Historic monitoring evidence · Environment Agency
Hartham Common
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
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 15
Dace
Leuciscus leuciscus- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 15
Roach
Rutilus rutilus- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 14
Perch
Perca fluviatilis- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 14
Gudgeon
Gobio gobio- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 13
Barbel
Barbus barbus- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 12
Minnow
Phoxinus phoxinus- First record
- 22 Aug 2003
- Latest record
- 21 Jun 2018
- Survey events
- 12
Pike
Esox lucius- First record
- 24 Oct 2002
- Latest record
- 21 Jun 2018
- Survey events
- 10
Common [wild] carp
Cyprinus carpio- First record
- 2 Jul 2013
- Latest record
- 21 Jun 2018
- Survey events
- 4
Bullhead
Cottus gobio- First record
- 24 Oct 2002
- Latest record
- 12 Jul 2016
- Survey events
- 9
Common bream
Abramis brama- First record
- 21 Sept 2004
- Latest record
- 12 Jul 2016
- Survey events
- 8
Ruffe
Gymnocephalus cernuus- First record
- 22 Aug 2003
- Latest record
- 12 Jul 2016
- Survey events
- 7
Bleak
Alburnus alburnus- First record
- 22 Aug 2003
- Latest record
- 25 Jun 2015
- Survey events
- 11
Pike varieties
Esox lucius- First record
- 25 Aug 2005
- Latest record
- 23 Jun 2011
- Survey events
- 5
Roach x dace hybrid
Rutilus rutilus x Leuciscus leuciscus- First record
- 26 Sept 2006
- Latest record
- 26 Sept 2006
- Survey events
- 1
Roach x common bream hybrid
Rutilus rutilus x Abramis brama- First record
- 26 Sept 2006
- Latest record
- 26 Sept 2006
- Survey events
- 1
Brook lamprey > ammocoete
Lampetra planeri- First record
- 21 Sept 2004
- Latest record
- 21 Sept 2004
- Survey events
- 1
Brown / sea trout
Salmo trutta- First record
- 22 Aug 2003
- Latest record
- 22 Aug 2003
- Survey events
- 1
Tench
Tinca tinca- First record
- 22 Aug 2003
- Latest record
- 22 Aug 2003
- Survey events
- 1
3-spined stickleback
Gasterosteus aculeatus- First record
- 22 Aug 2003
- Latest record
- 22 Aug 2003
- 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