Climate change casts a shadow over Britain’s biggest food export

Sir James Maitland, the eccentric owner of a Victorian hatchery in Stirlingshire, was probably the first Scot to breed the fish in captivity. (His recommended diet for salmon fry—horse meat and eggs—did not catch on.) But the industry took off only in recent decades. Technology from Norway, where the business was pioneered, combined with investment from Unilever, a consumer-goods conglomerate, to yield Scotland’s first salmon harvest in 1971. Production has exploded. In 2016 Scotland produced twice as much salmon as it did in 1996; the brand has cachet worldwide.