Historic monitoring evidence · Environment Agency
Bretons
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.
Roach
Rutilus rutilus- First record
- 14 May 1996
- Latest record
- 26 Oct 2018
- Survey events
- 5
Common [wild] carp
Cyprinus carpio- First record
- 14 May 1996
- Latest record
- 26 Oct 2018
- Survey events
- 4
European eels > elvers
Anguilla anguilla- First record
- 15 Oct 2013
- Latest record
- 26 Oct 2018
- Survey events
- 2
Perch
Perca fluviatilis- First record
- 14 May 1996
- Latest record
- 15 Oct 2013
- Survey events
- 4
Gudgeon
Gobio gobio- First record
- 8 Jun 2000
- Latest record
- 15 Oct 2013
- Survey events
- 3
3-spined stickleback
Gasterosteus aculeatus- First record
- 1 Nov 2005
- Latest record
- 15 Oct 2013
- Survey events
- 2
Common bream
Abramis brama- First record
- 15 Oct 2013
- Latest record
- 15 Oct 2013
- Survey events
- 1
Mirror carp
Cyprinus carpio- First record
- 15 Oct 2013
- Latest record
- 15 Oct 2013
- Survey events
- 1
European eel
Anguilla anguilla- First record
- 14 May 1996
- Latest record
- 1 Nov 2005
- Survey events
- 3
Tench
Tinca tinca- First record
- 14 May 1996
- Latest record
- 8 Jun 2000
- Survey events
- 2
Goldfish varieties
Carassius auratus- First record
- 8 Jun 2000
- Latest record
- 8 Jun 2000
- Survey events
- 1
Chub
Leuciscus cephalus- First record
- 14 May 1996
- Latest record
- 14 May 1996
- Survey events
- 1
Dace
Leuciscus leuciscus- First record
- 14 May 1996
- Latest record
- 14 May 1996
- Survey events
- 1
Rudd
Scardinius erythrophthalmus- First record
- 14 May 1996
- Latest record
- 14 May 1996
- 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