Fish-kills in England and game-angling banned in Wales and Ireland as June river temperatures top 20°C

Salmon fishing on the Galway Weir in County Galway was banned for twelve days due to excessively warm water temperatures.

As water temperatures spiralled upwards in the first half of June, there was a spike in fish-kills across UK rivers, with the north west of England being particularly badly affected, and game angling was banned in some rivers, due to the dangers of catch-and-release on the fish, along with widespread calls to ‘fish with caution’.

North-west fish-kills

The river Mersey and Manchester Ship Canal were the forefront with tens of thousands of dead fish found floating on the surface, the devastation reaching right into the heart of Manchester at Salford Quays. Fish-kills were also reported in: rivers Douglas, Alt, lower Irwell, Dane, Weaver, Mersey (Warrington) and the Warwickshire Avon, and also the Leeds & Liverpool Canal at Parbold, Bridgewater Canal (central Manchester) and Manchester Ship Canal at Partington.


In Ireland, Inland Fisheries Ireland (IFI) had to suspended angling at two of its most famous and prolific salmon fisheries. From Thursday, June 8, the Moy Fishery in Ballina, Co. Mayo and the Galway Fishery, in Galway City, had to close due to prolonged warm and dry weather conditions.

Due to salmon and trout suffering ‘thermal stress’ arising from the impact of adverse warm weather on them, the recent spell of dry and hot weather caused the water temperatures to exceed the 20⁰C threshold in both locations over a number of days.
Both the Moy and Galway fisheries are owned by the State, and operated by IFI. As a national conservation agency, IFI is mandated to protect the welfare of fish.

Barry Fox Head of Operations at Inland Fisheries Ireland (IFI) commented at the time: “Salmon need cold and clean water to survive and thrive. Low water volumes and high water temperatures can lead to fish kills, as there is less oxygen in the water to allow them to breathe”.

“It will take some time before water conditions at both locations will revert to normal for the month of June”, he said.

The situation changed with the onset of a low-pressure system from the Atlantic and thunderstorms moving in, and the ban was lifted on June 19 at both fisheries.

Fish with care

Elsewhere, some Wye and Usk lower beats closed as Welsh anglers were advised to fish with care by NRW. The river Wye was showing temperatures in excess of 20°C at EA-monitored points, and clubs on both the Wye and Usk were also considering closure temporarily. Fishing Passport beats on the Wye downstream of Hay-on-Wye were suspended for both salmon and trout and this was still in place at time of going to press.

NRW’s advice was for anglers to fish earlier in the day or late evening when the water cools off, with the fish being kept wet at all times, and should not be removed from the water to be weighed or photographed. NRW is also advising anglers to be patient when releasing the fish as they may need more time to revive to swim off strongly.

When temperatures top 20°C, NRW advise that it is too hot for salmon and sea trout, and that anglers should stop fishing. Mortality chances are high for salmon and sea trout at these temperatures, even with a proper catch-and-release technique.
Current Wales byelaws require any salmon or sea trout that is caught to be released safely into the water, using good catch-and-release principles.

Dr Ben Wilson, NRW Principal fisheries Advisor said: “Anglers need to consider whether they should be fishing at certain times during hotter weather.

“We know that water temperature has topped 20 degrees in parts of Wales recently; particularly in the rivers Wye and the Usk, so we advise against fishing for salmon or sea trout in these rivers until water temperatures have cooled.”
“We recommend that anglers keep in touch with their local association or club, or to use a water thermometer to make sure it is appropriate to fish.”

The Environment Agency claimed that any fish-kills were a natural event due to the loss of dissolved oxygen brought on by the hot weather. The Angling Trust argued, “These fish kills are yet more evidence of the appalling abuse our rivers face daily. What we have is another wake up call for the EA and DEFRA.
“As our climate changes, our rivers simply do not have the resilience to function in anything like a natural freshwater ecosystem. Through poor water quality, pollution and, in places, over abstractions and low flows, we have left our rivers unable to cope. The fish suffer because not one of our rivers is in a good chemical state and only 16 per cent are in a good biological state.”