Irish Rivers Close as Climate Crisis Threatens Native Fish
The climate emergency is forcing Irish authorities to take unprecedented action to protect our native fish species, with river closures becoming a stark reality as water temperatures soar beyond safe limits.
Inland Fisheries Ireland has implemented a groundbreaking warm water protocol over the past two years to safeguard cold water species including Atlantic salmon, sea trout and brown trout in the River Moy system flowing through County Mayo.
"Once water temperatures begin to encroach on 20 degrees, there is a need to try and minimise the amount of handling and additional stress that cold water species experience," explained Seán Kelly, a research officer with IFI who developed the scientific framework behind these protective measures.
A Climate Crisis Reality Check
The protocol's necessity became painfully evident during periods of extreme weather. While 2024's relatively mild, wet summer provided some respite, the previous year told a different story entirely.
The Erriff and Moy fisheries were forced to close on three separate occasions during periods of intense heat and drought, with closures in late May, late June and late July. Each closure lasted less than a week, but the message was clear: our changing climate is pushing Ireland's aquatic ecosystems to breaking point.
"We should think of them as polar species," Kelly noted, highlighting the precarious position of salmonoid fish in Ireland. "Here in Ireland, we are very close to the southern limit of the distribution of those species."
The Physiology of Crisis
When water temperatures exceed 18°C, fisheries enter a critical risk zone. At 20°C and above, the effects on cold water species can prove sub-lethal or even fatal. Unlike mammals, these fish cannot regulate their internal body temperature, making them entirely dependent on their aquatic environment.
During what scientists term "thermoregulation," stressed fish reduce their movements and eventually stop feeding altogether. This survival strategy makes any additional human interference potentially catastrophic.
"That is their coping strategy and that is why it is so critical that we minimise any additional stress that can exacerbate that compromised state they're in," Kelly emphasised.
A Conservation Emergency
The broader conservation picture paints an alarming trend. Salmon returns to Irish waters have plummeted from over 1.5 million in the 1970s to fewer than 200,000 in recent years, representing a catastrophic decline that mirrors the accelerating pace of climate breakdown.
As summers continue to warm under the relentless pressure of climate change, the narrow window of suitable habitat for these iconic Irish species continues to shrink. The protocol represents not just good environmental stewardship, but an urgent adaptation to our rapidly changing world.
Kelly remains cautiously optimistic about the protocol's effectiveness, noting that most anglers understand the long-term imperative. "Most anglers are ultimately conservationists. They're passionate about ensuring the long-term sustainability of the stocks continues into the future."
This initiative represents the kind of proactive, science-based environmental protection that Ireland needs as we confront the realities of climate change. It's a reminder that the climate crisis isn't some distant threat, it's reshaping our rivers, our wildlife, and our relationship with the natural world right now.