Historic monitoring evidence · Environment Agency
Downstream of Shardeloes Lake
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.
Brown / sea trout
Salmo trutta- First record
- 13 May 2011
- Latest record
- 5 May 2026
- Survey events
- 3
Bullhead
Cottus gobio- First record
- 13 May 2011
- Latest record
- 5 May 2026
- Survey events
- 3
Rudd
Scardinius erythrophthalmus- First record
- 7 Jun 2019
- Latest record
- 5 May 2026
- Survey events
- 2
3-spined stickleback
Gasterosteus aculeatus- First record
- 13 May 2011
- Latest record
- 5 May 2026
- Survey events
- 2
Rainbow trout
Oncorhynchus mykiss- First record
- 5 May 2026
- Latest record
- 5 May 2026
- Survey events
- 1
Roach
Rutilus rutilus- First record
- 5 May 2026
- Latest record
- 5 May 2026
- Survey events
- 1
Rudd varieties
Scardinius erythrophthalmus- First record
- 13 May 2011
- Latest record
- 13 May 2011
- 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