ARAnglerRadar evidence & rules

Hertfordshire and North London · Environment Agency surveys

What fish are in the Ash (Hertfordshire and North London)?

Monitoring has recorded 20 species across 13 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.

  1. Brown / sea troutSalmo trutta13 siteslatest 18 Sept 2025
  2. BullheadCottus gobio12 siteslatest 18 Sept 2025
  3. MinnowPhoxinus phoxinus11 siteslatest 18 Sept 2025
  4. 3-spined sticklebackGasterosteus aculeatus9 siteslatest 18 Sept 2025
  5. Brook lampreyLampetra planeri6 siteslatest 18 Sept 2025
  6. Stone loachBarbatula barbatula6 siteslatest 18 Sept 2025
  7. Lamprey sp.Petromyzontidae5 siteslatest 15 Sept 2010
  8. RoachRutilus rutilus5 siteslatest 19 Sept 2023
  9. Brook lamprey > ammocoeteLampetra planeri4 siteslatest 29 Oct 2021
  10. GraylingThymallus thymallus4 siteslatest 18 Sept 2025
  11. PerchPerca fluviatilis4 siteslatest 19 Sept 2023
  12. ChubLeuciscus cephalus3 siteslatest 28 Sept 2023
  13. PikeEsox lucius3 siteslatest 12 Sept 2019
  14. Pike varietiesEsox lucius3 siteslatest 15 Sept 2011
  15. Brook lamprey ammocoetesLampetra planeri2 siteslatest 22 Oct 2021
  16. DaceLeuciscus leuciscus2 siteslatest 28 Sept 2023
  17. GudgeonGobio gobio2 siteslatest 19 Sept 2023
  18. 10-spined sticklebackPungitius pungitius1 sitelatest 16 Oct 2007
  19. Rainbow troutOncorhynchus mykiss1 sitelatest 22 Jun 2006
  20. TenchTinca tinca1 sitelatest 29 Oct 2021

Surveyed sites on this water

13 shown, newest survey first

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