Richard Hamblyn in the London Review of Books:
Salmon – the name, it’s thought, derives from the Latin salire, ‘to leap’ – has always been a fish apart, marked by its unusual capacity to migrate between the distinct worlds of salt and fresh water. According to William Camden’s Britannia (1586), the salmon leaps of Pembrokeshire were Britain’s first tourist attractions, at which scores of people would gather to ‘stand and wonder at the strength and sleight by which they see the Salmon get out of the Sea into the said River’. The spectacle remains one of the great sights of autumn, and people still crowd the banks of the Teifi to watch the returning salmon launch themselves at the cascading waters in brute determination to reach their ancestral spawning grounds upstream. Many don’t make it, but for those that do, it marks the end of an extraordinary circular migration that begins and ends in the same shallow gravel-beds to which every sea-run adult will seek to return at least once in its life: an impulse that was confirmed by Francis Bacon in the 1620s, when he tied ‘a Ribband or some known tape or thred’ around the tail of a sea-bound smolt, retrieving it the following year when the fish returned as a splendid silver grilse.
‘Smolt’, ‘grilse’: as Richard Shelton observes, salmon are spoken of in a ‘stained-glass language’ of their own, their life stages marked by an ichthyological lexicon unchanged since Chaucer’s time.
More here. [Thanks to J. E. H. Smith.]