Debate: woodcock vs. salmon (Part 2)
Both undertake epic migrations, but which is the true champion?
IN THE SALMON CORNER: Michael Wigan, author of 'The Salmon - the extraordinary story of the king of fish'.
Extraordinary migrations are being discovered all the time: Arctic terns winging it from pole to pole, phalaropes and other small waders with their febrile movements doing the Arctic to UK crossing, not to mention the better-known Atlantic salmon, our own one, edging out to Greenland's coast to get fighting-fat for reproduction.
More astounding, perhaps, is the fact that the journey starts with a pencil-long silver sliver breasting into an ocean filled with potent enemies. Maybe only the slender common eel elver, starting from the Sargasso Sea, is vulnerable to this degree.?
Unlike some migrating birds, the miniature salmon has no guides, no seniors pointing the way, no outriders scouting danger; it is just itself, a little fish urgently needing to accumulate weight and gain getaway speed. It chases oil-rich sandeels on the sandbanks; any piscine turbo-fuel will do. As to smolts as food themselves, barring bottom-feeders, almost everything they could encounter is an enemy.
Beware, smolts, of swimming with herring. You might get swept up in the pelagic nets of Norway's herring and mackerel fishing fleet, operating in the sovereign Norwegian Sea, outside international agreements. ICES reports that ?high numbers' of young salmon are taken as a by-catch in these surface trawls. It is known too, through tagging, that they come from southern Europe.
Many UK smolts travel north on the Norwegian Shelf as established by SALSEA, the one-off international programme which tracked smolts by actually netting them in open water - an amazing feat. The smolts adhered to a narrow band of the rich upwelling current right on the shelf. This was an important finding.
Let's assume the quick-growing smolt holes up off western Greenland if it is to be a multi-sea winter mature salmon, and somewhere north of Iceland if destined to be a grilse. This is the zone for consumption of capelin, small floating shrimps and crustaceans, and the larvae of fish like blue whiting, vitamin-extra diet-packs for young salmon.
The fish in these northerly zones are fewer by species but greater by number. Cod, herring and mackerel are all here. Their diets are not known in enough detail to estimate the young salmon component. Salmon themselves eat almost anything they can grapple with. This includes the mysterious deeps-dwelling lantern-fish, caught mid-water as they rise towards the surface in the night, and also barracudinas. Salmon are un-fussy omnivores.
A more measurable threat than predatory fish is Greenland's drift-net salmon fishing. To date, Orri Vigfusson's Reykjavik-based NASF has handled negotiations with Greenland, paying handsomely for partial suspension of the August to October netting with an agreed subsistence quota.?
But for the last two years no money has changed hands, and Greenland has netted more than the previously agreed quota of 20 tons, equivalent to some 7,400 salmon. Greenlanders highlight the fact that Scotland nets more than they do (28,000 salmon in 2013), and Scottish fishermen have a wealth of alternative fish to catch.
In an end of July statement, the Greenland government restricted the 2014 net fishery to 30 tons, or some 11,100 salmon. So our wintering salmon, mixing in this feeding-ground with eastern Canadian and American salmon, may evade capture in this faraway zone. But for any river with just a few large breeders - some eastern American rivers have stocks suspended on lifelines of just a few dozen pairs - any losses at all represent dicing with genetic survival.
To replicate itself, the salmon must return home. No-one knows what triggers salmon migration, or fitness to move. Scientists say loosely, body condition. But what makes an already big salmon stay three years on the wintering grounds instead of two? Or stay for four? Or why do small two sea-winter salmon up sticks and head for home?
All we know is that in Scotland the trend is to stay away longer. From scale-reading it is known that a quarter of the run is of older three sea-winter salmon. Some postulate that the feeding-grounds shifting further north owing to higher temperatures means salmon need longer to prepare for a tougher journey.
Replete with Arctic bounties, the silver fish then faces south and east. Its route is unknown. It may dive down to 600m. Normally, it is nearer the surface. The returning salmon seeking its natal river is not in eating mode. After June, British salmon do not feed much at sea. If they reach coastal home waters they shoal and wait. Their set purpose is to find a partner and breed, in a dramatically shrunk environment compared to the boundless ocean they are about to leave.
How do they locate home? There is a mineral called magnetite in their heads. It responds to electro-magnetic fields. This is assumed to play a part in re-location to the nursery they came from so many years ago. There is also the water chemistry in the old nursery stream. Every river has differing geology and differing chemistry. The questing salmon sifts these smells and taints, as it shifts closer to the estuary mouth, wary of ravening seals.
Assuming a decent tide and fresh rain in the headwater hills, our great traveller is back in his or her home river. His system has adjusted, momentously, from saltwater to fresh. Familiarity at last. A reassuringly familiar river landscape and water-smell.?
And there on the bank, optimistically wielding his trusty fishing-pole, is the great protector, the salmon angler. It is this individual who has done most to look after salmon and ensure their survival. It is this individual who has put his money where his mouth is to look after the river habitat and huge marine universe of the salmon. This is the salmon's true champion.
In recognition of these tireless efforts the big fish lazily swirls at the fly, rekindling in the besotted angler yet another round of pro-salmonid lobbying and financing, and of biological speculation. Unlike his Pacific cousins, this fish could repeat the odyssey described, even more than twice. A salmon was once netted off Wales which had bred eight times; from the Barents Sea and into the Kola and northern Norwegian rivers - multiple returners are common. Where salmon are concerned, miracles never cease?
Painting: Chris Sharp