海底微生物群落還未走出26年前的一場模擬深海采礦

Sediment samples,collected by a remotely operated vehicle off the coast of Peru(shown),reveal that seafloor microbe communities still haven’t recovered from an experiment 26 years ago that mimicked deep-sea mining.

由秘魯海岸附近的一輛遙控汽車收集的沉積物樣本表明，海底微生物群落仍未從26年前的模擬深海采礦的實(shí)驗中恢復(fù)。

Microbe communities living in the seafloor off Peru haven’t bounced back from a deep-sea mining experiment 26 years ago.The populations are still reduced by 30 percent in this part of the South Pacific Ocean,researchers report April 29 in Science Advances.

生活在秘魯海底的微生物群落還沒有從26年前的深海采礦試驗中恢復(fù)過來。研究人員在4月29日的《Science Advances》雜志上報告說，南太平洋這部分海域的微生物數(shù)量仍然減少了30%。

From 1989 to 1994,the DISturbance and reCOLonization,or DISCOL,experiment plowed grooves into the seafloor to mimic deep-sea mining for valuable metal-bearing rocks.The lumps of rock,known as polymetallic or manganese nodules,contain economically important metals such as copper,nickel and cobalt.

從1989年到1994年，DISCOL實(shí)驗在海底開槽，模擬深海采礦，開采有價值的含金屬的巖石。這些塊狀巖石(稱為多金屬結(jié)核或錳結(jié)核)包含經(jīng)濟(jì)上重要的金屬，例如銅，鎳和鈷。

To recover the nodules,miners dredge the seafloor,scraping off much of the top layer of sediment along with the rocks.Researchers have long expressed concern about how this might affect deep-sea ecosystems(SN:2/19/14).But there is little data about the effects of deep-sea mining on the ocean environment—and particularly on the microbes at the base of the food web,which cycle the nutrient nitrogen between seafloor and bottom waters(SN:10/10/17).

為了找到這些多金屬結(jié)核，礦工們在海底挖掘，刮掉巖石表層的大部分沉積物。長期以來，研究人員一直擔(dān)心這可能會影響深海生態(tài)系統(tǒng)(SN：2/19/14).但是，幾乎沒有關(guān)于深海采礦對海洋環(huán)境的影響的數(shù)據(jù)，尤其是對食物網(wǎng)底部微生物的影響，這些微生物在海底和海底水域之間循環(huán)養(yǎng)分氮(SN:10/10/17).

Scientists last assessed DISCOL’s effects in 1996.So in 2015,microbial ecologist Tobias Vonnahme,now of The Arctic University of Norway in Troms?,and colleagues devised a new test,comparing the 26-year-old plough tracks with five-week-old tracks they dug into the seafloor.

科學(xué)家最后一次評估DISCOL對生態(tài)系統(tǒng)的影響是在1996年。所以在2015年，微生物生態(tài)學(xué)家Tobias Vonnahme和他的同事們設(shè)計了一項新的測試，將26年的犁溝和他們在海床上挖出的五周的犁溝進(jìn)行比較。

Cell counts of microbes in the younger tracks were reduced by about 50 percent compared with undisturbed areas;in older tracks,cell numbers were reduced by about 30 percent.Due to slow accumulation of sediment in the deep sea,regions disturbed by mining could take more than 50 years to fully recover,the team says.

與未受干擾的地區(qū)相比，較年輕地區(qū)的微生物數(shù)量減少了約50%;在較老的受干擾地區(qū)中，微生物數(shù)量減少了約30%。研究小組說，由于深海中沉積物的緩慢堆積，受采礦干擾的地區(qū)可能需要超過50年的時間才能完全恢復(fù)。