Macrobenthic community structure within and beneath the oxygen minimum zone, NW Arabian Sea
Macrobenthic community structure within and beneath the oxygen minimum zone, NW Arabian Sea
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DOI：
10.1016/s0967-0645(99)00103-4
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发表时间：
2000-01-01
影响因子：
3
通讯作者：
Lamont, PA
中科院分区：
文献类型：
--
作者：
Levin, LA;Gage, JD;Lamont, PA
1994年秋季，在阿拉伯海西北部阿曼边缘的最低含氧带（OMZ，< 0.5 ml l（-1））内和之下进行了大型底栖动物调查。六站（400，700，850，1000，1250和3400米）的特点是大型底栖动物丰度，生物量，身体大小，分类组成，多样性和生活方式，以及这些参数与环境条件的关系。OMZ（400-1000 m）以密集（5818- 19，183 ind m（-2））软体动物组合为主，主要（86-99%）由表面摄食的多毛类、Spionids和cirratulids组成，在400-和700-m站占主导地位，在850-和1000-m站占主导地位。软体动物和大多数甲壳类动物只在大洋区以下（大于或等于1 250米）才常见;然而，在大洋区内有大量的片足类Ampelisca。密度和生物量都升高OMZ内相对于站以下，但身体大小没有显着差异站。较低的OMZ边界（0.5毫升升（-1））是不是一个区域的大型底栖动物常设资源，作为最初的假设。然而，700- 850 m处的丰度最大值可能反映了氧气阈值（0.15-0.20 ml l（-1）），高于该阈值，大型动物会利用有机富集的沉积物。在OMZ以下，挖洞和底栖觅食的发生率增加，物种丰富度（E[S（100）]）、多样性（H '）和均匀度（J'）均低于OMZ以下，优势度（R1 D）高于OMZ以下。站内（boxcore之间）动物的异质性显着增加以下的OMZ。表面沉积物色素浓度和氧气共同解释了整个样带E[S（100）]、H'和J'测量值96-99%的方差;粒度和% TOC没有产生显著的回归。色素，假设反映食物的可用性和可能的氧气对有机质保存的影响，与物种丰富度和均匀度呈负相关，与优势度呈正相关。水深的情况正好相反。阿曼边缘OMZ（0.13-0.3 ml（-1））内的大型底栖生物钙化模式和生活方式与古环境重建模型的缺氧生物相匹配。(C)1999 Elsevier Science Ltd.保留所有权利。
Investigations of macrobenthos were carried out within and beneath the oxygen minimum zone (OMZ, < 0.5 ml l(-1)) during Fall 1994 on the Oman margin, NW Arabian Sea. Six stations (400, 700, 850, 1000, 1250 and 3400m) were characterized with respect to macrofaunal abundance, biomass, body size, taxonomic composition, diversity and lifestyles, and the relation of these parameters to environmental conditions. The OMZ (400-1000 m) was dominated by a dense (5818-19,183 ind m(-2)), soft-bodied assemblage consisting largely (86-99%) of surface-feeding polychaetes, Spionids and cirratulids dominated at the 400- and 700-m stations, paraonids and ampharetids at the 850- and 1000-m stations. Molluscs and most crustaceans were common only below the OMZ ( greater than or equal to 1250 m); a species of the amphipod Ampelisca was abundant within the OMZ, however. Both density and biomass were elevated within the OMZ relative to stations below but body size did not differ significantly among stations. The lower OMZ boundary (0.5 ml l(-1)) was not a zone of enhanced macrofaunal standing stock, as originally hypothesized. However, abundance maxima at 700-850m may reflect an oxygen threshold (0.15-0.20 ml l(-1)) above which macrofauna take advantage of organically enriched sediments. Incidence of burrowing and subsurface-deposit feeding increased below the OMZ, Species richness (E[S(100)]), diversity (H') and evenness (J') were lower and dominance (R1D) was higher within than beneath the OMZ. Within-station (between-boxcore) faunal heterogeneity increased markedly below the OMZ. Surface sediment pigment concentrations and oxygen together explained 96-99% of the variance in measures of E[S(100)], H' and J' across the transect; grain size and % TOC did not yield significant regressions. Pigments, assumed to reflect food availability and possibly oxygen effects on organic matter preservation, were negatively correlated with species richness and evenness, and positively correlated with dominance. The reverse was true for water depth. Macrobenthic patterns of calcification and lifestyle within the Oman margin OMZ (0.13-0.3 mi l(-1)) match the dysaerobic biofacies of paleo-environmental reconstruction models. (C) 1999 Elsevier Science Ltd. All rights reserved.