Hertfordshire and North London · Environment Agency surveys
What fish are in the Mimram?
Monitoring has recorded 24 species across 29 surveyed sites on this water, between 2003 and 2025. These are survey records with dates. They do not establish what is present today, that the water is fishable, or that you have permission to fish it.
Recorded species
What monitoring has found here
Ordered by how many sites on this water recorded the species. A species not listed has not been recorded by these surveys — which is not the same as being absent.
- Brown / sea troutSalmo trutta27 siteslatest 25 Sept 2025
- BullheadCottus gobio20 siteslatest 25 Sept 2025
- Stone loachBarbatula barbatula17 siteslatest 25 Sept 2025
- 3-spined sticklebackGasterosteus aculeatus16 siteslatest 25 Sept 2025
- 10-spined sticklebackPungitius pungitius9 siteslatest 7 Feb 2019
- GraylingThymallus thymallus9 siteslatest 25 Sept 2025
- MinnowPhoxinus phoxinus6 siteslatest 13 Jul 2006
- PikeEsox lucius5 siteslatest 2 Sept 2025
- Brook lamprey > ammocoeteLampetra planeri3 siteslatest 2 Sept 2025
- Brook lamprey ammocoetesLampetra planeri3 siteslatest 7 Sept 2023
- DaceLeuciscus leuciscus3 siteslatest 2 Sept 2025
- RoachRutilus rutilus2 siteslatest 7 Oct 2014
- RuddScardinius erythrophthalmus2 siteslatest 11 Oct 2018
- BleakAlburnus alburnus1 sitelatest 21 Sept 2010
- Brook lampreyLampetra planeri1 sitelatest 21 Sept 2011
- ChubLeuciscus cephalus1 sitelatest 13 Jun 2006
- Common carp varietiesCyprinus carpio1 sitelatest 4 Sept 2009
- European eelAnguilla anguilla1 sitelatest 13 Sept 2007
- Golden goldfishCarassius auratus1 sitelatest 10 May 2006
- GudgeonGobio gobio1 sitelatest 14 Oct 2003
- Lamprey sp.Petromyzontidae1 sitelatest 13 Jun 2006
- PerchPerca fluviatilis1 sitelatest 14 Oct 2003
- Pike varietiesEsox lucius1 sitelatest 20 Aug 2024
- Rudd varietiesScardinius erythrophthalmus1 sitelatest 21 Sept 2010
Surveyed sites on this water
29 shown, newest survey first
Tewin Flyfishers
- Survey events
- 18
- Observed taxa
- 8
- Latest survey
- 25 Sept 2025
Panshanger quarry
- Survey events
- 18
- Observed taxa
- 17
- Latest survey
- 2 Sept 2025
U/S Tewin Fly Fishers
- Survey events
- 2
- Observed taxa
- 3
- Latest survey
- 3 Oct 2024
Codicote restoration middle fully quant
- Survey events
- 3
- Observed taxa
- 5
- Latest survey
- 26 Sept 2024
Singlers Marsh
- Survey events
- 2
- Observed taxa
- 1
- Latest survey
- 26 Sept 2024
Duck Trap Wood
- Survey events
- 5
- Observed taxa
- 5
- Latest survey
- 30 Aug 2024
Rose Farm
- Survey events
- 3
- Observed taxa
- 4
- Latest survey
- 28 Aug 2024
Chandlers End, Mill Farm
- Survey events
- 5
- Observed taxa
- 6
- Latest survey
- 8 May 2024
Sherrardswood School
- Survey events
- 6
- Observed taxa
- 4
- Latest survey
- 5 Apr 2023
Codicote Station 1
- Survey events
- 7
- Observed taxa
- 3
- Latest survey
- 4 Apr 2023
Fulling Mill
- Survey events
- 7
- Observed taxa
- 5
- Latest survey
- 4 Apr 2023
Welwyn Allotments
- Survey events
- 2
- Observed taxa
- 2
- Latest survey
- 11 Aug 2021
Welwyn High Street
- Survey events
- 2
- Observed taxa
- 1
- Latest survey
- 10 Aug 2021
Tewin Archers
- Survey events
- 4
- Observed taxa
- 4
- Latest survey
- 23 Sept 2019
Tewin flyfishers middle
- Survey events
- 4
- Observed taxa
- 3
- Latest survey
- 23 Sept 2019
Codicote Station 2
- Survey events
- 4
- Observed taxa
- 5
- Latest survey
- 6 Feb 2019
Tewin Water House Investigation
- Survey events
- 1
- Observed taxa
- 1
- Latest survey
- 3 Oct 2018
Codicote restoration u/s
- Survey events
- 2
- Observed taxa
- 5
- Latest survey
- 6 Oct 2012
Panshanger quarry broadwater bypass channel
- Survey events
- 2
- Observed taxa
- 2
- Latest survey
- 21 Sept 2011
Codicote restoration d/s
- Survey events
- 1
- Observed taxa
- 3
- Latest survey
- 1 Mar 2007
Codicote restoration middle fixed effort
- Survey events
- 1
- Observed taxa
- 4
- Latest survey
- 28 Feb 2007
Rye end cottages
- Survey events
- 2
- Observed taxa
- 5
- Latest survey
- 26 Feb 2007
U/S Panshanger weir
- Survey events
- 1
- Observed taxa
- 6
- Latest survey
- 16 Jun 2006
Codicote bottom farm
- Survey events
- 1
- Observed taxa
- 5
- Latest survey
- 14 Jun 2006
School/corn mill
- Survey events
- 1
- Observed taxa
- 10
- Latest survey
- 13 Jun 2006
u/s Tewin Bury farm
- Survey events
- 1
- Observed taxa
- 5
- Latest survey
- 13 Jun 2006
Nanny Ford
- Survey events
- 1
- Observed taxa
- 1
- Latest survey
- 16 May 2006
Tewin Bury Farm
- Survey events
- 1
- Observed taxa
- 3
- Latest survey
- 19 Nov 2003
Cole Green Way Farm
- Survey events
- 1
- Observed taxa
- 7
- Latest survey
- 14 Oct 2003
Provenance
Source and licence
- SourceEnvironment Agency Ecology & Fish Data
- LicenceOpen Government Licence v3.0
- Source copy retrieved23 Jul 2026
- Waterbody nameAs published by the Environment Agency
- Not assertedCurrent presence, access, permission, fishing quality or safety