地球上有一种力量 大到足以搬动海洋 There is a force sufficiently powerful to move the oceans of this world
这种力量 不存在地球上 lt is a force, not of this earth
月球大到足以造成地心引力 The moon is large enough to generate gravity
足以从三万两百里远的地方 and with sufficient force to pull on the earth,
牵动着地球 two hundred and thirty thousand miles away
当月球绕地球运行时 她的引力横扫过我们星球的表面 As the moon orbits the earth its gravity sweeps across the face of our planet
她的力量增强时 能使海水剧烈隆起 lts power drags a great bulge of oceanic water in its wake
也就是涨潮 - the rising tide
巴西的亚马逊河 The River Amazon in Brazil
在特定时节中月球与太阳 On some special days the gravitational forces
的地吸引力同时作用 造成异常强大的影响 of the moon and the sun pull together - to extraordinary effect
成形中的潮浪 被推向内陆200里 A growing tidal wave from the ocean is being forced two hundred miles inland
这是海啸 This is a tidal bore
幸运的是海啸并不常见 Fortunately tidal bores are rare,
但月球的确在地球的海洋上 造成强大的潮流 but the moon does create strong tides out in the world's oceans,
日复一日到年复一年 on every day of the year
新斯科细亚省芬地湾 The Bay of Fundy, in Nova Scotia
这里的潮浪是世上最强的 The tides here are the largest in the world
对海洋生物造成显著的影响 制造了一个富足的聚食场 and have a profound effect on marine life, creating a rich feeding ground
这个盛宴吸引了一些 地球上体积最大的食客 A feast that attracts some of the largest diners on the planet
座头鲸 Humpback whales
但它们并不是鲱鱼最大的威胁 But they are not the biggest threat to the herring
这些是脊鳍鲸 These are finback whales
重70吨 是世上第二大动物 At seventy tonnes - the second largest animal on earth,
但完美的流线体型 使它成为速度最快的鲸鱼 but so beautifully streamlined that it is the fastest of the great whales
速度与庞大体积的结合 This combination of speed and immense size
使脊鳍鲸成为凶恶的鱼群猎手 makes the finback a voracious hunter of schooling fish
芬地湾能吸引为数众多的鱼群 夏季时 The Bay of Fundy can attract so many fish, that during the summer,
每天有500只 壮观的鲸鱼在此觅食 as many as five hundred of these magnificent whales hunt here every day
而浪潮汹涌的地方最利于觅食 The feeding is best where the tides run strongly
所以鲸群向海湾前进 So the whales move further into the bay,
跟随着潮浪寻找鱼群 following tidal rips and searching for fish
它们的行动 都在水剃鸟的监视中 Their movements are closely watched by flocks of Cory Shearwaters
只要鲸鱼朝鱼群潜入 As the whales dive down toward the fish
越来越多的鸟就会聚集 迫切地想分点食物 - more and more birds gather, anxious to pick up scraps
流动的潮浪也许 能为鲸群带来飨宴 The flowing tide may provide a feast for the whales,
但它很快地就会转向 but before long it will turn
短短6小时内 上千亿吨的水 ln just six hours, one hundred billion tonnes of water
就会流出海湾 will flow out of the bay
海水位会降低15公尺之多 The sea level falling by as much as 1 5 metres
留下大片的泥沙 and exposing vast tracts of mud... and sand
乍看像是块脊地 没有任何生命迹象 At first sight a barren place, entirely devoid of life
事实上潮湿的沙里 充满微小生物 ln fact, the damp sand is packed with microscopic life
在沙底世界觅食的底下动物 - the meiofauna, feeding in a sandy underworld,
完全不受退潮的影响 quite unaffected by the departure of the sea
但这小世界里的生命 并非完全美好 But life is not all roses in this miniature world
一只北奥洲的喷沙蟹 它捕食底下动物 A sand bubbler crab - in Northern Australia - it hunts meiofauna
只有几公分宽的喷沙蟹 动作十分快速 Just a centimetre across, the sand bubbler works at breakneck speed,
将沙砾塞进嘴里 passing sand grains into its mouth,
过滤出所有的底下动物 并将垃圾踢到一旁 filtering out all the meiofauna and kicking aside the waste
它们会将自己洞穴周围 1公尺的沙全部清干 The crab will clean every grain of sand within a metre of its burrow
持续的练习使它们的倒退技术 堪称全自然界之冠 Endless practise for the best back heel in the Natural World
它们的动作迅速 因为它们只能过滤潮湿的沙 The crabs work fast because they can only sieve when the sand is damp
令人称奇的是 它们能在几小时内 Remarkably, they work the entire surface of the beach
趁着退潮时 过滤沙滩上所有的沙 within just a couple of hours of the tide retreating
接着它们便退回洞穴 静待下一次涨潮 Then they simply return to their burrows and await the next tide
在水中下降的浪潮 暗示着某些奇特活动的开始 Underwater a falling tide is the cue for some bizarre activity
这些动作缓慢的蛤蜊 用有力的脚 These slow moving clams use their muscular feet
将自己埋到沙里 to bury themselves under the sand
如果它们不找到掩护 lf they fail to get under cover,
潮水会使它们暴露在空气中 它们便会死去 the tide will leave them exposed to the air and they will perish
但只要在地底下 它们就能深深躲进沙里 But once underground they can wait deep down in the sand,
安全地留在海滩下 safe beneath the beach
而且时机恰好 And not a moment too soon
东南阿拉斯加的六月 短短4小时内 June in Southeast Alaska and in just four hours
一个广阔的沙滩 因退潮而显露 a vast sandy beach is exposed by the falling tide
熊群肚子饿了 在这时节里 The bears are hungry - at this time of year
它们很少在陆地上觅食 the pickings on land are few and far between
这里的食物 大概都早就被深埋在沙中 But any food here has long since buried itself deep under the sand
对一只饥饿的成年熊而言 并无所谓 To a hungry adult bear that is no barrier
它们能闻到沙中的蛤蜊 轻而易举地将它们挖出 - they smell the clams through the sand and simply dig them out
以体型硕大的动物来说 它们打开这些不幸的蚌类时 For such large animals, they show quite extraordinary dexterity
展现出惊人的灵敏度 at opening the unfortunate shellfish
小熊也想试试 但并不太成功 Cubs try their luck, too, none too successfully!
而成年熊群的蚌类大餐 却可持续整个退潮期 But for the adults the shellfish feast lasts as long as the tide remains out
这里是位于南非的桌山 Table Mountain in South Africa
每天退潮都会 在海滩某处留下漂浮物 Every day the retreating waves leave flotsam somewhere on the beach...
这只动物正从水流中 闻出腐烂鱼肉的味道 ...and this creature is scenting the currents for the odour of rotting fish
潮汐将气味带入碎浪区 The tide carries the scent far into the surf zone
闻到气味的海螺从沙中出现 Responding to the smell, snails emerge from the sand
这是与潮水的竞赛 海螺必须在潮水 This is a race against the tide - the snails need to find their meal
将食物带走前找到它们 before the tide leaves it beyond their reach
但海螺动作慢而退潮速度快 But snails are slow and the tides fall rapidly
然而这些并非一般的螺 These, however, are no ordinary snails
它们会冲浪 They can surf!
它们乘着海浪到达海滩 但潮水 They ride the waves up the beach but all too soon
即刻将鱼留在碎浪区外 the tide leaves the fish beyond the surf zone
没有海水 蜗牛就有闻不到气味的危险 Without the sea there's a danger that the snails will lose the scent,
但只要沙滩维持潮湿 它们就可以循着微弱的气味找到食物 but as long as the sand remains damp they can still follow a faint trail to the food
一旦发现它们便能大快朵颐 Once there they tuck in with macabre relish
等待终于还是值得 Good things come to those who wait!
不久后阳光的热度 Before long the heat of the sun forces them
迫使它们退回沙中 等待下一个潮汐的归来 to retreat into the sand to await the return of the next tide
英国的二月 February in Britain
这些鸟迫切地等待着退潮 The falling tide is eagerly awaited by these knot
退潮时无数的无脊椎动物 As the water retreats countless small invertebrates
在泥中找寻庇护 are seeking shelter under the mud
而这是情有可原的 And with good reason
涉水鸟是在泥中探索的专家 Waders are specialists at probing in the mud,
它们的各式嘴形 their wide variety of beak shapes designed
是为撷取不同 无脊椎动物而设计 for reaching different invertebrate dinners
也是解开潮汐区浅滩 所提供的保护的关键 Keys that unlock the safety of the tidal flats
但几小时内潮汐又会转向 But within a few hours the tide will turn again
很快地涉水鸟远离了这里 Soon the waders are out of their depth
泥中的生物也再次安全了 and the creatures of the mud are safe once more
前进的潮水能在水底 造成强烈的水流 Underwater incoming tides can create a strong current
而比目鱼是搭潮浪便车的专家 And flounder are experts at hitching a tidal lift
它们的形状近似风筝 如此设计很适合在潮水上滑行 They are shaped rather like a kite - a perfect design for gliding on the tide
在加拿大东岸的纽芬兰 ln Newfoundland on the East Coast of Canada,
众多的比目鱼 乘着潮浪流上浅滩 large numbers of flounder ride the currents up into the shallows
它们来此捕食水退后 出现的无脊椎动物 They have come to hunt invertebrates that will emerge now that the water is back
在浅滩上觅食的收获颇丰 The pickings in the shallows can be very good
这样的活动十分引人注意 The activity has not gone unnoticed
但鹗无法潜水太深 But Ospreys can't dive deeply
只要水深超过1公尺 比目鱼就很安全 As long as the water is more than a meter deep, the found then will be safe
离海岸太近是项危险的行为 Going too far inshore can be a risky business
这条鱼只要察觉到任何危险 就将自己完全埋在沙中 This fish buries itself completely in the sand at any sign of danger
但当潮水再度涌进 只要海岸空无一物 But when the tide floods in again, as long as the coast is clear
这些沙中的鱼就会再出现 - these sand lancet will re-emerge
在沙中等待6小时后 它们迫切渴望食物 After a wait of six hours under the sand, they are desperate for food and,
不同于比目鱼的是 它们向海上出发 unlike flounder, they head out to sea
它们在找寻浅而宽阔的海水 They are looking for shallow open water,
那里的潮流会聚集它们的食物 也就是浮游生物 where the tidal currents will concentrate their food - plankton
为数庞大的它们 游向最好的聚食场 ln their untold thousand they stream toward the best feeding grounds
它们可以轻而易举地 从水中找到浮游生物 Where they simply pick up tiny planktonic creatures from the water
但若它们为食物而离岸太远 But, if they swim too far off-shore in search of food,
它们就有遇上深海中 较大掠食者的危险 they risk running into large predators that live out in deeper water
属小型鲨的狗鲨 Dogfish - small sharks
柳叶鱼离开了它们的安全范围 The sand lancet have strayed out of their safe depth
转向潮浪的影响 对岩岸是完全不同的 The effect of the turning tide can be totally different on a rocky shore
在加拿大温哥华岛的海岸 太阳烘烤着暴露在外的岩石 Here on the coast of Vancouver lsland in Canada the sun bakes the exposed rock
退潮时重新躲回地底 是绝不可能的事 lt's virtually impossible to dig underground when the sea retreats,
于是这些贻贝及藤壶 完全地暴露在烈日下 so these mussels and barnacles are fully exposed to the heat of the sun
真的是在自己的壳里被烹煮 - literally cooking in their own shells
而海草则被晒至又干又脆 And the seaweed simply dry to a crisp
海水再回来 也许要几小时的等待 lt can be a wait of many hours before the water returns
每个月潮汐的大小 及强度不断改变 Throughout each month the size and strength of the tide changes
最强的潮汐 The biggest tides of all happen
发生在太阳和月亮 的地吸引力一起作用时 when the gravities of the sun and moon pull in unison
这发生在新月之后 That happens immediately after the new moon...
并再次在满月之后出现 ...and again after the full moon
它们称做朔望潮 These are called the spring tides
会使许多原本 被覆盖的海床露出 They reveal vast tracts of sea bed that would normally be covered
这是浣熊寻找 海鲜大餐的好时机 For these racoons it's a chance to look for a seafood feast
一个母亲带着幼熊去探险 A mother ventures forth with her kits
朔望潮时它们可以来到岸边 With the spring tide, they've come further down the beach
这是小潮期时无法做到的 than smaller tides would normally allow
靠着它们格外灵敏的爪子 Searching with their extraordinarily sensitive paws
它们找寻适合的食物 - they look for suitable prey
及低的潮水让它们 能找到特别的东西 With the extreme low tide they could find something special
还有什么能好过一只红岩蟹 And what could be better than a red rock crab
这是如果可以不被夹痛的话 That is, if it weren't for the risk of a painful pinch
要抓到一只大螃蟹 还是要靠经验 With large crabs there's no substitute for experience
这个母亲专业地出击 - the mother makes an expert's catch
但小浣熊也学的很快 But the kits learn fast!
而学不快的就只好试着乞讨 And for those that don't - begging is always worth a try!
很快的浪潮会淹没 浣熊们的餐桌 All too soon the returning tide will cover the racoon's table
对无脊椎动物来说这是种解脱 For all the invertebrates it is a welcome relief,
但在不好的天气里 它们会面对最糟的海浪 but in rough weather they are exposed to the worst of the waves
即使没有海浪 前进的潮水 Even when there are no waves - the incoming tide
仍会在水下 形成相当大的力量 can create considerable forces underwater
温哥华东岸 The gaps between these small islands on
这些小岛间的间距 形成潮流的航道 the East coast of Vancouver lsland channel the tidal flow
当潮水持续上升 水流逐渐加快 As the tide keeps rising, gradually the water flows
而这些30公尺长的巨藻 faster and soon these giant thirty metre
就会顺势弯曲 long bull kelp plants bend to the current
它们的柔软度足够 能不受损害地适应环境 They are sufficiently flexible to cope without too much damage,
但有些地区的水流特别强烈 but there are some spots where the currents are especially powerful
这里是那克瓦多湍流 This is the Nakwakto Rapids
当潮水转向时 从近700里外峡湾而来的水 At the turn of the tide, water from almost seven hundred miles
将必须经过一条 of coastal fjords will have to empty through a gap
窄过半里的缺口 of less than half a mile wide
几分钟内水流已开始加速 Within a few minutes the current is already picking up speed,
直到水以 每小时17里的速度前进 until water roars by at over seventeen miles per hour
潮流的力量并不只会带来破坏 Tidal currents are not always a damaging force
例如在纽西兰的普尔奈群岛 - here in the Poor Knight lslands of New Zealand,
微弱的潮流流过海石拱 weak tides run through rock arches,
成了魟鱼最佳的栖息地 making an ideal resting place for stingrays
每年三月这些魟鱼大量聚集 These rays congregate here in huge numbers every March
它们是来交配的 - they've come to breed
这些海石拱将潮流汇集 让这些魟鱼 The arches funnel the current, which the rays can ride
可以轻易乘海流而行 保存一些体力 with a minimum of effort, so saving energy
在附近的开阔水域 一群散点光鳃雀鲷 Nearby, out in open water, a school of two spotted desmoiselle fish
正在吃浮游生物 潮流流向 are feeding on plankton and the current
正好将食物扫向它们 is perfect for sweeping their food past them
当潮流转弱时 Once the current starts to weaken,
食物就会减少 也不值得冒险到 there is insufficient food to warrant the risks of swimming
开阔水域觅食 about out here in the open
所以全体雀鲷掉头另觅住所 So the desmoiselles head off to find shelter en-masse
安全还是最重要的 Safety is in numbers
越来越多的雀鲷 朝普尔奈群岛上 More and more desmoiselles pour towards the cave entrances
蜿蜒的洞穴的入口处游来 that riddle the Poor Knight's islands
在这里较不会暴露在 Safe at last - inside the cave
掠食者的攻击之下 它们终于安全了 they are far less exposed to attack from predators
数千只雀鲷及蓝帽 在此等待潮流再度到来 Thousands of desmoiselles and blue mao mao wait for the return of the current,
它们才能游到开阔水域觅食 when once again they will head out into the open to feed
月球引力在地球赤道附近较弱 The moon's gravitational pull is weaker nearer to the earth's equator,
所以越接近赤道的地方 潮流也就越弱 so the more equatorial the location, the smaller the tides
在加勒比海域 潮汐只有些微的涨退 And out here in the Caribbean Sea the tidal movements are slight
即使如此潮流的力量还是足以将 会活动的浮游生物推向它们的旅程 Even so, they are sufficient to push free swimming plankton in their path
这些是顶针水母 These are thimble jellyfish
它们朝阳光游去 而潮汐活动所形成的隐形边界 They swim towards the sunlight and invisible boundaries
则有助于它们的聚集 直到它们汇整而成巨大的一群 formed by the tidal motion help to herd them together,
它们很会利用热带的阳光 until they gather in immense swarms
身上的棕色来自 They put the tropical sunshine to good use
居住在体内的藻类 - their brown colour comes from algae that
藻类会利用日光行光合作用 以制造能源 live inside the jellyfish's bodies and photosynthesise energy from the sun
在宽阔的远洋中 它们算是安全的 ln open water they are fairly safe,
但是潮流正将这一群水母 慢慢带往巴哈马水域 but the tide is sweeping the whole swarm gently towards the Bahamas,
在那里有许多张嘴 垂涎着它们 where hungry mouths are waiting
虽然海平面高度改变不大 Although the sea level does not change much
潮流还是将容积庞大的海水 - the tides are still pushing an enormous volume of water
从汪洋中 推进岛上礁岩的细缝间 from the ocean through the small gaps between the island cays
在海面下 这些潮流奔流过软珊瑚 Underwater the tidal currents race past soft corals
层叠翻过沙岸 And on over the sandy banks themselves...
这是一大片的珊瑚沙滩 只有在涨潮时会被淹没 lt is an immense area of coral sand that is only just submerged at high tide
这波迎面而来的浪潮 将会带来新的浮游生物 This incoming tide is bringing in a fresh supply of oceanic plankton
而蔷薇虹彩鲷也聚在 捕食微生物大餐的最佳位置 and razorfish gather at the best spots to catch the pick of the microscopic feast
虽然食物足够这些小鱼饱餐 Although there is plenty here for these small fish to eat,
但是群聚在此却也让 天敌更容易找上它们 gathering in one place makes it easy for their predators to find them
猫鲨算不上什么威胁 A nurse shark is little threat
但是这个声音 传来的警讯可就不同了 But this sound heralds a quite different danger
是一只瓶鼻海豚 A bottlenose dolphin
他正利用声纳系统 找出沙里的蔷薇虹彩鲷 lt's using its sonar to locate razor fish beneath the sand
找到合适的目标后 就挖出它的猎物 Once it finds a suitable target it simply digs out its prey
埋在沙中的鱼毫无招架之力 The buried fish have no defence against this attack
只能等待 并希望自己不要被找到 They will simply have to wait and hope they aren't found out
这只海豚好像有了虹彩鲷瘾 那是因为她怀孕了 This dolphin appears to have a razor fish craving - well, she is pregnant
最后终于成功了 Success, at last
这波逼近中的浪扫向美国 The incoming tide sweeps on towards America,
淹过这片广大的水草 flooding across vast flat plains of seagrass
这里的水极浅 所以在退潮时 They are so shallow that, at low tide,
大型鱼都被迫要避到深水道中 all large fish are forced to retreat into deep water channels
就像这只猫鲨还有魟鱼 Like these nurse sharks... and these stingrays
两只肉食鱼类 都会猎食浅滩上的甲壳类 Both predators hunt crustaceans on the seagrass beds,
在水位涨到足以 让它们前来觅食前 but until the flooding tide brings enough water for them to swim in,
它们也只能等待 they will have to wait
所以这只郁金香螺 可以趁此时安全地 So for now this tulip snail it appears safe
在浅水中来回寻找食物 to patrol the shallows in search of a meal
但它确实是安全无虞的吗？ But is it?
这是一只体型较大的海螺 This l s a rather bigger kind of snail
一只重达五公斤的旋螺 At five kilogrammes in weight, the giant horse conch
根本不怕用任何鲨鱼 而且它嗜食郁金香螺 has little to fear from any shark... and it has a taste for tulip snail
察觉到危险的逼近 海螺逃了 Sensing the approaching danger - the snail flees
但是以海螺世界的速度来说 旋螺像是一台法拉利 But in a world of snail paces - the conch is something of a Ferrari
需要使出非常手段了 lt calls for desperate measures
被自己最后一次的遁逃 弄得疲累不堪的郁金香螺 Exhausted by the effort of its last ditch attempt,
眼看就要被猎走了 the tulip snail is slowly gunned down
大型的猎食者要等潮水 再涨一个小时才能出动 The tide still has to rise for another hour before the big predators can feed
但是在浅滩上垂死海螺的味道四溢 也是这些寄居蟹偏爱的味道 But out on the flats the scent of dying snail wafts away on the tide
对这些螃蟹来说 找到足够的保护可以躲过 lt's a scent that these hermit crabs are particularly partial to
一旁等待的鲨鱼及魟的利齿 lt's vital that the crabs have the best possible protection
是非常重要的大事 from the heavy teeth of the waiting sharks and rays
所以它们需要一个 大小完全合适的壳 For that they need the shell with a perfect fit
今天有新居待价而沽 Today there is new real estate on offer
而房屋市场的竞争也剧烈异常 - and competition in this housing market is fierce
当被吃掉的海螺的壳 就要被弃置时 The action becomes even more desperate
它们的动作变得更拼命 when the shell of the devoured snail is ready for release
这只寄生蟹不能再等了 This crab simply can't wait any longer
但是它所冒的险也是奇大 But it's a decidedly risky acquisition
冒险的代价甚是美好 新壳比老家轻 The risk paid off handsomely - the new shell is both lighter
也坚硬许多 时间算得刚好 and stronger than the old home and it's not a moment too soon
因为此时潮水来得极猛 已经淹过这片平原 because the tide is flowing in strongly, flooding the plains
肉食动物终于可以开始掠食 At last, the predators are free to start their foraging
魟鱼和鲨鱼 都有高度演化的电流感应器 Both the stingrays and sharks have a highly developed electrical sense
它们用它来找寻 埋在沙中的无脊椎动物 which they use to search for buried invertebrates
就连沙中 最细微的动作也能察觉 - they can sense minute movements beneath the sand
这只魟鱼有了可靠的讯息 挖出它的猎物 Finding a promising signal, this ray digs out its meal,
一只毫无保护的 寄居蟹只有死路一条 an unprotected hermit crab would have no chance
数小时内，又是退潮 Within a few hours the tide ebbs out once more,
所有的掠食者又得被迫离开 and all the predators are forced to leave
它们须等到下一次涨潮 They will have to wait until the next high tide
才能再度出外猎食 before making another feeding foray
一年中有个时节称作春分 At certain times of the year called the equinox,
此时的朔望潮水特别猛 卷起的高度比平时要高 spring tides are exceptionally large and rise even higher than normal
猎食动物也可以 游至水滩中最浅的水域 Now predators can reach the very shallowest fringes of the seagrass flats
这些长2公尺的大海鲢 正朝更里岸游去 These two metre long tarpon are heading further inshore still
它们的目标是红树林 They are heading for the mangroves
这些水中森林广布沿岸浅滩 These flooded forests cover huge areas of the coastal shallows
这些惊人的水笔仔 Extraordinarily, the roots of the mangrove trees
根部可以在咸水中生存 也成了小鱼最佳的育婴房 can live in salt water and they make a perfect nursery for small fish
银鱼与笛鲷在这 盘根错节的迷宫中找到庇护 Silversides and snapper find sanctuary in the maze of roots
大型掠食鱼进不了这里 - big predators seldom find a way in here
又是退潮时候 And now the tide is falling once more
水中本就极少的含氧量 又开始下降 The water starts losing what little oxygen it contained
水又开始浑浊 and quickly becomes stagnant
大部分的掠食者离弃红树林 Most predators have abandoned the mangroves,
但是这些鲢鱼 却因退潮身陷此地 but these tarpon are still here trapped by the falling tide
水中氧气快速减少 The dissolved oxygen is fast running out,
但是它们有一个重要求生技巧 but they have a vital survival technique...
它们可以在这里呼吸 ...they can breathe air
体内再度充满氧气的鲢鱼 可以轻易 Pumped up with fresh oxygen they can easily out
战胜闲散的银鱼 manoeuvre the dozy silversides
潮汐再度变换 The tide has turned again
这可不是普通的浪 And this is no ordinary tide
春分时节，潮浪会快速窜起 Since it is the equinox - the tide is rising fast
但是海中央又有飓风正要来临 将潮浪卷起到更高的高度 but now out to sea a hurricane is on its way, forcing the tide yet higher
暴风雨的侵袭 让沿岸许多地方都淹水了 The passing storm leaves large areas of the coast flooded by the sea...
地势较低的岛屿 像是巴哈马群岛 ...and the low lying islands like the Bahamas
更容易因为暴风雨侵袭而淹水 are even more prone to storm flooding
太阳的力量 在这里是很强大的 The sun's power here is immense
当潮水退去，剩余的水蒸发 As the tide recedes and the remaining flood water evaporates
惊人的改变发生了 - a remarkable transformation takes place...
泥巴上多了一层 神奇的盐世界 The mud is coated with a magical world of salt
剩余的水中，盐的浓度极高 没有多少生物可以在此生存 Any remaining water is extremely salty - very few creatures can survive here...
除了这些丰年虾 ...except these brine shrimp
还有水边的咸水苍蝇以外 And on the water's edge, brine flies
它们都是一种奇妙的动物 最爱吃的食物 Both are the favourite food of an extraordinary animal
它就是加勒比海火鹤 The Caribbean Flamingo
特别的是，它们会特意寻找 这些咸水区域 Remarkably, they actually seek out such briny places
这里是它们觅食的最佳场所 - they are the best spots for them to find their food
这里也提供了火鹤 抚育幼子时所需的保护 And they also provide the protection the flamingos need to raise their young
这类的筑巢地点 被具侵蚀性的咸水包围着 Nesting sites like this are surrounded by corrosive brine
对任何想以火鹤幼子为食的 掠食者来说，这里是铜墙铁壁 lt's a formidable barrier to any predators seeking to dine on flamingo chicks
火鹤在巢的四周 小心高筑泥围墙 The Flamingo takes the precaution of building next
以防水患再起 Just in case of further flatting
奇异的是 火鹤的食物及栖息地 Strangely, it's actually the power of the storm tides
都是暴风雨潮水的 that gives the flamingos both their food
力量所带来的 and a perfect habitat in which to breed
海洋中许多动物的繁殖 The breeding of many animals in the ocean
都与潮汐循环有着密切关系 is closely co-ordinated with the tidal cycles
11月间的弦月 是低潮的时期 A half moon in November. lt is the time for small tides.
这里是太平洋上的圣诞岛 Christmas lsland in the Pacific
有奇事即将发生 Strange happenings are afoot
今晚是一年中少有的夜晚 lt is one of only a few nights each year
母圣诞岛蟹会在今晚 冒着危险走向大海 when female Christmas lsland crabs risk heading down towards the sea
成千上万的蟹群 分布在岛周围 Around the island they number in tens of thousands
每只身上都背有数百颗卵 and all of them are laden with hundreds of eggs
它们要把卵甩到水中 卵才能孵化成幼蟹 They have to shed them into the ocean if the eggs are to develop into baby crabs
因为它们是陆生蟹，所以不会游泳 也无法在水中呼吸 But these are land crabs and they can neither swim nor breathe underwater
它们有淹死的危险 There is a great risk of drowning,
所以选在潮汐最弱时行动 which is why they pick the smallest tides of the month
好将危险降到最低 - to minimise the danger
蟹卵会在离岸较远处生长 The eggs will develop far offshore and in exactly
一个月后 就会有一大群小蟹回游 one month's time a great swarm of baby crabs will return,
也是选在潮汐最佳的时机 again choosing the perfect tide
无论是日循环或月循环 Whether it's the daily or monthly cycle,
潮汐是大海的节奏 是它的节拍器 tides are the rhythm of the ocean - its pulsing clock
每一个潮流都为地球上 某处的海洋生物带来生机 For every tide brings opportunity to marine life somewhere in the world
此时朔望潮将浅摊淹没 掠食者来回巡行 Now a spring tide is flooding the shallows and hunters are on the prowl
一小群瓶鼻海豚 正朝海岸上前进 A small group of bottlenose dolphin are working their way
准备进行一项 十分特别的猎食行动 inshore to start a quite extraordinary hunting campaign
在一次完美的传接后 海豚马上准备重新来过 After one successful pass the dolphin move off to start again
一只海豚离开团体 一圈圈快速游泳来卷起泥巴 One animal peels off from the group and swims rapidly in a circle,
将乌鱼赶往其他等待中的海豚 stirring up the mud and driving the mullet towards the other waiting dolphins
真是惊人的团队合作 而它的效率也一样惊人 lt's a remarkable team effort and it is extremely effective
海豚会在潮水深度仍在 它们活动范围的情况下 The dolphin will feed like this for as long as the tide grants
继续以这种方式在浅滩捕食 them access to the shallows
最后，海豚会因退潮 而被迫离开 Eventually the falling tide will force the dolphin to leave the flats
这片浅滩及乌鱼又是安全的了 至少在下次涨潮前是如此 and the mullet will be safe once more - until the next high tide
在大海里，每回潮汐的来去 Because in the ocean every turn of the tide spells
都掌握着生与死的分别 the difference between life and death, somewhere