Dynamics of meiofaunal assemblages on the continental shelf and deep-sea sediments of the Cretan Sea (NE Mediterranean) : relationships with seasonal changes in food supply
Dynamics of meiofaunal assemblages on the continental shelf and deep-sea sediments of the Cretan Sea (NE Mediterranean) : relationships with seasonal changes in food supply
复制标题
克里特海（地中海东北部）大陆架和深海沉积物上小型动物群落的动态：与食物供应季节变化的关系
DOI：
10.1016/s0079-6611(00)00026-4
复制
发表时间：
2000
影响因子：
4.1
通讯作者：
N. D. Croce
中科院分区：
文献类型：
--
作者：
R. Danovaro;A. Tselepides;A. Otegui;N. D. Croce
从三个大陆架（在40，100和200米深度）和四个深海站（在540，700，940和1540米深度）在爱琴海（南爱琴海，东北地中海）后生动物小型底栖动物丰度和生物量的定量信息。使用多芯取样器按季节（1994年8月至1995年9月）采集了样品。与所报告的深海沉积物的极低数值形成对比的是，北冰洋大陆架小型底栖动物的丰度和生物量很高，而深海沉积物的数值与深海和深海环境的数值相当。为了解释后生动物小型底栖动物的空间和季节变化，将这些数据与以下数据进行了比较：（1）“食物指标”（如蛋白质、脂质、可溶性碳水化合物和CPE）的浓度;（2）细菌生物量;（3）固定站（D 7，1 540米深）不稳定有机化合物向海底的通量。小型底栖动物参数与CPE、蛋白质和脂肪含量以及细菌生物量之间存在极显著的相关性，而大多数食物质量和数量指标（CPE、蛋白质和碳水化合物）都表现出明显的季节性，2月份最高，9月份最低。这种变化在大陆架上比在更深的深处更为明显。在大陆架上，小型底栖动物密度的显着季节性变化与不稳定有机碳的输入变化有关，而深海站的小型底栖动物组合显示出滞后的变化，以响应95年2月记录的食物输入。在所有深海站，小型底栖动物密度增加的时滞为2个月。时间滞后的小型底栖动物对食物投入的反应的指标也提供了无节幼体密度在1995年5月期间的增加和线虫，桡足类和多毛类的个体生物量在1995年2月至5月之间的增加。深海小型底栖动物密度没有明显的季节性变化，这表明500米以下的有机物供应不足以支持大型小型底栖动物的发展。在700米深度以下，沉积物中总生物量的>92%由细菌代表。细菌与小型底栖生物生物量的比率随着水深的增加而增加，这表明细菌在利用难降解有机化合物方面可能比小型底栖生物更有效。这些数据使我们假设克里特海的深海沉积物在很大程度上取决于海底微生物循环。
Quantitative information on metazoan meiofaunal abundance and biomass was obtained from three continental shelf (at 40, 100 and 200 m depth) and four deep-sea stations (at 540, 700, 940 and 1540 m depth) in the Cretan Sea (South Aegean Sea, NE Mediterranean). Samples were collected on a seasonal basis (from August 1994 to September 1995) with the use of a multiple corer. Meiofaunal abundance and biomass on the continental shelf of the Cretan Sea were high, in contrast to the extremely low values reported for the bathyal sediments that showed values comparable to those reported for abyssal and hadal environments. In order to explain the spatial and seasonal changes in metazoan meiofauna these data were compared with: (1) the concentrations of ‘food indicators’ (such as proteins, lipids, soluble carbohydrates and CPE) (2) the bacterial biomass (3) the flux of labile organic compounds to the sea floor at a fixed station (D7, 1540 m depth). Highly significant relationships between meiofaunal parameters and CPE, protein and lipid concentrations and bacterial biomass were found. Most of the indicators of food quality and quantity (such as CPE, proteins and carbohydrates) showed a clear seasonality with highest values in February and lowest in September. Such changes were more evident on the continental shelf rather than at deeper depths. On the continental shelf, significant seasonal changes in meiofaunal density were related to changes in the input of labile organic carbon whereas meiofaunal assemblages on the deep-sea stations showed time-lagged changes in response to the food input recorded in February 95. At all deep-sea stations meiofaunal density increased with a time lag of 2 months. Indications for a time-lagged meiofaunal response to the food inputs were also provided by the increase in nauplii densities during May 95 and the increase in individual biomass of nematodes, copepods and polychaetes between February and May 1995. The lack of strong seasonal changes in deep sea meiofaunal density suggests that the supply of organic matter below 500 m is not strong enough to support a significant meiofaunal development. Below 700 m depth >92% of the total biomass in the sediment was represented by bacteria. The ratio of bacterial to meiofaunal biomass increased with increasing water depth indicating that bacteria are probably more effective than meiofauna in exploiting refractory organic compounds. These data lead us to hypothesise that the deep-sea sediments of the Cretan Sea are largely dependent upon a benthic microbial loop.