Level 5 Reading 6A

Reading 6A

阅读6A

QUICKSILVER Prized for sushi, the fast and powerful Atlantic bluefin tuna is being relentlessly overfished. Kenneth Brower goes in search of the story behind the king of all fish. One moment the undersea scenery is an empty blue cathedral, the sun an undulating hot spot in the waves overhead. Its beams shine down as if from stained glass. The next moment the ocean is full of giant bluefin tuna, the largest measuring over four meters and weighing three-quarters of a ton. In the sea's refracted sunlight, their pale sides flash and sparkle like polished shields, and their long, curved fins cut the water like swords. Quick-moving tail fins drive them forward at 10 knots, with bursts of speed to 25. And just as suddenly, they are gone—the ocean empty again. Here and there, a small galaxy of scales marks where a bluefin swallowed a herring. The victim's scales swirl in the turbulence of the departed tuna, now heading off at high speed. The King of Fish Tunas are streamlined to perfection and equipped with cutting-edge biological gear. The characteristics that distinguish them include great size, great range, efficient swimming, warm bodies, large gills, excellent regulation of heat, rapid oxygen uptake, and a cleverly adapted heart. All of these reach their peak in the bluefin—"the king of all fish," as Ernest Hemingway described them after seeing Atlantic bluefin off the coast of Spain. The three species of bluefin—the Atlantic, Pacific, and southern— are found in all the oceans except around the North and South Poles. The bluefin is a modern fish, yet its relationship with humanity is ancient. Japanese fishermen and the Haida people of the Pacific Northwest have caught Pacific bluefin for more than 5,000 years. Stone Age artists painted Atlantic bluefin tuna on the walls of Sicilian caves. Iron Age' fishermen watched for the arrival of bluefin schools at their Mediterranean spawning grounds, and ancient coins from that region have images of giant bluefin on them.

水银 以寿司而闻名的快速而强大的大西洋蓝鳍金枪鱼正在被无情地过度捕捞。 肯尼斯·布劳尔（Kenneth Brower）探究了鱼之王背后的故事。 刹那间，海底风景是一座空荡荡的蓝色大教堂， 太阳在头顶的波浪中形成了一个起伏的热点。 它的光束像彩色玻璃一样闪闪发光。 下一刻，大海里满是巨大的蓝鳍金枪鱼， 最大的一个超过四米，重四分之三吨。 在海水折射的阳光下， 它们苍白的侧面像抛光的盾牌一样闪闪发光， 它们弯曲的长鳍像剑一样划破水面。 快速移动的尾翼以10节的速度推动它们前进，速度可达25节。 突然间，它们消失了——大海又变空了。 在这里和那里，一个小的鳞片星系标记着蓝鳍金枪鱼吞下鲱鱼的地方。 受害者的鳞片在离去的金枪鱼的湍流中旋转， 现在正高速前进。 鱼之王 金枪鱼被精简到完美，并配备了尖端的生物装备。 区别它们的特征包括大尺寸， 范围广，游泳效率高，身体温暖，鳃大， 出色的热量调节、快速的氧气摄取和巧妙适应的心脏。 所有这些在蓝鳍金枪鱼中都达到了顶峰——“所有鱼类之王” 正如欧内斯特·海明威在西班牙海岸看到大西洋蓝鳍金枪鱼后所描述的那样。 三种蓝鳍金枪鱼——大西洋、太平洋和南方-- 在除北极和南极以外的所有海洋中都有发现。 蓝鳍金枪鱼是一种现代鱼类，但它与人类的关系由来已久。 日本渔民和太平洋西北部的海达人 捕捞太平洋蓝鳍金枪鱼已有5000多年的历史。 石器时代的艺术家在西西里洞穴的墙壁上画了大西洋蓝鳍金枪鱼。 铁器时代的渔民们在地中海产卵场等待蓝鳍金枪鱼鱼群的到来， 该地区的古代硬币上有巨型蓝鳍金枪鱼的图像。

But this relationship with humans has lately been detrimental to the bluefin. They are today among the most overfished species, largely because people are prepared to pay a high price for them. One medium-sized bluefin in Japan brings in between $10,000 and $20,000, depending on quality. In 2019 a 288-kilogram bluefin sold for over $3 million at the Tokyo fish market. It is a startling measure of what the bluefin tuna is up against if more than a handful are to see the 22nd century. Tagging a Giant The day dawned over Cape Breton, Nova Scotia, as Captain Dennis Cameron and his crew left port in his fishing boat. Along the back wall of the boat's cabin, fishing rods were racked and ready. In the open ocean ahead, fishermen catch the biggest bluefin tuna in the world. Cameron knows the history of the local fishing industry well. "We didn't fish tuna," he says of his father's generation. "Tuna fishing was more of a sport. Years ago they used to call it 'horse mackerel.' It was cat food back then, or fertilizer." To the right, we passed the big island of Cape Breton; to the left, a small island with a scattering of white houses, including the one in which Cameron grew up. The waterfront—crowded with fishing boats in the 1920s—is now deserted. So it goes in fishing communities worldwide. The ocean is dying, and overfishing is the primary cause. That day, however, we were on a different kind of fishing trip: We had come to tag and measure bluefin, not to kill them. While Cameron steered toward deep water, Steve Wilson, a Stanford University researcher who works with the Tuna Research and Conservation Center (TRCC), checked the satellite tags he hoped to attach to bluefin that day.

但这种与人类的关系最近对蓝鳍金枪鱼不利。 它们是当今被过度捕捞的物种之一， 这主要是因为人们愿意为它们付出高昂的代价。 日本一只中等大小的蓝鳍金枪鱼 根据质量的不同，收入在10000到20000美元之间。 2019年，一条288公斤重的蓝鳍金枪鱼在东京鱼市以300多万美元的价格售出。 这是对蓝鳍金枪鱼所面临挑战的惊人衡量 如果不止少数人看到22世纪。 标记巨人 新斯科舍省布雷顿角黎明时分， 当丹尼斯·卡梅伦船长和他的船员乘坐他的渔船离开港口时。 沿着船舱的后墙，钓竿已经装好，准备就绪。 在前方的开阔海域，渔民们捕捞到了世界上最大的蓝鳍金枪鱼。 卡梅伦非常了解当地渔业的历史。 “我们没有钓金枪鱼，”他谈到他父亲那一代人时说。 “金枪鱼捕鱼更像是一种运动。 多年前，人们常称之为“竹荚鱼” 那时候是猫粮，或者是肥料。" 向右，我们经过了布雷顿角大岛； 左边是一个小岛，上面散落着白色的房子， 包括卡梅隆成长的那个地方。 20世纪20年代，海滨挤满了渔船，现在却空无一人。 世界各地的渔业社区也是如此。 海洋正在死亡，过度捕捞是主要原因。 然而，那天我们进行了一次不同的钓鱼之旅： 我们是来标记和测量蓝鳍金枪鱼的，不是来杀死它们的。 当卡梅伦转向深水时，斯坦福大学研究员史蒂夫·威尔逊 他与金枪鱼研究和保护中心（TRCC）合作， 检查了他希望当天贴在蓝鳍金枪鱼身上的卫星标签。

Nine kilometers offshore, drifting with three fishing lines in the water, we had a strike. Sheldon Gillis—Captain Cameron's assistant—fought the fish. It took twenty minutes until the fish made its first appearance, with Gillis reeling in furiously each time the tuna gave him the chance. After another 20 minutes came the loud, slapping bang of tail fin against the boat. The tuna was hauled aboard through a specially designed "tuna door," then laid on its side on a padded mat, perfectly still and enormous. Out of water, it looked like some kind of wonderful machine, biologically inspired and poured of living metal. Wilson and his tagging team worked quickly and efficiently. A wet black cloth went over the eyes, and a green hose went in the mouth, pumping seawater past the gills. The fish measured three meters long a length that corresponds to a weight of around 550 kilograms. In nearly 20 years of work, it was the third biggest bluefin ever tagged by the team. Wilson then stuck a harmless dart into the fish to hold a satellite tag, and his assistant cut a thin piece of a fin for DNA analysis. Then the two men at the tail lifted their end of the mat, and the tuna plunged back into the water. Two flicks of its tail fin and it was gone. On his laptop the night before, Wilson had programmed the satellite tag to release in nine months, after which the tag will rise to the ocean's surface and send information about the tuna's movements to TRCC's home base in California. Bluefin Migration Stanford University professor Barbara Block, a preeminent scholar of the bluefin, runs TRCC out of Hopkins Marine Station in collaboration with the Monterey Bay Aquarium next door. The walls and cabinets of Block's lab are covered with charts, maps, and illustrations from scientific journals. One poster shows a graph of the spawning population of Gulf of Mexico bluefin above a similar graph for Mediterranean bluefin. Both populations are represented by lines that are diving toward the bottom of their graphs. They have plunged past the dotted line representing sustainable yield and are headed for zero. The locations of bluefin, as reported by the many satellite tags over the years, are represented by small circles in different colors. The western bluefin—represented as reddish-orange circles— pack the Gulf of Mexico, their spawning grounds. From there they spread eastward into the western Atlantic and cross over to the eastern Atlantic, reaching all the way to Portugal and Spain. The eastern bluefin—represented as white circles— fill their Mediterranean spawning grounds, and from there spread westward, crossing over to the western Atlantic, covering the coastal waters of the United States and Canada. The fact of this mixing has been firmly established by Block, other taggers, and DNA researchers. The best estimates today are that around half of the bluefin caught off the eastern shores of North America were spawned in the Mediterranean. However, until recently these tuna if caught in the west— have been mistakenly counted as fish of western origin. The discovery of the mingling of the two populations is making more accurate fisheries management possible. Uncertain Future But an alarming lesson lies hidden at Hopkins Marine Station. Established by Stanford University in 1892, it was the first marine lab on the West Coast of the United States. Its old buildings, like the abandoned cannerics immediately to the east, were built during the age of sardines, which ended 60 years ago due to overfishing. By the 1980s sardine populations had started to come back a little, but now they are falling again. In a building near Hopkins are three large, waist-deep tanks, where a number of Pacific bluefin tuna are swimming. Block and her colleagues practice their tagging techniques here on fish like these. To maintain healthy populations, the bluefin tuna will need wise management assisted by good science. Here in Monterey, the consequences of the opposite are clear. Directly below the tanks of bluefin are the ruins of cannery piers that reach out into the bay for sardines that are no longer there.

离岸九公里，三条钓线在水中漂流，我们罢工了。 Sheldon Gillis——卡梅隆船长的助手——与鱼搏斗。 这条鱼花了二十分钟才第一次出现， 每次金枪鱼给他机会，吉利斯都会疯狂地蹒跚而行。 又过了20分钟，尾鳍砰的一声拍打着船。 金枪鱼是通过一个特别设计的“金枪鱼门”拖上船的 然后侧身躺在垫子上，一动不动，巨大无比。 出水后，它看起来像某种神奇的机器， 生物启发和浇注的活金属。 Wilson和他的标记团队工作快速高效。 一块湿漉漉的黑布遮住了眼睛，一根绿色的软管伸进了嘴里， 把海水抽过鳃。 这条鱼有三米长 长度相当于约550公斤的重量。 在近20年的工作中，它是该团队标记的第三大蓝鳍金枪鱼。 威尔逊随后将一支无害的飞镖刺入鱼体内，以固定卫星标签， 他的助手切下一小片鳍进行DNA分析。 然后，尾部的两个人抬起垫子的一端， 金枪鱼又跳进了水里。 它甩了甩尾鳍两下，就不见了。 前一天晚上在他的笔记本电脑上， 威尔逊已经将卫星标签编程为在九个月内发布， 之后，标签将上升到海洋表面 并将金枪鱼活动的信息发送到TRCC在加利福尼亚州的基地。 蓝鳍金枪鱼迁徙 斯坦福大学教授芭芭拉·布洛克是一位杰出的蓝鳍金枪鱼学者， TRCC与隔壁的蒙特利湾水族馆合作，在霍普金斯海洋站外运营。 布洛克实验室的墙壁和橱柜上挂满了图表、地图、， 以及科学期刊上的插图。 一张海报展示了墨西哥湾蓝鳍金枪鱼产卵种群的图表 上图为地中海蓝鳍金枪鱼的类似图表。 这两个群体都用线条表示 它们正朝着图表的底部俯冲。 它们已经跌破代表可持续产量的虚线，正朝着零的方向发展。 多年来，许多卫星标签报告了蓝鳍金枪鱼的位置， 由不同颜色的小圆圈表示。 西部蓝鳍金枪鱼——以红橙色圆圈表示-- 将它们的产卵地墨西哥湾打包。 从那里，它们向东扩散到西大西洋 然后横跨大西洋东部， 一路到达葡萄牙和西班牙。 东方蓝鳍金枪鱼——以白色圆圈表示-- 填满它们的地中海产卵场，并从那里向西扩散， 横跨大西洋西部， 覆盖美国和加拿大的沿海水域。 Block、其他标记者和DNA研究人员已经牢固地证明了这种混合的事实。 目前最好的估计是，大约一半的蓝鳍金枪鱼 在北美东海岸捕获的鱼类在地中海繁殖。 然而，直到最近，这些金枪鱼如果在西方捕捞-- 被误认为是源自西方的鱼类。 发现两个种群的混合 使更精确的渔业管理成为可能。 未卜的未来 但霍普金斯海洋站隐藏着一个令人担忧的教训。 斯坦福大学于1892年成立， 这是美国西海岸的第一个海洋实验室。 它的旧建筑，比如东边废弃的戛纳， 它们是在60年前因过度捕捞而结束的沙丁鱼时代建造的。 到了20世纪80年代，沙丁鱼的数量开始有点回升， 但现在它们又在下跌。 在霍普金斯附近的一栋建筑里，有三个齐腰深的大坦克， 许多太平洋蓝鳍金枪鱼正在那里游泳。 布洛克和她的同事们在这样的鱼身上练习他们的标记技术。 为了维持健康的人群， 蓝鳍金枪鱼需要明智的管理，并辅以良好的科学。 在蒙特雷，相反的后果是显而易见的。 蓝鳍金枪鱼水箱正下方是罐头码头的废墟 它们伸到海湾里，寻找已经不在那里的沙丁鱼。

♪

♪