Direct individual measurements
Largest allis shad by waterway
Ranked by the largest individual measured in EA surveys. The sample size shows how many valid length measurements underpin each waterway's figures.
| Rank | River or waterway | Largest | Median | Measured | Measured at |
|---|---|---|---|---|---|
| 1 | River Main TamarSouth West | 57 cm (22.4 in) | 49.7 cm (19.6 in) | 21 | 22 Jun 2011Gunnislake Weir Index River Fish Trap |
| 2 | River OuseYorkshire and North East | 43.4 cm (17.1 in) | 43.4 cm (17.1 in) | 1 | 21 Jul 2000Naburn Weir (boom boat site) |
Equal maximum lengths are ordered by sample size. Measurements are shown as recorded and are not converted into estimated weights.
22 fish measured
Measured allis shad lengths
The median divides the measured sample in half. This distribution describes surveyed fish, not every allis shad living in England.
Only positive individual lengths that pass RiverFish's general measurement checks are included. Each bar covers a 20 mm range.
Latest EA evidence
Latest allis shad observations
The ten most recent survey visits that recorded allis shad in named waterways.
| Date | River or waterway | Survey location | Fish recorded |
|---|---|---|---|
| 26 Jun 2018 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 1 |
| 29 May 2018 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 2 |
| 3 Jun 2013 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 1 |
| 9 May 2012 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 1 |
| 4 Jul 2011 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 1 |
| 22 Jun 2011 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 4 |
| 21 Jun 2011 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 1 |
| 15 Jun 2011 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 2 |
| 14 Jun 2011 | River Main Tamar | Gunnislake Weir Index River Fish Trap | 8 |
| 21 Jul 2000 | River Ouse | Naburn Weir (boom boat site) | 1 |
A survey record confirms allis shad at that place and time. It does not show present-day abundance or fishing access.
10 positive survey visits
Survey distribution
EA surveys recorded allis shad at 2 locations across 2 named waterways represented on RiverFish.
| Region | Waterways | Locations | Survey visits | Latest record |
|---|---|---|---|---|
| South West | 1 | 1 | 9 | 26 Jun 2018 |
| Yorkshire and North East | 1 | 1 | 1 | 21 Jul 2000 |
1 detailed pages
Allis shad by river
Open any river-specific page for its measured lengths, largest surveyed individuals, locations and observation history.
South West 1 pages
How to read this page
Survey measurements, not angling records
Environment Agency surveys are designed to monitor fish populations. Their largest measurement is not equivalent to a verified rod-and-line record, and the survey sample does not include every river or every allis shad.
Waterway groups with administrative or mixed-river labels are excluded from the headline national totals and rankings. Their eligible river-specific pages remain available in the directory so no published destination is hidden.
The fish records use the Environment Agency source snapshot dated 10 August 2026.
How RiverFish handles the data →