牡蠣發揮凈水功能

The waters around New York City used to be home to millions of oysters. Rich and poor 2)dined on them and they were one of the city’s biggest exports. But the water became more and more polluted and the oysters 3)died off. And with them went the 4)bivalve’s incredible ability to help clean the water.

Dr. Ray Grizzle: When they feed， the upper 5)valve raises up， and they have 6)ciliated 7)gills， these sheets of 8)tissue， and pump water through them. And as the water goes through them， there’s a gas exchange， gills， same as in fish， but in the case of the oyster， the…the 9)particles that are in the water are filtered out as well.

These waters， 10)in the shadow of New York’s LaGuardia Airport， are anything but clean. But slowly， Dr. Ray Grizzle and his team are trying to help oysters take root again. Not too long ago you wouldn’t have found any oysters in this water， but things are changing.

Dr. Grizzle: So we’ve got a…we’ve got an oyster that’s fully reproducing female， probably， two years headin’ into its 3rd year， and…and looks good and healthy. Good girl. This is the really good news.

Kate Orff is a landscape architect， and she’s hoping to put bivalves’ unique ability to clean to good use. Orff sees a future where oysters and other bivalves can help reshape the urban landscape， even help the Gowanas Canal， one of the nation’s most polluted waterways， become an attraction.

Kate Orff: Oyster-tecture was 11)conceptualized as setting into motion a system where baby oysters could be seeded in the Gowanas and then flow out and build up and develop on the Bay Ridge Flats， which we’re calling the， sort of， Palisades Bay Reef. So you have the cycle set in motion of， sort of， baby oysters， reef building， cleaner water.

Orff and Grizzle both know that oysters are not the sole solution. The city needs to want the waterways to be clean and take the necessary steps in that direction. While oysters can’t do it on their own， Grizzle believes they can help.

Dr. Grizzle: The thing about oyster restoration that’s different than perhaps just about any other efforts that I know of， it has multiple benefits; the 12)habitat quality that improves habitat for fish and various other species， and it also provides water filtration that will affect water quality.

These oysters won’t be going for three bucks a pop in the city. They are not for consumption. But Grizzle hopes the more of them that grow， the cleaner the water will get， and maybe in the future oysters from these waters will be clean enough to 13)shuck.

紐約周邊的水域曾經棲息著幾百萬只牡蠣，無論貧富，這個城市的居民都會將它們擺上餐桌；它們也曾是這個城市最主要的出口物。后來，這里的水污染越來越嚴重，牡蠣也逐漸滅絕。隨之一同消失的，還有這種雙殼貝類驚人的凈水能力。

雷·格力茲博士：牡蠣進食時，上殼抬起，它們有帶纖毛的腮，也就是這薄薄的幾層組織，把水吸入腮中。水進入腮后，會有一次氣體交換，牡蠣的腮和魚類相似，但牡蠣會過濾水中的微粒。

這片位于紐約拉瓜迪亞機場附近的水域污濁不清。但逐漸地，雷·格力茲博士和他的團隊嘗試讓牡蠣在這里重新扎根。不久以前，你很難在這里發現牡蠣的蹤影，但現在情況開始發生改變了。

格力茲博士：我們這里有只……完全具備生殖能力的雌牡蠣，大約兩歲多，快三歲了，看上去非常健康。好樣的。這真是個好消息。

凱特·奧爾夫是名園林技師，她希望能很好地利用雙殼貝獨一無二的凈水能力。奧爾夫預計在不久的將來，牡蠣和其他雙殼貝可以重塑城市景觀，甚至可以把戈萬納斯運河——全美污染最嚴重的河道之一——改造成觀光景點。

凱特·奧爾夫：牡蠣結構學這個概念已成形，并且這個體系已經開始運作：在戈萬納斯運河育苗，再將它們放養出去，在灣嶺淺灘形成我們稱作帕利塞茲灣礁的地方。這個循環不斷重復：育苗、建礁、凈水。

奧爾夫和格力茲都知道，牡蠣并不是凈水的惟一救星。這個城市需要決意凈化水道，并向這個方向努力，采取必要措施。