Hot Weather Policy
Protecting fish welfare when temperatures climb.
Published by Peterborough & District Angling Association · Effective June 2026 · Version 1.0 · Approved by the P&DAA Leadership Team
1 Purpose and scope
This policy protects fish welfare at P&DAA waters during hot weather. It sets the water temperature and dissolved oxygen levels at which fishing is restricted or suspended, the handling that always applies in hot conditions, and who makes the decision.
It applies to all P&DAA waters, rivers and stillwaters, and to every member, day-ticket holder and match booking. It is based on Environment Agency Fisheries and Angling Trust hot-weather guidance, applied to our waters.
2 Why hot weather is a risk
Warm water holds less oxygen, and fish need more of it. The two move against each other as temperature rises. Larger, harder-fighting fish are most exposed, because they fight to exhaustion and go into oxygen debt. On our waters that means barbel first, then large chub and pike.
Low flows and falling levels make it worse. A smaller body of water warms faster and holds less oxygen. Oxygen is at its lowest at first light, after weed and plants have used it up overnight. The risk is highest when a heatwave arrives suddenly, before fish have had time to adjust.
3 Monitoring
- Carry a thermometer. Where a meter is available, measure dissolved oxygen (DO) as well.
- Take readings at first light, when oxygen is at its lowest. A midday reading reads higher and can mislead.
- During a hot spell the fishery team check temperature and DO daily, ideally at dawn, midday and late afternoon, and log the readings.
- Watch the water. Fish gathering at the surface or gasping is a direct sign of low oxygen. Act on it whatever the meter says.
4 Water temperature triggers
- Above 19°C: do not fish for salmon, trout or grayling.
- Above 21°C: do not fish for barbel, large chub or pike.
On faster, well-oxygenated water a degree or two higher may be tolerable. On slow, low-flow or canalised stretches, and in drought, lower the trigger. Where there is any doubt, err on the side of the fish.
5 Dissolved oxygen triggers
Healthy minimums are above 7 mg/l for coarse fish, and higher still for barbel, pike and large chub. Read the bands below as decision points for the water as a whole.
- At or below 7 mg/l: coarse fish are stressed and the hard fighters are at risk. Restrict.
- At or below 5 mg/l: fish recover poorly from capture. Suspend fishing.
- At or below 3 mg/l: fish-kill territory. No fishing. Deploy aeration if available and notify the Leadership Team.
6 Response ladder
The response steps up with the conditions. The affected water moves to the level set by whichever reading is worst, temperature or oxygen.
| Level | Conditions | What applies |
|---|---|---|
| Normal | Temperature below 19°C and DO above 7 mg/l. | Fish as usual. The hot-weather handling in section 7 still applies. |
| Restriction | Temperature 19–21°C, or DO 5–7 mg/l, or low flow. | Fishing permitted early morning only, when the water is coolest. Salmonids off above 19°C; barbel, large chub and pike off above 21°C. No keepnets. |
| Suspension | Temperature into the mid-20s°C, or DO at or below 5 mg/l, or fish in distress. | Fishing suspended on the affected water until conditions recover: a settled, cooler spell with DO back above 7 mg/l at dawn. |
7 Handling when fishing continues
Whenever fishing is allowed in warm conditions, the following apply on every P&DAA water:
- No keepnets. If one must be used, set it in the deepest water available, at right angles to the bank so any flow passes through it.
- Use tackle strong enough to land fish quickly. Do not play fish to exhaustion.
- Keep fish in the water while unhooking. Wet hands. Any photo is seconds out of the water, no more.
- Let fish recover in the net, supported, facing upstream on rivers, before release.
- Do not target or retain large, hard-fighting fish in marginal conditions.
8 Who decides, and how it is communicated
The Head of Fisheries decides a restriction or suspension on the basis of the readings. In their absence the decision falls to the Chairman.
The decision and the affected water are published on the club website, in the P&DAA app and on bankside notices. Matches booked during a restriction are rearranged, or run under the morning-only and no-keepnet conditions, at the organiser's discretion with fishery sign-off.
9 Reporting distressed or dead fish
Report any distressed or dead fish immediately to the Environment Agency incident hotline on 0800 80 70 60 (24 hours), and notify the fishery team. Early reporting gives the EA the chance to act before a localised problem becomes a kill.
10 Intervention
Where oxygen is falling, deploy aeration if it is available and move water where you can. Through a hot, dry spell:
- Avoid stocking until cooler conditions return.
- Avoid weed cutting that disturbs silt, and never pile cut weed on the bank, the run-off lowers oxygen further.
- Leave bankside shade and in-water cover in place. Both shade the water and shelter fish.
11 Review
This policy is reviewed each year before summer, and after any significant fish-welfare incident. The triggers are guidance points, not legal limits, and the fishery team may set them lower on any water where flow, depth or stocking density warrants it.
Version 1.0 · Effective June 2026 · Peterborough & District Angling Association.