During the 6th Chinese Arctic Expedition in August 2014, samples from melting ponds, sea ice, and the underlying sea water at seven ice camps in Canada Basin were collected, and the characteristics of the bacterial and protist communities were analyzed using epifluorescence microscopy. The results showed the first and second dominant groups were bacteria and heteroflagellates, respectively, with biomass percentages of 42.8%, 37.8%, 50.7%, 40.2%, 34.3%,37.5%, respectively (data from the ICE07 melting pond with an algal bloom were not included). Heterotrophic organisms such as bacteria, heteroflagellates, and ciliates dominated within the community, suggesting that the microbial loop might play an important role in the community of the pack ice zone. Under the background of rapid melting of sea ice in austral summer, the environments of all three habitats were unsuitable for rapid growth of the community and the biomass was very low. An autotrophic flagellate bloom was observed in a melting pond and within the upper 20 cm of the ice column at ICE07. We suggest that suitable quantities of both algal seed and nutrient supplement are essential for the occurrence of algal blooms on surface ice.%采用表面荧光显微分析方法对2014年夏季中国第6次北极科学考察期间采集于加拿大海盆7个海冰站位的融池、冰芯和冰下海水样品进行了细菌和原生生物群落分析.结果表明,上述3类生境中的第一优势类群均为细菌(不包括ICE07站位出现水华融池的统计),分别占总生物量的42.8%、37.8%和50.7%;第二优势类群均为鞭毛虫,分别占总生物量的40.2%、34.3%和37.5%.包含细菌、鞭毛虫和纤毛虫在内的异养生物在总生物量中占有优势,显示微食物环在其中起着重要作用.在北冰洋夏季快速融冰的背景下,3类生境总体上缺少快速生长的条件,总生物量偏低.其中ICE07站位出现融池水华和冰表自养鞭毛藻高值,推测合适的藻种和营养盐的额外补充共同促成了该站位冰表(融池)藻华的形成.
展开▼
