Historic monitoring evidence · Environment Agency
Picketts Lock
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
- 16 Mar 1993
- Latest record
- 10 Jul 2025
- Survey events
- 18
Perch
Perca fluviatilis- First record
- 16 Mar 1993
- Latest record
- 10 Jul 2025
- Survey events
- 18
Common bream
Abramis brama- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 13
Bleak
Alburnus alburnus- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 11
Pike
Esox lucius- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 9
European eels > elvers
Anguilla anguilla- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 8
Tench
Tinca tinca- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 6
Dace
Leuciscus leuciscus- First record
- 3 Oct 2003
- Latest record
- 10 Jul 2025
- Survey events
- 5
Chub
Leuciscus cephalus- First record
- 10 Jul 2013
- Latest record
- 10 Jul 2025
- Survey events
- 3
Silver bream
Abramis bjoerkna- First record
- 8 Sept 2006
- Latest record
- 9 Jul 2024
- Survey events
- 8
Rudd
Scardinius erythrophthalmus- First record
- 8 Sept 2006
- Latest record
- 9 Jul 2024
- Survey events
- 2
Gudgeon
Gobio gobio- First record
- 3 Sept 2004
- Latest record
- 12 Aug 2019
- Survey events
- 10
Zander
Sander lucioperca- First record
- 3 Oct 2003
- Latest record
- 12 Aug 2019
- Survey events
- 2
Ruffe
Gymnocephalus cernuus- First record
- 3 Oct 2003
- Latest record
- 27 Jul 2016
- Survey events
- 3
European eel
Anguilla anguilla- First record
- 16 Mar 1993
- Latest record
- 10 Jul 2013
- Survey events
- 6
Common [wild] carp
Cyprinus carpio- First record
- 18 Jul 2012
- Latest record
- 18 Jul 2012
- Survey events
- 1
Pike varieties
Esox lucius- First record
- 16 Mar 1993
- Latest record
- 26 Jul 2011
- Survey events
- 5
Common carp varieties
Cyprinus carpio- First record
- 8 Sept 2008
- Latest record
- 26 Jul 2010
- Survey events
- 2
Tench varieties
Tinca tinca- First record
- 23 Jul 2009
- Latest record
- 23 Jul 2009
- Survey events
- 1
Roach x common bream hybrid
Rutilus rutilus x Abramis brama- First record
- 3 Oct 2003
- Latest record
- 8 Sept 2005
- Survey events
- 3
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