.4 cm
Upper quarter
18.4 cm
Largest
37.8 cm

Lengths are direct survey measurements rather than anglers’ catches.

Fish weighed by surveyors

Measured weight summary

Recorded weights were available for 115 roach. This is a subset of the measured fish and may not represent the whole population.

Lightest
0.4 oz (0.01 kg)
Lower quarter
2.1 oz (0.0605 kg)
Median
6.1 oz (0.173 kg)
Upper quarter
9.6 oz (0.2715 kg)
Heaviest
1 lb 12.2 oz (0.8 kg)

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

More fish in this river

Explore the Main river sites

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

Minnow Bullhead European eel Dace Stone loach Chub

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 →