Population dynamics and biogeochemical significance of Limacina helicina antarctica in the Scotia Sea (Southern Ocean)
Population dynamics and biogeochemical significance of Limacina helicina antarctica in the Scotia Sea (Southern Ocean)
复制标题
DOI：
10.1016/j.dsr2.2011.08.003
复制
发表时间：
2012-01-01
影响因子：
3
通讯作者：
Bakker, D. C. E.
中科院分区：
文献类型：
--
作者：
Bednarsek, N.;Tarling, G. A.;Bakker, D. C. E.
南极螺旋藻是南大洋浮游动物群落中常见的一部分，但人们对其生活史知之甚少。在这里，我们确定了该物种在斯科舍海区域的种群结构和现存量生物量，并利用这些信息得出了增长率、死亡率和次级生产力的估计。在大小-频率分布上存在3个不重叠的队列：G2代(0a)，模态峰位于0.3 mm的壳径；G1代(1a)，模态峰在2.7 mm处；G代(2a)，大小在4~10 mm之间。我们推测至少有一些螺旋藻蚂蚁。能够存活3年或更长时间，平均生长速度为0.01 mm d(-1)。死亡率为0.01d(-1)或3.83年(-1)，1岁以上存活率为2%，2岁以上存活率为0.05%。现存量为178mgDWm(-2)或32mgCm(-2)，介于23mgC-orgm(-2)和9mgC-inorgm(-2)之间。无机组分的碳酸钙组成相当于72 mg CaCO3m(-2)。夏季最大日生产力为1.8mgCm(-2)d(-1)，由1.3mgOgm(-2)d(-1)和0.5mgCinorgm(-2)d(-1)组成，相当于4.2mgCaCO3m(-2)d(-1)。夏季群体比生长率(P：Bd(-1))为0.06。秋季和冬季的增长和生产似乎仍在继续，增速几乎与夏季持平。我们认为，由其他研究报告的沉淀性螺旋藻蚂蚁的秋季高峰似乎不是生命周期终止的结果，而更有可能是环境和行为因素的组合。(C)2011爱思唯尔有限公司。保留所有权利。
Limacina helicina antarctica is a common part of the Southern Ocean zooplankton community but little is known about its life cycle. Here we determine the population structure and standing stock biomass of this species in the Scotia Sea region and use this information to derive estimates for rates of growth, mortality and secondary productivity. Three non-overlapping cohorts were present in the size-frequency distribution, a G2 generation (0-year) with a modal peak at 0.3 mm shell diameter, a G1 generation (1-year) with a modal peak at 2.7 mm and a G generation (2-year) cohort with sizes between 4 and 10 mm. We surmise that at least some L. helicina ant. are capable of living 3 years or more, growing at an average rate of 0.01 mm d(-1). Mortality rates were 0.01 d(-1) or 3.83 year(-1), with 2% of individuals surviving beyond 1 year of age and 0.05% beyond 2 years of age. Standing stock biomass was 178 mg DW m(-2) or 32 mg C m(-2), divided between 23 mg C-org m(-2) and 9 mg C-inorg m(-2). The inorganic fraction had a calcium carbonate composition equivalent to 72 mg CaCO3 m(-2). Maximum daily productivity during the summer was 1.8 mg C m(-2) d(-1), made up of 1.3 C-org mg m(-2) d(-1) and 0.5 mg C-inorg m(-2) d(-1), and equivalent to 4.2 mg CaCO3 m(-2) d(-1). The mass specific growth rate (P:B d(-1)) was 0.06 within the summer period. Growth and production appeared to continue over the autumn and winter months at rates almost equivalent to those in summer. We propose that autumn peaks in sedimenting L. helicina ant., reported by other studies, do not appear to be the consequence of the termination of the life-cycle but are more likely to result from a combination of environmental and behavioural factors. (C) 2011 Elsevier Ltd. All rights reserved.