海灘還是那個海灘 但沙子都到哪兒去了

BERKELEY, Calif. — TO those of us who visit beaches only in summer, they seem as permanent a part of our natural heritage as the Rocky Mountains and the Great Lakes. But shore dwellers know differently. Beaches are the most transitory of landscapes, and sand beaches the most vulnerable of all. During big storms, especially in winter, they can simply vanish, only to magically reappear in time for the summer season.

加利福尼亞伯克利——對於只在夏天去海邊遊玩的人來說，海灘彷彿是一種永久的自然遺產，就像落基山脈和五大湖一樣。然而，住在海邊的人知道，事實並非如此。海灘是最容易轉瞬即逝的地貌，而沙灘又是其中最爲脆弱的一種。遇到大風暴，尤其是在冬天，它們會消失，待到來年夏季將至的時候又會神奇地及時重現。

It could once be said that “a beach is a place where sand stops to rest for a moment before resuming its journey to somewhere else,” as the naturalist D. W. Bennett wrote in the book “Living With the New Jersey Shore.” Sand moved along the shore and from beach to sea bottom and back again, forming shorelines and barrier islands that until recently were able to repair themselves on a regular basis, producing the illusion of permanence.

博物學家D·W·本內特(D. W. Bennett)在《與新澤西海灘共度時光》(Living With the New Jersey Shore)一書中寫道，“海灘是沙子在繼續前往別處之前停留片刻的地方。”曾幾何時，的確可以這麼說。沙子沿着水岸運動，從灘塗到海底再到灘塗，塑造了海岸線和堰洲島。直到不久前，這些地貌還能經常自我修復，製造出一種永恆的假象。

Today, however, 75 to 90 percent of the world’s natural sand beaches are disappearing, due partly to rising sea levels and increased storm action, but also to massive erosion caused by the human development of shores. Many low-lying barrier islands are already submerged.

然而今天，世界上75%到90%的自然沙灘正在消失。部分原因在於海平面上升和風暴活動增加，但更重要的是，人類對海灘的開發造成了大規模的侵蝕。許多地勢較低的堰洲島已經被海水淹沒。

Yet the extent of this global crisis is obscured because so-called beach nourishment projects attempt to hold sand in place and repair the damage by the time summer people return, creating the illusion of an eternal shore.

可是，由於所謂的“人工育灘”計劃，這一全球性危機的嚴重程度遭到了忽視。這些工程努力在夏季遊客到來之前將沙子留在原處並修復損失，製造出一種海灘永在的幻象。

Before next summer, endless lines of dump trucks will have filled in bare spots and restored dunes. Virginia Beach alone has been restored more than 50 times. In recent decades, East Coast barrier islands have used 23 million loads of sand, much of it mined inland and the rest dredged from coastal waters — a practice that disturbs the sea bottom, creating turbidity that kills coral beds and damages spawning grounds, which hurts inshore fisheries.

下個夏天到來之前，看不到盡頭的自卸車隊會運來材料填補裸露的地表並修復沙丘。光是弗吉尼亞海灘，就被恢復了逾50次。近幾十年裏，美國東海岸的堰洲島用掉了2300萬車的沙子，其中許多采自陸地，其餘則從沿海水域挖掘。挖沙的做法會干擾海牀，產生不利於珊瑚礁生存並會破壞生物繁殖地的渾濁海水，從而損害近海漁業。

The sand and gravel business is now growing faster than the economy as a whole. In the United States, the market for mined sand has become a billion-dollar annual business, growing at 10 percent a year since 2008. Interior mining operations use huge machines working in open pits to dig down under the earth’s surface to get sand left behind by ancient glaciers. But as demand has risen — and the damming of rivers has held back the flow of sand from mountainous interiors — natural sources of sand have been shrinking.

砂石行業的增長如今比整體經濟更爲迅猛。在美國，開採出來的沙子已形成了每年上十億美元的市場規模，2008年以來的年增長率爲10%。內陸採砂採用大型機械露天作業，挖開地表，以便開採出古老冰川留下的砂石。不過，隨着需求的增加，以及在水上修建大壩的行爲阻止了泥沙從多山的內陸地區向外的遷移，砂石自然資源一直在縮減。

One might think that desert sand would be a ready substitute, but its grains are finer and smoother; they don’t adhere to rougher sand grains, and tend to blow away. As a result, the desert state of Dubai brings sand for its beaches all the way from Australia.

人們或許會認爲，來自沙漠的沙子應當是現成的替代品。但實際上，這種沙粒更細、更光滑，不能與較爲粗糙的沙粒黏合，而且容易被吹走。因此，沙漠之國迪拜需要爲了本地的海灘萬里迢迢從澳大利亞進口沙子。

And now there is a global beach-quality sand shortage, caused by the industries that have come to rely on it. Sand is vital to the manufacturing of abrasives, glass, plastics, microchips and even toothpaste, and, most recently, to the process of hydraulic fracturing. The quality of silicate sand found in the northern Midwest has produced what is being called a “sand rush” there, more than doubling regional sand pit mining since 2009.

現在出現了海灘用沙的全球性短缺，而導致這種短缺的是越來越依賴砂石的各大行業。沙子是生產磨料、玻璃、塑料、微芯片乃至牙膏的關鍵用料，最近還成爲水力壓裂工藝中不可或缺的一環。美國中西部北面發現的硅砂在當地掀起了一股“淘沙熱”，使得該地區的沙坑開採活動自2009年以來翻番有餘。

But the greatest industrial consumer of all is the concrete industry. Sand from Port Washington on Long Island — 140 million cubic yards of it — built the tunnels and sidewalks of Manhattan from the 1880s onward. Concrete still takes 80 percent of all that mining can deliver. Apart from water and air, sand is the natural element most in demand around the world, a situation that puts the preservation of beaches and their flora and fauna in great danger. Today, a branch of Cemex, one of the world’s largest cement suppliers, is still busy on the shores of Monterey Bay in California, where its operations endanger several protected species.

不過，所有工業生產中耗沙量最大的是混凝土行業。自19世紀80年代以來，來自長島華盛頓港的砂石——1.1億立方米——一直在爲曼哈頓的通道和路面建設貢獻力量。採砂業的80%產量目前依然流向了混凝土行業。除了水和空氣，沙子是全球範圍內需求量最大的自然產物。這一現狀威脅到了對海灘和生長在其中的動植物進行保護的工作。就在當下，世界最大的水泥供應商之一西麥斯集團(Cemex)旗下的一家分公司，仍然在加州蒙特雷灣的海灘積極採砂，危及到了數種保護物種。

The huge sand mining operations emerging worldwide, many of them illegal, are happening out of sight and out of mind, as far as the developed world is concerned. But in India, where the government has stepped in to limit sand mining along its shores, illegal mining operations by what is now referred to as the “sand mafia” defy these regulations. In Sierra Leone, poor villagers are encouraged to sell off their sand to illegal operations, ruining their own shores for fishing. Some Indonesian sand islands have been devastated by sand mining.

全球範圍內興起的大型採砂活動中，許多都屬非法行爲，但它們並未進入發達國家的視野，也未被放在心上。不過在印度，政府已出手限制在海岸附近採砂，但那些已被人稱爲“採砂黑手黨”的非法開採集團對這些監管規定視而不見。在塞拉利昂，貧困村民受到鼓勵，要將沙子賣給非法企業，從而徹底破壞了當地的近海捕魚環境。一些印度尼西亞的沙島因採砂而遭遇重創。

It is time for us to understand where sand comes from and where it is going. Sand was once locked up in mountains and it took eons of erosion before it was released into rivers and made its way to the sea. As Rachel Carson wrote in 1958, “in every curving beach, in every grain of sand, there is a story of the earth.” Now those grains are sequestered yet again — often in the very concrete sea walls that contribute to beach erosion.

是時候讓我們瞭解沙子的來源和去向了。它曾被困在山上的岩石裏，經過億萬年的侵蝕才得以進入山川河流，然後來到海里。正如蕾切爾·卡森(Rachel Carson)1958年寫下的那樣，“在每個蜿蜒的海灘，在每顆沙粒之中，都藏有大地的故事。”現在，這些沙礫卻再次受困——往往就在那些助推海灘侵蝕的混凝土防波堤裏。

We need to stop taking sand for granted and think of it as an endangered natural resource. Glass and concrete can be recycled back into sand, but there will never be enough to meet the demand of every resort. So we need better conservation plans for shore and coastal areas. Beach replenishment — the mining and trucking and dredging of sand to meet tourist expectations — must be evaluated on a case-by-case basis, with environmental considerations taking top priority. Only this will ensure that the story of the earth will still have subsequent chapters told in grains of sand.

我們不能再認爲沙子取之不盡用之不竭，而是要把它當成一種稀缺的自然資源。玻璃和混凝土可以通過回收最終變回沙子，但這永遠不夠滿足度假村的需求。因此，我們需要更好的辦法來保護海灘和沿海地區。“海灘修復”項目——用採砂、運沙和挖沙的手法來滿足遊客的期待——必須一個一個通過評審，並讓環境方面的因素成爲優先考慮的對象。只有這樣，才能確保大地的故事還可以在沙粒中寫就後續的篇章。