Record numbers of salmon have been recorded in the River Tyne, making it the best river for the species in England and Wales.
A fish counter at a Northumbrian Water pumping station at Wylam recorded 9,240 salmon and sea trout during July.
There had been concern that low levels of oxygen in the water caused by the spell of hot and dry weather during the month would damage their welfare.
Already this year almost 15,000 have migrated up the river to spawn.
The fish counter works by using electrodes attached to a weir at the pumping station.
When a fish passes over them, a signal is generated which is sent to the counter for analysis.
This can distinguish between upstream and downstream movements of fish, and also eliminates results caused by debris in the river.
Scientists from the Environment Agency use the data to monitor fish populations in the river, and make decisions about how best to manage them in the future.
Phil Rippon, Fisheries Technical Specialist for the Environment Agency, said: "This year's fish counts are very encouraging, especially in view of relatively poor runs of sea trout in recent years.
"We monitor rod catches of salmon and sea trout from rivers nationally, and the data shows the Tyne to be the best river in England and Wales."