Is this the case with Atlantics, our European species? Do their descendants subsist on their shredded flesh? No one knows.
The charm of the Atlantic’s salmon is that a small percentage do not die; having spawned, some survive. It is thought that around one in twenty live to spawn twice, and they are mostly females. This simple fact changes their whole definition from that of their Pacific cousins. Their softened bodies roll with the current towards the sea. Able to move pigment around their bodies, they have changed colour throughout their lives – in sandy-bottomed streams parr colour up sandy; put a cock salmon in a dark tank and cover the top and it darkens, faster towards spawning, but take him out and he pales. Now the sea-seeking fish silver up, fresh-minted; their bodies carry a latent promise of recovery, return and procreation again. Ancient Egypt’s Pharoahs would understand: they have an afterlife.
The passage to recovery is far from safe. Otters find them easy prey. Raucous gulls tug their barely sentient carcases from the shingle and devour them. Crows patrol the river edge for prey, squabbling over the rotten bodies. If any fortunate fish do manage to reach the ocean they run smack into hit-squads of patrolling sea mammals, in the form of grey and common seals. These far larger creatures can catch salmon by slashing them senseless with their flippers, and in a copy of sea-lion acts in the zoo, they flick them into the air, strip off the skins and swallow them as they fall.
The two seal species have protection in Europe, enjoying an almost complete prohibition on culling. Not consonant with the heavily managed catch quotas for all commercial fish, this status of sanctity and exclusion from management has its origin in the excesses of the whaling industry long ago. Whaling desecrated the populations of one of the world’s largest and most miraculous beasts in a hell-for-leather (sic) war on natural resources that has no historic parallels for goriness and intemperance. In the case of the American buffalo, one species was hunted down; in the case of the whales, several species were decimated. For whales are ocean mammals which have to surface and can therefore be seen. The oceans were raked and re-raked until almost none of the species with value were left. The scars from that era have entered Western psyches and will be a long time healing.
Seals are the major predators of fish close to the coast. Commercial fishermen have shown that they eat far more of the fish in the North Sea than fishermen are catching. However, for the time being the images of whiskered recumbent lumps straddling offshore rocks, doe-eyed saltwater Labradors, is forceful: they are sacrosanct. The only shots they have to put up with are from cameras. There is no public appetite for the resumption of anything that could look remotely like whaling, with any sea mammal. No one wants to risk a repeat of those haunting consequences.
As in some other stories we will come to, the reason for selective management is the secrecy of the sea. Beneath the waves, all is hidden. If the waters were peeled back from coastal north Scotland and the hundreds of thousands of large seals were made visible, attitudes might change. The fish would look miniature and vulnerable by comparison, their attackers gross and greedy. But we see what we see, and what we see, we believe.
Seals have trouble catching fast-moving salmon in open seas, but weakened by reproduction and their starvation in freshwater the post-coital ghosts drifting from river-mouths make easy pickings in late winter. Early spring salmon in colder waters move slower, and they are easier prey too.
A few salmon survive. No one knows what predestines these few fish to survive their ordeals, but they do. Maybe they are just the fortunate ones. Many species cling to existence with only small numbers of breeders. They say the fecund rabbit can breed a million descendants in its own lifetime. Adult ‘hen’ salmon produce some 800 eggs for each pound of their body weight, so a good fish of fifteen pounds would squirt from her quivering flanks into the redds some 12,000 eggs. If she beat the odds and returned to spawn twice, she might have grown and be able to produce more eggs the second time. The egg output, though, depends on seasonal and physical factors and can vary widely.
The most times any salmon returned that I have heard of was a fish that negotiated survival for eight re-runs, which was netted off Newfoundland and aged by scale-reading – a cross-cut scale being interpreted like the rings of a tree. This one must have been up near the rabbit in terms of prolific genetic legacy! Similar return rates have been recorded in some of the glorious rivers of New Brunswick. On the eastern side of the Atlantic, a fish analysed in Wales had returned to the redds five times.
It is in the northern oceans that depleted salmon rebuild their condition. If you were to catch and eat these salmon before they had reconstituted themselves, they would be oily and disagreeable, like cod or mackerel after spawning.
For a long time pundits tried to work out where salmon winter; it was akin to the mystical quest for the end of the rainbow. Somewhere a fish as long as your finger grew exponentially to become a fish as long as your arm. Where was this fabulous larder? It is known now that a proportion of British salmon winter off western Greenland, where Greenlanders in small boats net them close to the coast. These salmon stay more than one winter. They are a minority here; many larger salmon from North America fatten off Greenland too. A little further north, the salmon of the Russian Kola Peninsular and the salmon connected to rivers on Norway’s long coastline winter in the North Atlantic off Norway.
The salmon of eastern North America winter in the Labrador Sea and on the northern Grand Banks, as well as western Greenland. It can be overlooked: the distance across the Davis Strait starting from northern Newfoundland is only 600 miles. Greenland’s seas are a neighbourhood bouillabaisse. The fact of highly variable runs of east-coast salmon in North America is reckoned by scientists to be related to the environment, food supply and ocean temperature; so much is reasonably obvious. But unlike on the eastern side, where salmon-run prediction is not attempted, Canadian and American forecasts on fish runs are based on what is found in the sea off Newfoundland and Labrador when the water reaches four degrees. In the 1980s and 1990s, between Labrador and western Greenland sea temperatures were suppressed by Arctic waters pushing south. This in turn saw declining growth rates across species like capelin and cod, delayed spawning times and generally reduced salmon runs.
Not only are weather and climate unpredictable variables at sea, but living matter in the sea is infinitely complex. Any child at the seaside has noticed that if you bottle seawater the life seems to fade away. This is because the sea is a dynamic environment in a state of continuing flux. Filled with plankton, microscopic living particles of plants and animals, the sea is a bubbling broth. It has been calculated that the amount of organic material in an acre of sea equates to the vegetation on an acre of average land. Planktonic abundance fuels the vitality of seawater and is the foundation for a pyramid of creatures feeding from one predator level to the next.
Adult salmon are near the top of this pyramid. Fast swimmers, they evade other fish. Vulnerable to being cornered by seals and acrobatic sea mammals when in semi-confined areas like estuaries, they are generally too swift for capture. The rich soup of planktonic life becomes in turn the feed for krill, capelin, herring, shrimps and molluscs, which are all part of salmon’s ocean diet.
Important elements like phosphorus and nitrogen determine marine productivity. These either wash onto the shelves that are the underwater extensions of landmasses, or are pushed from below in the deep ocean by upwellings as ocean currents mix, driven by the Earth’s rotation. Areas of the ocean vary enormously in their productivity, the North Sea and the Grand Banks being shallow expanses and exceptionally fertile, as contrasted to vast parts of the mid-Pacific where the water, as you peer into it with the sun behind, is startlingly clear precisely because there is so little plankton and suspended material. It is as void as sterilised