Climate Crisis Forces River Closures to Save Irish Fish
The climate emergency is forcing unprecedented action to protect Ireland's precious salmon and trout populations, with fisheries now closing when river temperatures become lethal for cold-water species.
Inland Fisheries Ireland has implemented a groundbreaking warm water protocol on the River Moy in Mayo, marking a sobering milestone in our fight against climate breakdown. The protocol, developed over two years of scientific research, represents both an innovative conservation response and a stark warning about our environmental future.
"Once temperatures exceed 20 degrees, which is known to increase sub-lethal or even lethal effects related to angling on these species, the fishery can close," explained Seán Kelly, a research officer with IFI who helped develop the scientific framework.
The Errif and Moy fisheries closed three times last year during extreme heat periods in late May, June, and July. Each closure lasted less than a week, but the implications stretch far beyond temporary inconvenience.
A Species Under Siege
Ireland's Atlantic salmon, sea trout, and brown trout are essentially polar species clinging to survival at the southern edge of their natural range. As Kelly puts it: "We should think of them as polar species. Here in Ireland, we are very close to the southern limit of the distribution of those species."
The numbers tell a devastating story of ecological collapse. During the 1970s, over 1.5 million salmon returned to Irish waters. Today, that figure has plummeted to fewer than 200,000, a decline that mirrors broader environmental degradation across our island.
When water temperatures rise above 18°C, these cold-adapted fish enter a danger zone. Above 20°C, they face potentially lethal stress. Unlike mammals, fish cannot regulate their body temperature, forcing them into a survival state called thermoregulation where they stop feeding and reduce movement.
Conservation Through Crisis Management
The protocol requires continuous temperature monitoring throughout the day. If readings exceed 20°C twice within 24 hours, the fishery closes immediately. While 2024's cooler, wetter summer provided temporary relief, last year's heat waves demonstrated the urgent need for such measures.
"Having the fisheries closed during periods when river temperatures were in excess of 20°C, we can say with a high degree of certainty we would've minimised any additional unnecessary injuries or mortality," Kelly confirmed.
The response from the angling community has been largely supportive, reflecting a broader understanding that short-term restrictions serve long-term conservation goals. As Kelly notes: "Most anglers are ultimately conservationists. They're passionate about ensuring the long-term sustainability of the stocks continues into the future."
A Window Into Ireland's Climate Future
This protocol represents more than fisheries management; it's a preview of the adaptive measures Ireland will need as climate impacts intensify. The narrow window of suitable habitat for these species continues shrinking with each warming summer.
For a nation that prides itself on pristine waters and world-class angling, these closures serve as a powerful reminder that climate action cannot wait. The fish struggling in our warming rivers today are canaries in the coal mine of Ireland's environmental future.
As we face the reality of a changing climate, innovative conservation measures like the warm water protocol offer hope that science-based intervention can still protect what remains of our natural heritage. But they also underscore the urgent need for comprehensive climate action to address the root causes of environmental breakdown.