Historic monitoring evidence · Environment Agency
Hertford Basin
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.
Perch
Perca fluviatilis- First record
- 15 Dec 1992
- Latest record
- 8 Jul 2025
- Survey events
- 15
Dace
Leuciscus leuciscus- First record
- 15 Dec 1992
- Latest record
- 8 Jul 2025
- Survey events
- 13
Roach
Rutilus rutilus- First record
- 15 Dec 1992
- Latest record
- 8 Jul 2025
- Survey events
- 13
Pike
Esox lucius- First record
- 30 Oct 2002
- Latest record
- 8 Jul 2025
- Survey events
- 9
Mirror carp
Cyprinus carpio- First record
- 22 Jul 2010
- Latest record
- 8 Jul 2025
- Survey events
- 3
Grass carp
Ctenopharyngodon idella- First record
- 8 Jul 2025
- Latest record
- 8 Jul 2025
- Survey events
- 1
Chub
Leuciscus cephalus- First record
- 24 Sept 2003
- Latest record
- 11 Jul 2024
- Survey events
- 5
Pike varieties
Esox lucius- First record
- 15 Dec 1992
- Latest record
- 11 Jul 2024
- Survey events
- 4
Ruffe
Gymnocephalus cernuus- First record
- 27 Sept 2006
- Latest record
- 11 Jul 2024
- Survey events
- 3
Barbel
Barbus barbus- First record
- 11 Jul 2024
- Latest record
- 11 Jul 2024
- Survey events
- 1
Common carp varieties
Cyprinus carpio- First record
- 11 Jul 2024
- Latest record
- 11 Jul 2024
- Survey events
- 1
Bleak
Alburnus alburnus- First record
- 24 Sept 2003
- Latest record
- 2 Aug 2023
- Survey events
- 8
Gudgeon
Gobio gobio- First record
- 27 Aug 2019
- Latest record
- 27 Aug 2019
- Survey events
- 1
Common bream
Abramis brama- First record
- 24 Sept 2003
- Latest record
- 24 Sept 2003
- Survey events
- 1
Zander
Sander lucioperca- First record
- 15 Dec 1992
- Latest record
- 15 Dec 1992
- 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