有些海洋里有数以百万计的鱼 There are some seas where fish swarm in millions...
以及无边无际的浮游生物 and plankton blossoms in vast clouds
这里生物的数量是 其他任何海洋都无法比拟的 The sheer quantity of life here is unmatched anywhere in the oceans
这是地球上最富生产力的海洋 These are the most productive seas on earth
它们是季节性海域 They are the Seasonal Seas
季节性海域 环绕地球上温和的区域 The Seasonal Seas border the Temperate parts of the world,
那里的状况随时间而变化 where conditions change through the year
季节同样影响着海底世界 The seasons also affect the underwater world
太阳的力量随时都在改变 The power of the sun is constantly changing
北方的夏天里白天很长 ln the far north during the Summer there are long hours of sunlight,
但一到冬天便开始缩短 最后变成数周的永夜期 but in Winter that dwindles and eventually there can be weeks of darkness
夏天温暖而舒适 冬天却有剧烈风暴的折磨 The summers are warm and gentle, the winters racked by savage storms
这种情况下任何生命型态 都必须为生存而挣扎 ln conditions like this life of any sort has to struggle to survive
一月份北美新斯科细亚省 海岸边的塞柏岛 January on Sable lsland off the coast of Nova Scotia in North America
灰海豹成功地 穿越汹涌的海浪上岸 Grey Seals have managed to get ashore through the crashing breakers
这里的强风可持续数天 Gales here can blow for days on end
塞柏岛有地球上 最大的灰海豹族群 Sable lsland has the world's largest colony of grey seals
每年当天气正值最糟的时候 有十万只会来到这里繁殖 1 00,000 come here to breed each year, just when the weather is at its worst
雪上加霜的是，小海豹 To add insult to injury, the pups,
受哺乳18天后便被遗弃 having suckled for only 1 8 days are then abandoned
它们的母亲必须 回到海中为自己觅食 Their mothers must return to the sea to find food for themselves
还无法潜水的小海豹 As yet unable to dive, the pups are marooned
无依的仅靠身上肥厚脂肪存活 and sustained by nothing except their fatty blubber
它们要过5周才有能力游泳 lt will be five weeks before they are strong enough to swim,
但那时将是早春 而海洋中将充满食物 but by then it will be early spring and the ocean will be teeming with food
春天在五月降临苏格兰的海岸 By May, Spring has reached the coasts of Scotland
她更提前来到海底世界 Underwater it arrived rather earlier
三月时水温已回暖 神奇的转变同时展开 During March, the seas had warmed enough to trigger a magical transformation
这些是浮游植物群落 These are Phytoplankton, tiny floating algae,
微小的漂浮藻类小过针头 each much smaller than a pinhead
它们迅速的繁殖量远超过 And they multiply with amazing speed to produce more annual growth
陆上植物每年产量总和 60亿吨 than all the plants on land put together - 6 billion tonnes of it
这庞大的繁殖量 在数月内扩散地球表面海域 This immense bloom spreads across the face of the ocean
将广大区域染成浓密的绿 and within a couple of months turns vast areas of it a dense green
动物的生活反应这盛产的海洋 Animal life reacts to the blooming sea
虽然这些珊瑚虫看来像海葵 Although these polyps look like small anemones,
但它们正要改变型态 They're about to change into something else
当它们分离时 泄露出它们原是渺小平捿的水母 As they separate, they reveal themselves to be tiny, common jellyfish
它们体宽不到3公厘 They are less than 3 millimetres across
几周内它们会组成庞大的族群 Within a few months they will have assembled into vast swarms
桡足类是它们固定的食物之一 Minute copepods are part of their staple diet
它们在每年春天大量出现 并仰赖浮游植物维生 These appear every spring in vast numbers and graze on the Phytoplankton bloom
它们蠕动的脚造成水流 Their beating legs create currents that sweep the little algae
将海藻堆积到嘴边篮状的滤网 into the basket-like filters around their mouths
渺小的分子下 水变得黏稠 On this microscopic scale, water is so viscous that
使浮游植物无法逆水流而行 the Phytoplankton can't swim against the current
觅食时桡足类触须上的感应器 会发出危机伺伏的警讯 Whilst feeding, sensors on the copepod's antennae give warning of dangers ahead
以〖射照明发现 桡足类会在身后留下足迹 Lighting by lasers reveals that feeding copepods leave wakes behind them,
像是空中喷射机的烟雾 rather like jet trails in the sky
稍大的浮游掠食者 Slightly larger floating predators
能利用这些痕迹 找到它们的食物 are able to use these trails to find their prey
差一点点 但有些掠食者实在大到无法躲避 A close call - but some predators are simply too large to avoid
水母 Jellyfish!
它们也许看来脆弱又美丽 但它们却是致命的杀手 They may appear to be delicate as well as beautiful, but they are deadly hunters
铃铛状身体每一次柔弱的舞动 With every pulse of the delicate bells plankton-rich water
都将充满浮游生物的水 吸进它们蕾丝般的嘴里 is drawn into their lacy throats and pushed out again,
再将水推出 留下黏在薄膜上的桡足类 leaving behind copepods stuck to the membranes
一只几公分宽的荀麻水母 A single sea-nettle jellyfish only a few centimetres
能在一天内收集成千的桡足类 across can collect thousands of copepods in a day
因此这种庞然大物的杀伤力 是无法预测的 So the killing power of giants like these is hard to estimate
这种水母重约30公斤 Each of these jellyfish weighs up to 30 kilos
触须可伸展到8公尺长 and has tentacles stretching over 8 metres
但桡足类还面临着更大的危险 But there are even greater dangers awaiting the copepods
小水母在晚春时完全成熟 By the late spring the baby common jellyfish are fully grown
它们以数百万群集 形成数百公尺长的大族群 They gather in millions, forming immense swarms hundreds of metres long,
过滤所有通过它们的浮游生物 which filter out all the small planktonic animals in their path
尽管如此 桡足类庞大的数量 Nevertheless, there are such astronomic numbers of copepods
存活下来的还是 足以构成自己的族群 that enough will survive to form swarms of their own
一只在取暖的鲨鱼 A basking shark
这只8吨重的大鱼只吃浮游生物 This huge eight tonne fish feeds on plankton and nothing else
它每小时用鳃 过滤掉一千吨的海水 Every hour it filters a thousand tonnes of seawater through its gills
众多的鲨鱼 在浮游物最旺盛时出现 Numbers of these shark appear when the bloom is at its peak
顺着水流 游过浮游物最浓密的地方 and travel along those water currents where the plankton is thickest
然而浮游物的数量充足 Even so, the supply of plankton is so abundant
因此另一群动物也能共享大餐 that another group of animals' is able to share in the feast
那就是海底的动物 - animals that live on the seafloor
每一寸石头都为 无脊椎动物所覆盖 Every centimetre of rock is covered with invertebrates of some kind
海葵，海鞘及柳珊瑚 - anemones, sea squirts, Gorgonians,
都从水流中拦下浮游生物 all trapping plankton from the passing water
并非所有季节性海洋的生物 都依赖浮游生物 Not all life in the Seasonal Seas depends upon the plankton
这是英属哥伦比亚的早春 lt's early spring in British Columbia
海草已开始在冰水中生长 Seaweed has started to grow slowly in the cold water
当白天时间延长水温变暖 As the hours of sunlight increase and the water warms,
这些小植物变成一张大海草床 these small plants turn into great beds of bull kelp
这30公尺长的海滨 有充气的气囊 The immense 30 metre long strands have small gas filled floats
使它们能浮于水面 接收阳光的能量 which keep them high in the water within reach of the energy-giving sunlight
在南方阳光的力量更强 Further south the sunshine is more powerful,
于是在加州海岸 可以生长最大的海藻 so here, on the coast of California, the biggest kelp of all can grow
这是巨藻 而每年盛夏 This is giant kelp and by midsummer each plant
它们一天可生长近1公尺 is growing in length by nearly a metre a day
主茎干靠着一个小 却极有力的固着器 The main stem is fixed to the bottom 35 metres below
固定在海底35公尺下 by a small but immensely strong holdfast
完全生长的巨大植物 有100公尺长 Fully grown, these gigantic plants are a hundred metres long
形成一个广阔的海洋森林 and they form vast marine forests
这里是众多鱼群的庇护所 Great schools of fish find sanctuary here
这些是铁匠鱼 These are blacksmith fish
它们以浮游生物为食 只要觉得安全 They are plankton feeders and whenever it seems safe
它们就会到水中 浮游物最密集的地带觅食 they head off into open water to feed where the plankton is thickest
但只要有任何可能的危险 But at the first hint of danger...
它们就迅速躲回森林的保护 ...they rush back to the safety of the forest
鱼类不是唯一躲藏于此的生物 Fish are not the only creatures that shelter here
加州海獭也在水草森林中 安然地聚集休息 Californian sea otters gather in the kelp forest to rest and snooze in safety
为防止被拉进有掠食者游荡的 To prevent themselves being carried away into dangerous open water,
危险空旷海水中 where the big predators cruise,
它们用海草捆住身体 来固定方位 they anchor themselves by winding straps of kelp around their body
它们迟早需要去找食物 Sooner or later, they have to find food
而食物躺在 它们很下方的海床上 and that lies on the seabed a long way below them
海獭最多可在海底 Sea otters, however, can stay underwater for
停留10分钟，而这足以让它们 找到所需的甲壳类水生物 up to 1 0 minutes and that's ample time to find the shellfish they need
许多居住在这森林里的小生物 像是海胆便吃海草 Many of the smaller creatures that live in these forests, such as urchins,
但它们的数量若失去控制 便会造成严重损害 graze on the kelp and can seriously damage it if their numbers are unchecked
然而海獭以这些小生物为食 The sea otters, however, feed on some of these grazers
避免它们的数量过多 and prevent them getting too numerous
因此这些海獭是森林的守护者 So, in effect, the Sea Otters are the guardians of the forest
加州红鱼并不会破坏海草 Garibaldi fish do not, in fact, damage the kelp
反而它们会帮助除掉 lf anything, they help it by picking off tiny animals
附着在叶面上的小动物 that in places encrust the leaves
它们吃小型的寄生苔藓虫类 They graze on bryozoans, tiny colonial animals,
它们聚落像是 叶面上的白皮拼布 which build their colonies like a patchwork of white skins on the leaves
入夜后肉食性鱼类减少 When night falls there are fewer predatory fish around
苔藓虫类便从白防护罩下出现 and the bryozoans emerge from their white shelters
它们像珊瑚虫一样 在黑暗的掩护下 Now, just like coral polyps they start filtering out
开始过滤浮游物 the plankton under cover of darkness
它们不是此时出没的唯一动物 They are not the only animals to venture out at this time
这是只排骨虾，只有2公分长 它会吃海草 This is an amphipod, just two centimetres long and it does eat kelp
它对肉食者而言是很好的食物 ln turn, it is excellent food for many predators
它能像蜘蛛一样 吐丝来保护自己 To protect itself it produces silk, just like a spider,
也能将海草的两面缝在一起 形成屏障 and uses it to sew together two sides of a kelp frond and so form a shelter
这一只特别需要一个安全的家 她是个母亲 This one is in particular need of a secure home. She's a mother
它的腹部塞满超过50个幼苗 There are over fifty youngsters clustered on her abdomen,
所以它的住所变得有些拥挤 so her home is becoming somewhat cramped
它们很快的就能长大离开 所以母亲一有机会 They will soon be old enough to leave and now whenever she can,
就把它们踢出去看外面的世界 she kicks them out to get a taste of the outside world
破晓 Dawn
鳗鱼草成片生长在海草森林 及海岸间的浅滩上 Beds of eel grass grow in the shallows between the kelp forest and the shore
一只海狮在此得到保护 A harbour seal has found sanctuary here,
正因一晚艰辛的觅食而休憩中 and is sleeping after a hard night's foraging
但不会太久 But not for long
一只公海豹发出起床号 A male seal gives a wake up call
更多的海豹 从各方向被吸引而来 More seals are attracted from all directions
六月时年轻公海豹 lt's June, the time when young male harbour seals
开始它们奇特的求偶展示 start their strange mating displays
聚精会神地聆听彼此的呼声 One listens attentively to the grunting noises made by the other
这些叫声几乎是断定 These calls are almost certainly a way of establishing
谁将处于优势的方法 which of the two will be dominant
但如果它们的体型与经验接近 But if the animals are closely matched in size and experience
这件事就无法靠呼声决定 两个对手必须奋战一场了 - grunts won't settle the issue, the rivals will have to come to blows
海豹可以是十分残暴的 And seals can be surprisingly violent
一个月后繁殖期就将开始 ln a month's time the breeding season will start
而争斗也更加严重 and then fights will be in earnest
但这些在穷夏的交手 是无伤大来的 But now in mid-summer these exchanges are harmless
它们只是在嬉戏 They're just playing
许多藏身在海草里的生物 Many of the creatures that shelter in the kelp
必须在夜晚外出觅食 have to venture out in order to feed
小灯光鱼就是其一 A bat ray, for one
虽然出乎意料 但海中的沙陆 Unlikely though it seems, the sandy floor of the open sea is,
对灯光鱼来说 是个丰富的觅食地 for the bat ray, a rich feeding ground
食物就藏在沙中 There is food hidden within the sand
而灯光鱼有 能找到它的特别技巧 and the bat ray has a special technique for finding it
它会喷水来吹开沙砾 小型的无脊椎动物就现身了 lt uses jets of water to blow the sand aside and expose small invertebrates
一只海草鲈鱼 在一旁等着分一疷羹 A kelp bass hangs about alongside, waiting for scraps
其他的狩猎者也正四处搜寻 Other hunters are also on the prowl
扇尾鲽鱼 The fan tailed sole
穴道中住着螳螂虾 There are mantid shrimps here, living in tunnels
但饥饿迫使它们外出觅食 But once again, hunger compels them to venture into the open
当然那是种з注 That, of course, is a gamble
它们不是找到食物 They will either eat...
就是被吃掉 ...or be eaten
这是杰那罗海虫舌虫俞 A sea slug, called Janolus
它的颜色显示它有毒 它的毒性 lts colours suggest that it's poisonous and so it is,
只对另一种海虫舌虫俞无效 to everything except another kind of sea slug
这是肉食性的那维克斯 the predatory Navanax
那维克斯跟随着 杰那罗留下的黏液痕迹 Navanax pulls itself along the trail of slime that Janolus leaves behind it
被抓时 杰那罗会砝成一颗球 Once caught, Janolus rolls into a ball...
那维克斯只能吃到一些黄触角 All Navanax gets is a few yellow tentacles
而杰那罗会被水流冲到安全处 And Janolus is swept to safety by the current
时值穷夏时节 此时阳光最为强烈 lt's now mid-summer and the sun is shining at full strength
上升的温度提醒大西洋龙虾 The increasing warmth is the cue for an Atlantic lobster
开始它的长途旅行 to start on a long journey
它在250公尺的深处度过冬天 完全不受暴风的威胁 She has spent the winter 250 metres down, far beyond the reach of the storms
但那里十分寒冷 它必须找到较温暖的水 But it was cold down there and now she needs to find warmer water,
所以它朝着浅滩前进 so she's marching towards the shallows
然而那却是在150公里远处 They, however, are 1 50 kilometres away
走了一个月后 它终于来到它最爱的沙陆 After a month of walking she finally arrives at her favoured sand bank
但它并非首先到达的 But she's not the first here
成群的龙虾已在沙中定居 Dozens of other lobsters have already dug themselves homes in the sand
而它们并不会 交出自己的栖息地 and they don't intent to surrender them to newcomers
争斗的关键在于体型的大小 Size counts for everything in these battles
新来的急需要一个洞穴 由于它重约7公斤 The new arrival is in urgent need of a pit and since she weighs a hefty 7 kilos,
它获胜的机率很大 she stands a good chance of getting one
它嬴了 She's won
这些重要的斗争会持续两个月 These battles continue for the next two months and they're crucial,
因为这些母亲需要 for the females must have both shelter
同时有屏障及温水 来照顾它们的后代 and warm water if they're to raise their young
过去7个月内 这里每只母龙虾 For the last seven months, each of these females has been carrying
都身怀约2万个受精卵 around about twenty thousand fertilised eggs
但它们的难题在于完成使命 But their task is approaching its end
浅滩的温暖加速了卵的生长 The warmth of the shallows is speeding the eggs' development
再过两个月卵就能孵化了 Two more months and the eggs are ready to hatch
它们一开始不太会游泳 At first, they're not very good at swimming
但几分钟内这些幼儿 就能任意活动了 But within a few minutes the babies are able to set off in a purposeful way
每年此时海中 到处是动物的幼儿 At this time of year the sea is full of larval animals
这是只一天大的龙虾 - this one is a 1 day old lobster
而这是只3星期大的螃蟹 正要开始它海底的生活 And this ... a 3 week old crab, just ready to start its life on the sea floor
它的脚第一次着地 lts feet touch the bottom for the first time
它此时还是个素食者 特别喜爱海莴苣 At this stage in its life it's a vegetarian, with a taste for sea lettuce
成长时它会不断脱皮 换上更大更厚的皮肤 As it grows, so it will repeatedly moult and expand into a bigger, thicker skin
它可能会被吃掉 但它如果能存活5年 The chances are it will be eaten, but if it survives for five years
它会变成壮观的盔甲巨兽 it will have become a magnificent armoured giant
它现在吃肉，而特殊的适应力 使它能在黑暗中猎食 Now it eats meat and special adaptations enable it to hunt in the dark
它接合的脚上布满感应器 lts jointed feet are covered in sensors,
能侦测到周围微小的化学变化 which detect the slightest chemical change in its surroundings
而当它穿梭在黑暗中时 它的脚可以尝到沙的味道 And as it walks through the darkness its feet can, literally taste the sand
一旦它找到适合的食物 As soon as it finds suitable food,
它会把它放到有力的υ上 it passes it forward to its powerful crushing claws,
使进食的动作变得容易 which make light work of the soft flesh
这些υ子也是防卫的好工具 And those claws are also very useful for defence
一只1.5公尺长的章鱼经过 A one and half metre long common octopus glides by
这只喷射巨兽力量很大 也很聪明 The jet propelled giant is both powerful and very clever
只要有章鱼在的地方 即使是螃蟹也会有危险 With octopus about, it's risky for even a crab to be in the open
就算一片漆黑，章鱼的眼睛 对轻微的动作还是很敏感 Even in the dark, the octopus's eyes are sensitive to the slightest movement
对付像这样的掠食者 螃蟹的υ也是无用的 Against a hunter like this, the crab's claws are useless
东南阿拉斯加的夏末 Late summer in South East Alaska
水温正回升中 酱虾在水面集结成群 The water is still warming and mysid shrimp are swarming near the surface
从宽阔的太平洋回到海岸 lt's a final feast for Pacific salmon,
这是太平洋鲑鱼的最后飨宴 returning to the coast from the open Pacific
它们朝近海去繁殖 而它们的为数众多 They are heading inshore to breed and they arrive in huge numbers
它们必须往远处上游产卵 They have to swim far up the rivers to spawn,
但这条河的水位还太低 but this river's level is still too low
它们必须等到 有雨水能让水位升高 - they'll have to wait until rain causes it to rise
目前它们被困在海中 So, for now they are trapped in the sea,
靠近海岸处 最糟糕的地方 close to the shore, the worst place to be
一只3公尺长的鲑鱼鲨 与大白鲨是近亲 A three metre long salmon shark, a close relation of the great white
它已察觉到邻近鲑鱼传来的 微小电子讯息 This one has sensed minute electrical signals from the salmon nearby
鲨鱼可以维持体温 高于 Shark can maintain their blood temperature at a higher level
周鉰海水的状态 than the surrounding sea water
这表示它们有体力能迅速动作 And that means they have the energy to be quick
甚至比鲑鱼还快 Quicker even than salmon
加拿大温哥华岛的早秋 南方600里处 Early autumn in Vancouver lsland in Canada, 600 miles to the south
海水的温度缓慢的下降 The ocean temperature is slowly dropping
海底40公尺的地方 Forty metres below the surface,
今年的小鲱鱼正在吃 最后的夏末浮游生物 this year's baby herring are feeding on the last of the summer's plankton
它们的举动引来天上的注意 Their movements attract attention from the skies above
海鸥无法潜水 所以此刻鱼群仍算安全 Gulls can't dive, so for now the fish are still safe
但有些鸟能潜水 But there are birds which can dive
海鸦等鸟类 毫不费力地潜入鱼群中 Auklets and murres swim effortlessly down beneath the school
惊惧的鲱鱼被驱赶至水面 The panic herring a force towards the surface
旋转的鱼群聚集成一个 庞大的防御球 They gather into a giant defensive ball of swirling fish
这股骚动吸引了 岩石中的黄尾魔鬼蓑 The commotion attracts Yellowtail rockfish
它们也是猎食者 They too are hunters
趁火打劫的鱼打散了鲱鱼群 The marauding fish scatter the herring
持续的攻击使大球 分成许多小群体 Repeated attacks split the ball into numerous smaller groups
现在潜水者 可让困惑的 Now it's easier for the divers to keep
鱼群留在水面 the confused fish penned at the surface
如此就连海鸥都能得到它们 and there even the gulls can get at them
从各方向被攻击 小鱼们没有丝毫的胜算 Attacked from all sides, the little fish have virtually no chance
越来越多的潜水者被引来 More and more divers are attracted to the scene
它们不断骚扰数量骤减的鲱鱼 They harry the shrinking numbers of herring right down
直到最后一只为止 to the very last individual
体积超大的掠食者也在此徘徊 Far bigger predators cruise here, too
太平洋白侧海豚 Pacific white-sided dolphin
但海豚多数在夜间觅食 But the dolphin are mainly nocturnal hunters
白天它们专心于社交 - during the day they concentrate on socialising
它们会表演释放成串的泡泡 也会玩游戏 They display by releasing streams of bubbles and they play games...
例如传递海草 ...games like pass the seaweed, for example
8个月前苏格兰西岸的冬天 Exactly eight months ago in the winter off the west coast of Scotland
一个卵被产下 并被菺善的缠在海草上 an egg was laid - and securely fixed to a strand of kelp
里头有个小胚胎开始成长 lnside, a tiny embryo started to develop
在坚硬的蛋壳保护下 它度过冬天最糟的暴风 Protected by the tough egg case, it endured the worst of the winter storms
夏天时它已成熟一半 By summer it was half grown
终于在秋天尾声时 它准备好要孵化 Now at last, in the late autumn - it's nearly ready to hatch
一只成形的迷你鲨鱼现身 A fully formed miniature shark swims free
今年的浮游生物即将死去 但年轻的狗鲨 This year's plankton will soon die but the young dogfish
成长完善 已能立即捕猎较大的动物 is so well developed that it can't hunt immediately for larger prey
白天渐渐变短 The days are getting shorter now
英属哥伦比亚的海水开始变冷 ln British Columbia the water begins to chill
这只长相怪异的生物 正试着从海草中找寻食物 This bizarre looking creature is searching through the kelp for food
这是梅黎贝海虫舌虫俞 This is Melibe - the hooded sea slug
它用网状的头抓浮游物 lt catches plankton with its net-like head
冬天来临浮游物变得稀少 As winter approaches plankton is becoming scarce,
但梅黎贝是勤奋的搜索者 but Melibe is an assiduous searcher
它会游泳 lt can swim
它离开去寻找更好的觅食点 lt flaps away to look for a better feeding spot
但它的搜寻越来越艰难 But its search is becoming increasingly difficult
往后两周内 多数的浮游物都将消失 Within the next two weeks most of the plankton will have disappeared
阳光变得更微弱 As the sunlight becomes ever more feeble
海草开始死亡 渐渐地腐烂消失 - the kelp starts to die, gradually rotting away to nothing
冬天即将降临 Soon it will be winter
但往南9千里 太阳正在一个新的春日升起 But 9,000 miles to the south the sun is rising on a new spring day
南半球同样也有不同的气温区 The southern hemisphere too has Temperate regions
此刻浮游物正在 塔斯梅尼亚繁衍 - and now the plankton is beginning to bloom around Tasmania
如同北方一样 南方的季节性海洋 Just as in the north, the Southern Seasonal Seas
也有茂盛的绿水区 also have areas of rich green water...
有它们自己的海草森林 ...with their own kelp forests
及它们的浮游生物族群 ...and their own swarms of plankton
有些在此域的生物 只居住在南半球 Some of the inhabitants of these seas live only in the southern hemisphere
这是其中之一，手鱼 靠变化过的鳍漫步着 This is one of them - the handfish - that strolls around on modified fins
但必要时它也能使用尾的力量 But when needs must - it can resort to tail power
每个夏季都有访客前来 塔斯梅尼亚的浅滩 Every summer visitors come to the shallows around Tasmania
这些是奥洲乌贼 约有半公尺长 These are Australian squid - about half a metre long
它们到此繁殖 They are here to breed
较大的公乌贼会以表现 The larger males compete for the attentions of a female
来争夺取异性的注意力 更手足舞蹈彼此比较 displaying towards her and to one another by putting on a ballet,
期间它们还会不断改变颜色 during which they continually change the colour of their costumes
最后它们会配对 Eventually they form pairs
公的会给母的一团精液 A male passes a packet of sperm across to the female
卵受精后 它们会被放置在 After the eggs have been fertilised, they are deposited in tough,
对其他生物具毒性 而坚固有弹性的蛋壳内 rubbery egg cases that other creatures find poisonous
3周内胎儿就准备好孵化 Within three weeks the babies are ready to hatch out
它们已经可以改变颜色 They are already able to change colour
但还不太会游泳 - but they're not quite so good at swimming
这里有另一种动物 是尽责的父母 There is another animal here that is a rather more devoted parent
这是一只公海龙 This is a male leafy sea dragon,
是海马外形精致的远亲 an exquisitely decorated relative of the sea horse
它随身带着配偶的卵 He is carrying his partner's eggs around with him
这些会是掠食者极营养的点心 They would be a highly nutritious snack for any predator that found them
但那绝非易事 因为卵都附着在 But that's not easy because the eggs are attached
这个父亲 伪装完美的身体上 to their father's perfectly camouflaged body
没有比这儿更安全的地方了 They could scarcely be in a safer place
往北1万里 冬天在11月降临 By November, 1 0,000 miles to the north, winter has arrived
挪威现在每天只有 少于5小时的白天 Norway now gets less than 5 hours of daylight in every twenty four
温度急速下滑 The temperature is falling rapidly
任凭天气严寒 海水并不空旷 But despite the cold, the sea is far from deserted
每年冬天有5亿吨的成年鲱鱼 Every winter, 500 million tonnes of adult
在深海里寻求庇护 herring seek shelter in these deep waters
它们会停留4个月 完全依赖夏天 They will stay here for four months, living entirely on the fat
浮游生物大餐中 储存下来的脂肪 they accumulated during the summer feasts of plankton
它们不是唯一在此的 But they are not alone...
海怪 Orca's his small pod is part of a population
它属于500只杀人鲸的一部份 of some five hundred killer whales
专门猎杀北大西洋鲱鱼 that specialise in hunting North Atlantic herring
靠回音定位的侦测 Using their echo-location they have detected a shoal
它们找到50公尺以下的鲱鱼群 of herring 50 metres below them
足够的氧气使其能潜水10分钟 With enough air for a 1 0 minute dive...
它们游到鲱鱼之下 将它们驱赶向上 they swim deep below the herring and drive the fish upwards
它们气囊的气体扩张释出 Bubbles stream from the rising fish
形成连串的气泡 as gas in their swim bladders expands and escapes
想要捕捉一只健康的鲱鱼 对海怪而言并不觉得容易 Even an orca finds it difficult to catch a healthy herring
但它们有独特的致命武器 But they have a devastating weapon all their own
它们用尾巴所造成的 一波波水压来打击鱼群 They use their tail to club the fish with waves of water pressure
然后就只需收集昏迷的伤鱼了 鲱鱼彻底失败 Then it's simply a matter of collecting the stunned casualties
在接下来的4个月内 而海怪及海鸟 The herrings have no chance and both orca and gulls will eat as much as they can
每天都会尽情享用盛宴 - every day for the next four months
但仍有许多鱼类在此过冬 有超过50亿只 But there are so many fish wintering here, over 5 billion individuals,
以致于那些损失变得微不足道 that the losses are almost unnoticeable
冬天的气候也许猛烈 Violent as this Winter weather may be
季节性海洋的更新 是不可或缺的 - it's essential for the renewal of the riches of the Seasonal Seas
宽阔的远洋中 汹涌的海水将滋养物从深处翻动 Out in the open oceans, the surging waters stir up nutrients from the depths
冬天结束之前 季节性海洋将再次充满矿物质 By the end of winter the Seasonal Seas will be full of minerals once more,
准备迎接太阳的回归 及下次盛大的浮游生物繁衍 ready for the return of the sun and the next great plankton bloom