ARAnglerRadar evidence & rules

Historic monitoring evidence · Environment Agency

U/S Griggs Bridge

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.

8survey events
17 Oct 2017first recorded survey
2 Oct 2025latest recorded survey
8observed taxa shown

Separate-signal passport

What this record proves — and what it does not.

No blended quality score. Identity, monitoring, freshness, access and rules stay as separate signals so one strong fact cannot hide a missing one.

01 · Identity

Stable monitoring site

AnglerRadar ID
ea-fish-site:70543
EA waterbody ID
Not supplied
Waterbody
Quin
Catchment
Lee
02 · Observed evidence

Dated survey record

Scope
freshwater
Survey events
8
Positive taxa shown
8
Recorded methods
PDC ELECTRIC FISHING
03 · Freshness

Latest survey about 1 year ago

Coverage runs from 17 Oct 2017 to 2 Oct 2025. This is historic monitoring, never a live presence or catch forecast.

04 · Trip constraints

Access remains unresolved

The survey carries no fishing-rights boundary, permission, opening status or safety notice. Check the owner, rod licence, current byelaws and conditions separately.

Location protection: AnglerRadar does not print the survey coordinate on this page, and nearby API results use coarsened survey areas rather than exact species-linked points.

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
17 Oct 2017
Latest record
2 Oct 2025
Survey events
8

Bullhead

Cottus gobio
First record
17 Oct 2017
Latest record
2 Oct 2025
Survey events
8

3-spined stickleback

Gasterosteus aculeatus
First record
2 Oct 2018
Latest record
2 Oct 2025
Survey events
6

Minnow

Phoxinus phoxinus
First record
28 Oct 2021
Latest record
2 Oct 2025
Survey events
3

Brook lamprey > ammocoete

Lampetra planeri
First record
28 Oct 2021
Latest record
2 Oct 2025
Survey events
2

Lamprey sp. > ammocoete

Petromyzontidae
First record
2 Oct 2018
Latest record
31 Oct 2022
Survey events
2

Brook lamprey

Lampetra planeri
First record
17 Oct 2017
Latest record
28 Oct 2021
Survey events
2

Perch

Perca fluviatilis
First record
28 Oct 2021
Latest record
28 Oct 2021
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 rules

Provenance

Source, licence and boundary

Open the official dataset

More evidence nearby

Other surveyed waters in Hertfordshire and North London.

409 survey sites in this ecology region carry recorded taxa. Each keeps its own dates and source.

Browse Hertfordshire and North London survey sites →