Historic monitoring evidence · Environment Agency
Watford M1 link road
Hertfordshire and North London · survey site
This page records ecological survey evidence. It is not proof of current fish presence, abundance, fishing quality, access, permission or safety at this location.
Observed taxa
What monitoring recorded here
Taxa are ordered by latest survey date. Counts and records reflect monitoring events, not an angling forecast.
Chub
Leuciscus cephalus- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 19
Dace
Leuciscus leuciscus- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 19
Roach
Rutilus rutilus- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 19
Gudgeon
Gobio gobio- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 18
Bullhead
Cottus gobio- First record
- 10 Jul 2003
- Latest record
- 22 Jul 2025
- Survey events
- 16
Minnow
Phoxinus phoxinus- First record
- 10 Jul 2003
- Latest record
- 22 Jul 2025
- Survey events
- 16
Perch
Perca fluviatilis- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 15
Pike
Esox lucius- First record
- 21 Sept 2000
- Latest record
- 22 Jul 2025
- Survey events
- 14
Stone loach
Barbatula barbatula- First record
- 10 Jul 2003
- Latest record
- 22 Jul 2025
- Survey events
- 11
3-spined stickleback
Gasterosteus aculeatus- First record
- 21 Jul 2004
- Latest record
- 27 Jun 2024
- Survey events
- 4
Silver bream
Abramis bjoerkna- First record
- 27 Jun 2024
- Latest record
- 27 Jun 2024
- Survey events
- 1
Barbel
Barbus barbus- First record
- 12 Jul 2018
- Latest record
- 22 Jul 2019
- Survey events
- 2
Pike varieties
Esox lucius- First record
- 22 Jul 2005
- Latest record
- 5 Jul 2012
- Survey events
- 4
Grayling
Thymallus thymallus- First record
- 28 May 2009
- Latest record
- 28 May 2009
- Survey events
- 1
Brown / sea trout
Salmo trutta- First record
- 25 Jul 2008
- Latest record
- 25 Jul 2008
- Survey events
- 1
Rules and access
Check before you travel.
Environment Agency ecology records do not carry fishing-rights boundaries or live restrictions. Confirm the fishery owner, permission, local byelaws, seasonal rules, safety notices and current conditions before setting out.
Check live freshwater fishing rulesProvenance
Source, licence and boundary
- SourceEnvironment Agency Ecology & Fish Data
- LicenceOpen Government Licence v3.0
- Source copy retrieved23 Jul 2026
- Terms checked23 Jul 2026
- CoverageHistoric monitoring evidence, separately dated per record
- Not assertedCurrent presence, access, permission, fishing quality or safety