A depocenter of organic matter at 7800 m depth in the SE Pacific Ocean |
| |
| Authors: | R Danovaro N Della Croce A Dell&#x;Anno A Pusceddu |
| |
| Institution: | a Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy;b Department for Study of the Territory and its Resources (DIPTERIS), University of Genoa, Corso Rainusso, 14, 16026, S. Margherita L. (, Genoa), Italy |
| |
| Abstract: | The Atacama trench, the deepest ecosystem of the southern Pacific Ocean (ca. 8000 m depth) was investigated during the Atacama Trench International Expedition. Sediments, collected at three bathyal stations (1040–1355 m depth) and at a hadal site (7800 m) were analyzed for organic matter quantity and biochemical composition (in terms of phytopigments, proteins, carbohydrates and lipids), bacterial abundance, biomass and carbon production and extracellular enzymatic activities. Functional chlorophyll-a (18.0±0.10 mg m−2), phytodetritus (322.2 mg m−2) and labile organic carbon (16.9±4.3 g C m−2) deposited on surface sediments at hadal depth (7800 m) reached concentrations similar to those encountered in highly productive shallow coastal areas. High values of bacterial C production and aminopeptidase activity were also measured (at in situ temperature and 1 atm). The chemical analyses of the Atacama hadal sediments indicate that this trench behaves as a deep oceanic trap for organic material. We hypothesize that, despite the extreme physical conditions, benthic microbial processes might be accelerated as a result of the organic enrichment. |
| |
| Keywords: | Hadal sediments Trench Bacterial production Enzymatic activities Organic matter |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
