Abundance and Production Rates of Heterotrophic Bacterioplankton in the Context of Sediment and Water Column Processes in the Chukchi Sea
Abundance and Production Rates of Heterotrophic Bacterioplankton in the Context of Sediment and Water Column Processes in the Chukchi Sea
复制标题
DOI：
10.5670/oceanog.2015.59
复制
发表时间：
2015-09-01
期刊：
影响因子：
2.8
通讯作者：
Grebmeier, Jacqueline M.
中科院分区：
文献类型：
--
作者：
Cooper, Lee W.;Savvichev, Alexander S.;Grebmeier, Jacqueline M.
细菌产量和丰度与楚科奇海水柱和底层底栖生物中生物产量高的地区有关。在俄罗斯-美国北极长期普查（RUSALCA）计划期间进行的过程测量，例如沉降颗粒有机物和沉积物有机物的碳同位素组成，用于将细菌生产和丰度置于背景中。这些测量结果表明，有垂直梯度的水柱和沉积物中的有机物质的稳定碳同位素组成是显着不同的上覆水柱中的沉积物质。水柱内的差异可能反映了夏末生产力的下降，增加了对C-13的歧视，也提供了水柱和底层沉积物中碳代谢的迹象。在RUSALCA计划期间，还观察到表层沉积物中有机物的稳定碳同位素组成以及有机物中的C/N比的时间变化，特别是楚科奇海岸附近某些站点的C-13/C-12比较高，而阿拉斯加霍普角附近的C-13/C-12比较低。自2004年以来，楚科奇海中南部生产地点的C/N比值有所增加，这表明有机物质沉积发生了变化。俄罗斯-美国联合巡航的部分或全部十年系列研究的其他参数包括沉积物需氧量、有机物的氮同位素组成、沉积物粒度、表层沉积物中的叶绿素含量以及表层沉积物中碳和氮的元素比。这些过程的测量结果支持这样的解释，即生态系统显示出细菌和初级生产与底层底栖生物之间的强烈耦合。
Bacterial production and abundance are linked to areas of high biological production in the water column and in the underlying benthos in the Chukchi Sea. Process measurements taken during the Russian American Long-term Census of the Arctic (RUSALCA) program, such as the carbon isotope composition of sinking particulate organic matter and sediment organic matter, are used to put bacterial production and abundance in context. These measurements show that there are vertical gradients in the water column and that the stable carbon isotope composition of organic materials in the sediments is significantly different from sedimenting materials in the overlying water column. Differences within the water column likely reflect late summer declines in productivity that increase discrimination against C-13 and also provide indications of carbon metabolism in the water column and underlying sediments. Temporal changes in the stable carbon isotope composition of organic matter in surface sediments, as well as C/N ratios in organic matter during the RUSALCA program, are also being observed, specifically higher ratios of C-13/C-12 at some stations near the Chukotka coast, and lower ratios of C-13/C-12 near Point Hope, Alaska. C/N ratios have increased since 2004 at productive sites in the south central Chukchi Sea, suggesting changes in organic material deposition. Other parameters studied on some or all of the decadal series of joint Russia-US cruises include sediment oxygen demand, the nitrogen isotopic composition of organic matter, sediment grain size, chlorophyll content in surface sediments, and elemental ratios of carbon and nitrogen in surface sediments. These process measurements support interpretations that the ecosystem shows strong coupling between bacterial and primary production and the underlying benthos.