Scotland’s salmon fishing industry is facing a serious threat from the effects of climate change, as rising sea temperatures cause mass mortalities and reduce the survival rates of young fish.
Since March 2023, Scotland’s waters have been gripped by an unprecedented Category 4 marine heatwave, causing mass marine mortalities. Salmon suffer stress in waters warmer than 23 degrees Celsius (73.4 degrees Fahrenheit), and as the climate warms, Scotland’s unshaded upland streams are hitting record temperatures. In 2018, the Gairn, a tributary of the Dee, reached 27.5 degrees, damaging young salmon stocks.
Salmon farms are also struggling with “biological” problems, such as sea lice or disease, which are exacerbated by higher water temperatures. Some of Scotland’s biggest salmon farms have reported significant and continuing challenges from these issues. There has also been a surge in jellyfish, which can clog the nets and suffocate the fish.
The decline in salmon populations has serious implications for the economy, the environment and the culture of Scotland. Salmon fishing is worth an estimated £200 million ($274 million) to the Scottish economy and supports more than 4,000 jobs5. Salmon are also a key species in the food chain, providing food for other animals such as otters, eagles and bears2. Moreover, salmon fishing is a cherished tradition for many Scots, who value the sport and the connection with nature.
To address this crisis, various measures are being taken by different stakeholders. The Scottish government has pledged to reduce greenhouse gas emissions by 75% by 2030 and to reach net zero by 2045. The River Dee Trust, a conservation charity, is planting trees along the river banks to provide shade and cool the water. The salmon farming industry is investing in new technologies and practices to improve fish health and welfare.
However, these efforts may not be enough to save Scotland’s salmon from the effects of climate change. As one angler lamented: “Anglers only want one. But it’s just not happening”.