格陵兰鲨鱼 (2020)
Consider the Greenland Shark (2020)

原始链接: https://www.lrb.co.uk/the-paper/v42/n09/katherine-rundell/consider-the-greenland-shark

## 格陵兰鲨:一位古老的航海者 在1606年伦敦瘟疫等历史动荡中,一种寿命极长的生物默默地穿梭于世界海洋:格陵兰鲨。最近发现,它是已知寿命最长的脊椎动物,一些个体估计超过500岁——见证了数个世纪的人类历史,甚至早于尤利乌斯·凯撒。 科学家通过分析其眼球晶状体中的碳-14水平来确定它们的年龄。这些鲨鱼独特地适应了寒冷的海底,拥有缓慢的新陈代谢,所需的营养极少,并且体内富含尿素,具有防冻性能,但同时也产生了一种刺鼻的氨气味。 尽管体型巨大——可达24英尺——它们却是行动迟缓的猎手和食腐动物,以海豹到驯鹿等各种生物为食。它们的韧性令人瞩目;即使在“死亡”后,它们的肌肉还会持续收缩数天。然而,它们缓慢的繁殖速度以及过去因其有价值的肝油而遭受的过度捕捞构成了潜在的威胁。 由于它们主要栖息在深海,研究它们仍然充满挑战,它们的生活习性在很大程度上仍然是个谜。然而,它们持久的存在提供了一种谦卑的视角,表明它们将超越人类当前的挑战,并见证地球未来的变革。

## 黑客新闻讨论:格陵兰鲨鱼与深海生物 最近黑客新闻上围绕凯瑟琳·伦德尔的文章《考虑格陵兰鲨鱼》展开了讨论。这篇文章引发了关于深海生物极慢的新陈代谢以及对海底疏浚和采矿等活动的影响的对话,这些活动可能破坏需要数千年才能恢复的生态系统。 用户们注意到格陵兰鲨鱼惊人的寿命——可能从1850年代就开始游动——并提到了它在赫尔曼·梅尔维尔的《白鲸》中的出现,强调了历史上将鲸鱼归类为“鱼”的观点(源于允许在周五食用的宗教习俗)。 讨论扩展到更广泛的话题,例如古老森林的寿命以及经典文学作品中经常被忽视的细微差别。一个分支探讨了格陵兰鲨鱼可能栖息在尼斯湖等淡水环境中的可能性,但这一观点在很大程度上被驳斥了。最后,许多人将文章标题与大卫·福斯特·华莱士的文章《考虑龙虾》以及随后在硅谷流行的“考虑X”模因联系起来。
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原文

In​ 1606 a devastating pestilence swept through London; the dying were boarded up in their homes with their families, and a decree went out that the theatres, the bear-baiting yards and the brothels be closed. It was then that Shakespeare wrote one of his very few references to the plague, catching at our precarity: ‘The dead man’s knell/Is there scarce asked for who, and good men’s lives/Expire before the flowers in their caps/Dying or ere they sicken.’ As he wrote, a Greenland shark who is still alive today swam untroubled through the waters of the northern seas. Its parents would have been old enough to have lived alongside Dante; its great-great-grandparents alongside Julius Caesar. For thousands of years Greenland sharks have swum in silence, as above them the world has burned, rebuilt, burned again.

The Greenland shark

The Greenland shark (photo © Nick Caloyianis/National Geographic Creative)

The Greenland shark is the planet’s longest-lived vertebrate, but it was only recently that scientists were able to ascertain exactly how old they might be. In 2008, Jan Heinemeier, a Danish physicist, discovered a way to test lens crystallines, a protein found in the eye, for carbon-14. The amount of carbon-14, a radioactive isotope, found naturally on Earth varies from year to year; there were huge spikes during the 1960s, when mankind was at its most enthusiastic about nuclear weapons, but every period has its own carbon-14 signature. By testing the crystallines in the sharks’ eyes, it was possible to determine, very roughly, their date of birth: of 28 tested, the largest, a 16-foot female, was reckoned to be somewhere between 272 and 512 years old. Size is a relatively good indicator of age, and there are records of sharks reaching 24 feet long; so it’s very possible that there are sharks in the water today who are well into their sixth century.

The Greenland shark is not obviously beautiful. Its face is blunt, its fins stunted, and its eyes attract a long worm-like crustacean, ommatokoita elongata. These attach themselves to the cornea of the sharks’ eyes, fluttering from their eyeballs like paper streamers, rendering them both almost blind and more disgusting than seems fair. They smell, too. Their bodies have high concentrations of urea; a necessity, to ensure they maintain the same salt concentration as the ocean, preventing them from losing or gaining water through osmosis, but it is a necessity that means they smell of pee – so much so that, in Inuit legend, the shark is said to have arisen from the chamberpot of Sedna, goddess of the sea. The urea is also what makes them poisonous to humans when eaten fresh. If raw and untreated, the toxins in the flesh can render you ‘shark drunk’: giddy, staggering, slurring, vomiting. They become safe only if the meat is buried for several months and left to ferment, then hung out to dry for months more. Served in small chunks, and known as hákarl, it is considered, by some, a delicacy, and by others an abomination. Apparently it tastes like a very ripe cheese, left for a week in high summer in a teenage boy’s car.

The Greenland shark is slow, as befits a fish so venerable. At full speed and with strenuous effort, it moves somewhere between 1.7 and 2.2 mph. Although one of the two largest flesh-eating creatures in the sea, it has an astonishingly slow metabolism; in order to survive, a 200-kilo shark has to consume the calorific equivalent of one and a half chocolate digestives a day. They are both hunters and scavengers; they have been thought to hunt seals, perhaps inhaling them as they sleep on the surface of the water, but largely they eat whatever falls off the ice: reindeer, polar bears. The leg of a man was found in one shark’s stomach, but none of the rest of him. And they are slow even in the process of dying. Henry Dewhurst, a ship’s surgeon writing in 1834, saw a shark caught and killed:

When hoisted upon deck, it beats so violently with its tail, that it is dangerous to be near it, and the seamen generally dispatch it, without much loss of time. The pieces that are cut off exhibit a contraction of their muscular fibres for some time after life is extinct. It is, therefore, extremely difficult to kill, and unsafe to trust the hand within its mouth, even when the head is cut off. And, if we are to believe Crantz, this motion is to be observed three days after, if the part is trod on or struck.

They live deep down and lead secret lives. Although they have been seen at the water’s surface, they prefer to be close to the bottom of the ocean, where it’s dark and cold: they’ve been found as far down as 2200 meters: six Eiffel Towers deep. Nobody has ever seen one give birth; we have never seen them mate. Their invisibility to humans also means that we don’t know how endangered they are: they’re currently listed as ‘near threatened’, but they could be the most populous sharks in the world, or urgently at risk. We do know that for some time they were over-fished in large numbers – thirty thousand a year in the 1900s – in order to extract oil from their bodies. It was said that there were places in the Norwegian archipelago where houses painted in the emulsion made from the sharks’ liver oil shone bright even after fifty years: a paint like no other. We know, too, that because it takes 150 years for a female to be ready to breed, they replenish slowly. The Greek poet Oppian claimed that, when threatened with danger, a parent shark would open her cavernous mouth and conceal her young ones within. As this is, alas, unlikely to be true, we will need to take care of them ourselves.

Because they live so far below our ships and divers, we do not know where they swim. They come to the surface only in the places where it is cold enough, in the Arctic, around Greenland and Iceland, but they have been found in the depths near France, Portugal, Scotland. Scientists say they may be everywhere the ocean goes deep and cold: they could be far closer to us than we think.

I am glad not to be a Greenland shark; I don’t have enough thoughts to fill five hundred years. But I find the very idea of them hopeful. They will see us pass through our current spinning apocalypse, and the crash that will come after it, and they will see the currently unimagined things that will come after that: the transformations, revelations, the possible liberations. That is their beauty, and it’s breathtaking: they go on. These slow, odorous, half-blind creatures are perhaps the closest thing to eternal this planet has to offer.

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