Название: The Salmon: The Extraordinary Story of the King of Fish
Автор: Michael Wigan
Издательство: HarperCollins
Жанр: Природа и животные
isbn: 9780007487653
isbn:
The interesting time for salmon-watching is late summer when numbers are building for the orgy of spawning. Upstream of the river-bridge to my home is the entrance to a tributary. Salmon gather below the bridge for the shade, perhaps, but also to wait for the right moment to run the tributary and spawn there. The place where they accumulate looks the same as the rest of the river-bed, a trifle deeper maybe, stones studding the sandy bottom. They have stations, places they like to be. These are not, as is often loosely said, ‘behind’ rocks, rather to the side or below. There they rest, pointing upstream, close to the bottom, occasional bubbles emerging lazily from their mouths, like giveaway wisps of smoke from rainforest tribes.
In the protection of this shady place at a certain point in the autumn the salmon numbers stack up in a diamond formation. To start with, a few just take positions here and there, but as spawning approaches they tighten into a formation. As the days pass and no rain raises water levels, the space they are occupying shrinks and gets cramped with more fish still arriving. It is like a rail terminus with no trains leaving. The water lacks the refreshment of oxygen. I have seen the mass of salmon get edgy and impatient; they start to jostle and swirl at each other. There is a palpable build-up of nervous tension.
One time this was dramatised in a remarkable way. Above the bridge swam a pair of mergansers, paddling on the side of the river. Like a torpedo in an old war movie, a large fish suddenly charged the two sawbills. He launched himself from at least 60 feet and, missile-like, broke the surface enough to create a bow-wave. The mergansers, sensing something at the last moment, rose in a panic of clattering wings and flew fast away.
Well, salmon do not in theory attack birds, but the fact is that mergansers are major predators of salmon eggs, a difficult enemy for the progenitors because the sawbills get their necks and beaks under the water and then shovel through the redds removing the buried caviar. Salmon hide the eggs in their redds and assume they are safe until the little alevins wiggle out in warming springtime sunshine; they cannot remain on duty to stand guard. I have seen a merganser in Canada surfacing from redd-raiding with salmon eggs cascading down its chest. I believe that cock salmon recognised in the merganser pair, with their elongated predator shape and thin heads, a predator enemy. It was a bird-fish interaction I will never see twice.
Prior to rain, the petulant salmon under the bridge are all moving and all disturbed. They squirt forward and drift back, they nudge other salmon, their tails swish and they shift position. Rain falls. I wait for the right conditions to see under the bridge again, despite it being harder with higher water. One time I had counted around 150 salmon in diamond-formation then, following rain, the river-bed where they had been was denuded of every one. The breeding pack had moved on to the final stage: the upper tributaries and the redds.
I was taught by an old fishing ghillie how to read water at this point in the salmon chapter and to detect the presence of a river’s spawners from water movement. It is an art. You walk upstream from below, although from above is possible too. The spawners are in certain types of places, at least where I view them they are. They occupy the fast water beside and behind the bigger stones – they like active water with energy. To start with they are not in the fastest riffly current, which is shallow, but in the channels by big rocks. From below you see not the fish but the bulge in the water above where they lie. Their bodies are never long still, so the water has a thicker, darker look. Momentarily they move and a fin-edge shows. Then the fin of the partner fish, close by. If you walk up the bank opposite to the fish you can watch the pair of them. Only if you wade into the water do they swim off. It is not like in the fishing season; these creatures have a special matter on their minds, nothing less than their definitive act. As spawning time approaches they move into the faster riffles.
In Canadian fishing huts and fishing lodges and airports near fishing rivers, one man’s quotations often adorn the public spaces. They are the words of Roderick Haig-Brown, a judge in his day and resident on the banks of the Campbell River on Vancouver Island. In his book Return To The River he describes the drama on a spawning redd of a female Chinook salmon, a stupendously big fish for the little rivers it breeds in.
No one who has read Haig-Brown’s account will feel brave enough to attempt their own description. His spare, detailed and probing simple language turns the enactment of egg-release into a pageant of wildlife drama. He describes the hen’s convulsing flanks as she releases eggs, redd-digging with fierce sweeps of her mighty tail, the water current helping the process. Then the arrival of the cock squirting his cloudy milt over the egg pile, the competing immature Chinook rushing in to have his go at contributing to procreation, prior to the whole nest being rapidly covered with pebbles in protection from the throng of potential predators needing just such a feast of fresh protein before the onset of north Canadian winter rigour.
At last he describes her dying, being eaten alive by rot, the fungus which softens and breaks down the flesh. Our heroine mother is left disintegrating on the stones. But, critically in Nature’s cycle, her dismembering body flakes feed vital protein to young fish and her distant successors. It is noble writing, and gripping. In stately style he takes longer over some passages of this enactment than the real-life duration.
To watch salmon spawning is an elevating experience available to anyone living in salmon country anywhere. Yet we are glued to wildlife films for their perfecting, high-tech, laboratory touching-up, editing and enhancing. Nothing can give you the smell of the real-life river at spawning, the proximity, and the clarity.
Usually between sundown and midnight, working upstream, the hen turns on her side and scoops a depression in a sandy and gravelly substratum, laying eggs all the while in a steady outpouring. The eggs remain fertile for only one minute, so contenders vie to fertilise them, squirting their cloudy milt. Action is furious. The redds are then covered over with the same stone-shovelling to a depth of up to a foot.
I saw this process one time on a gravel-bar below my house late in November after most fish had spawned. The salmon were same-sized, around 35 pounds. I had recently handled some big salmon and although fish of this size are seldom seen in the River Helmsdale, that was the class of fish I was watching. She lay just in front of him, but instead of a vigorous and exhausting performance these two were in languorous mode. They were so large that no grilse, parr or other contenders were visibly around. Their backs were clear of the water, and the two giants seemed just to nudge each other on the redd. I had two of my children with me and, riding piggy-back, they could see it all from a better height only a few yards across the stream. I almost felt like going away out of politeness.
Enquiring later about the presence of such leviathans, a retired fishery bailiff told me he had long known about these very big salmon. They entered this river after angling had finished, often not till November, and stayed only long enough to spawn. He reckoned they were usually no more than a fortnight in fresh water.
The salmon eggs are clustered in the redds until they hatch, safe from most eventualities except major flooding when rolling rock could smash their soft mounds and disperse the egg collection for consumption by all and sundry. For there are few denizens of salmon headwaters for whom fresh eggs are not a welcome dietary enhancement. Unlucky clutches too near the surface can be frozen solid on gravel-bars exposed to hard frost which has driven down water levels. Redds are safe if there is stability in the river system until they hatch in the spring.
The actors in the conception drama have changed their costumes to participate. Both sexes’ noses become extended. If he were a medieval knight trying to unnerve his jousting opponent, the features the cock salmon arraigns himself in might fit the bill. He grows a lower-jaw projection in the form of a solid gristle hook which curves up, sometimes actually piercing the cartilage of his upper mouth, which itself arches, pre-spawning, to accommodate it. The knob has a name, the ‘kype’, but its purpose is uncertain. Salmon fishery managers have СКАЧАТЬ