對蜜蜂有害的東西也可能對海洋生物有害

對蜜蜂有害的東西也可能對海洋生物有害

Over the past two decades, farmers hoping to ward off pests have increasingly turned to planting seeds that come straight from the supplier pre-coated in neonicotinoids, a controversial class of insecticide chemically related to nicotine. With the insecticide built into the seeds, farmers no longer have to spray their fields with toxic chemicals, theoretically reducing the risk to non-target species.

在過去的20年里，希望避開害蟲的農(nóng)民越來越多地開始種植直接來自供應商的種子，這些種子被預先涂上新煙堿類殺蟲劑的涂層。新煙堿類殺蟲劑是一種有爭議的殺蟲劑，其化學成分與尼古丁有關(guān)。在種子中植入殺蟲劑后，農(nóng)民不再需要向田地里噴灑有毒化學物質(zhì)，這在理論上降低了對非目標物種的風險。

But as it turns out, neonics, as they’re also known, do impact other species—most famously honeybees, the steep decline of which has been linked to the insecticides. That discovery led the European Union to ban neonics in 2018. However, they remain widely used in the United States, as well as in Canada, though with some restrictions. Now, Haley Davis, an undergraduate student studying toxicology in marine ecosystems at Hollings Marine Laboratory in South Carolina, and her colleagues are raising yet another reason to be concerned about the insecticides. Neonics dissolve easily in water, they say, and could be harming marine life.

但事實證明，新煙堿確實影響了其他物種——最著名的是蜜蜂，殺蟲劑導致了蜜蜂數(shù)量的急劇下降。這一發(fā)現(xiàn)導致歐盟在2018年禁止了新煙堿。然而，盡管有一些限制，它們?nèi)匀辉诿绹图幽么蟊粡V泛使用。現(xiàn)在，南卡羅來納州霍林斯海洋實驗室(Hollings marine Laboratory)研究海洋生態(tài)系統(tǒng)毒理學的本科生海莉·戴維斯(Haley Davis)和她的同事提出了另一個關(guān)注殺蟲劑的理由。新煙堿很容易溶解在水中，他們說，可能會傷害海洋生物。

Davis and her fellow researchers presented the results of their examination into the effects of imidacloprid, a common neonicotinoid, on coral and reef-dwelling species that are vulnerable to runoff from coastal agriculture at a scientific meeting in February.

戴維斯和她的同事在2月份的一次科學會議上展示了他們的研究結(jié)果，他們研究了吡蟲啉(一種常見的新煙堿類殺蟲劑)對珊瑚和居住在礁石上的物種的影響，這些物種很容易受到沿海農(nóng)業(yè)徑流的影響。

They found that coral exposed to the insecticide had reduced polyp activity—an indication of increased stress. Shrimplike amphipods were affected, too. Even at low doses, imidacloprid exposure inhibited their movement. And for some, high levels of exposure were fatal.

他們發(fā)現(xiàn)，暴露在殺蟲劑下的珊瑚減少了水螅的活動——這是壓力增加的跡象。形似蝦的片腳類動物也受到了影響。即使是低劑量的吡蟲啉也會抑制它們的運動。對一些人來說，高水平的輻射是致命的。

Masumi Yamamuro, a biogeochemist with the Geological Survey of Japan who was not involved in the research, says that, just like honeybees, many marine animals are arthropods, and thus could be similarly vulnerable to neonics. “The disruption of marine ecosystems and the food web could be severe,” she says.

日本地質(zhì)勘測局的生物地球化學家Masumi Yamamuro沒有參與這項研究，他說，就像蜜蜂一樣，許多海洋動物都是節(jié)肢動物，因此同樣容易受到電子學的傷害。“海洋生態(tài)系統(tǒng)和食物網(wǎng)的破壞可能是嚴重的。”她說。

But when it comes to this class of insecticide, the relationship between exposure and impact is not well understood, says Michelle Hladik, an environmental chemist with the US Geological Survey who did not take part in the study. Hladik says most of the concentrations of neonics tested in Davis’s experiment were unrealistically high—beyond what is seen in the wild. But even low doses, she adds, could still be a hazard for marine life.

但美國地質(zhì)調(diào)查局(US Geological Survey)的環(huán)境化學家米歇爾赫拉迪克(Michelle Hladik)表示，在這類殺蟲劑方面，接觸量與影響之間的關(guān)系還不太清楚。赫拉迪克說，戴維斯的實驗中測試的大多數(shù)新煙堿的濃度都高得離譜，超出了野外所見的水平。但她補充說，即使是低劑量，也可能對海洋生物造成危害。

Though more research is needed to find the concentration thresholds at which neonics become harmful—something that Davis and her colleagues are trying to figure out—Hladik says their study is a step toward rectifying that gap in the knowledge.

雖然還需要更多的研究來發(fā)現(xiàn)，在濃度閾值下，新煙堿會變成有害的東西，戴維斯和她的同事們正試圖弄清楚赫拉迪克說，他們的研究是朝著糾正這種知識差距邁出的一步。