大自然的“过滤器”正在消亡，没有人知道原因

大自然的“过滤器”正在消亡，没有人知道原因

The shells lie open at the bottom of the river, shimmering in the refracted sunlight. Their insides, pearl white and picked clean of flesh, flicker against the dark riverbed like a beacon, alerting the world above to a problem below.

贝壳在河底张开，在折射的阳光下闪闪发光。它们的身体，洁白如珠，剔得干干净净，像灯塔一样在黑暗的河床上闪烁，提醒着上面的世界注意下面的问题。

"That's what we look for in die-offs," says biologist Jordan Richard, standing knee-deep in the slow-flowing waters of the Clinch River in southwest Virginia. He points at a faint shape submerged about 10 feet upstream. "I can tell from here that's a shell, it's dead and it died recently. The algae development is really light."

生物学家乔丹·理查德站在弗吉尼亚州西南部克林奇河齐膝深的缓流水域中说:“这就是我们在动物死亡中寻找的东西。”他指着上游大约10英尺处一个模糊的物体。“我从这里就能看出那是只雉鸡壳，它死了，最近才死的。藻类的生长真的很缓慢。”

In recent years, though, biologists and fishermen noticed something was wrong. On sections of the Clinch and other waterways in the Pacific Northwest and Midwest, dead mussels were turning up on shores and could be seen glinting from the river bottom.

然而，近年来，生物学家和渔民发现了一些问题。在太平洋西北部和中西部的克林奇河和其他水道的一些河段，可以看到死贻贝在河底闪闪发光。

On the Clinch River alone, hundreds of thousands are believed to have perished, a mass mortality event that has baffled scientists and alarmed ecologists.

据信，仅在克林奇河就有数十万贝壳死亡。这一大规模死亡事件令科学家困惑，也令生态学家感到恐慌。

Freshwater mussels, like pollinators and trees, are critical to their larger ecosystems and the world around them. They create habitat for other species, like freshwater coral reefs, and help maintain the structure and rigidity of the waterways they call home. They scoop up algae and nutrients, processing and concentrating them for others to eat.

淡水贻贝，像传粉者和树木一样，对它们更大的生态系统和周围的世界至关重要。它们为淡水珊瑚礁等其他物种创造了栖息地，并帮助维持它们称之为家的水道的结构和硬度。它们把海藻和营养物质捞起来，加工并浓缩起来供其他动物食用。

But perhaps most importantly, these soft-bodied invertebrates improve the water quality around them (check out this video.) They filter out sediment and agricultural runoff, limiting the size and impacts of dead zones. They reduce fecal bacteria from water, lowering the risk of E. coli.

但也许最重要的是，这些软体无脊椎动物改善了它们周围的水质。它们过滤掉了沉积物和农业排水，限制了死亡区的面积和影响。它们减少了水中的粪便细菌，降低了大肠杆菌的风险。

They sequester carbon, phosphorous and heavy metals. There's even evidence they can remove man-made contaminantsfrom water such as pharmaceuticals, flame retardants and personal care products.

它们能隔绝碳、磷和重金属。甚至有证据表明，它们可以清除水中的人造污染物，如药品、阻燃剂和个人护理产品。

A single freshwater mussel can filter more than 15 gallons of water in a day.

一个淡水贻贝一天可以过滤超过15加仑的水。

They're like nature's "filter," says Emilie Blevins, a conservation biologist with the Xerces Society for Invertebrate Conservation, an Oregon-based nonprofit that's monitoring and studying the recent die-offs.

它们就像大自然的“过滤器”，埃米利·布莱文斯是Xerces无脊椎动物保护协会的一名保护生物学家，Xerces协会位于俄勒冈州，是一家监测和研究最近物种灭绝的非盈利组织。

"The loss is really huge and it's happening really quickly," Blevins says. "It's a major concern for the future and for the future of our fresh water."

“损失是巨大的，而且发生得非常快，”布莱文斯说。“这是对未来和我们的淡水的未来的主要担忧。”

Freshwater mussels are one of most imperiled species on the planet. Nearly three-quarters of North America's roughly 300 native mussel species are endangered, at risk, or of concern. Dozens are already extinct. Humans are the primary cause.

淡水贻贝是地球上最濒危的物种之一。北美约300种本地贻贝中，有近四分之三濒临灭绝或受到威胁。数十种已经灭绝。人类是主要原因。

For decades, freshwater mussels were overharvested for their shells. Before the era of plastic, they were collected and cultivated by the millions to satisfy a commercial demand.

几十年来，淡水贻贝因其外壳而被过度捕捞。在塑料时代之前，它们被数以百万计的人收集和种植，以满足商业需求。

A recent report by the United Nations found that human practices have put roughly 1 million species at risk of extinction, many within decades.

联合国最近的一份报告发现，人类的行为已经让大约100万个物种面临灭绝的危险，其中许多物种会在几十年内灭绝。

"The essential, interconnected web of life on Earth is getting smaller and increasingly frayed," wrote Josef Settele, a German biologist and co-chair of the report. "This loss is a direct result of human activity and constitutes a direct threat to human well-being in all regions of the world."

“地球上必不可少的、相互联系的生命网络正在变得越来越小，而且越来越脆弱，”该报告的联合主席、德国生物学家约瑟夫·塞特尔写道。“这种损失是人类活动的直接结果，并对世界所有区域的人类福祉构成直接威胁。”

Nature is so complex. Biology is so complex. We do not understand how important some things are until they're gone.

大自然是如此复杂。生物学是如此复杂。有些东西只有消失了，我们才知道它有多重要。