Seasonal distribution of genetic types of planktonic foraminifer morphospecies in the Santa Barbara Channel and its paleoceanographic implications
Seasonal distribution of genetic types of planktonic foraminifer morphospecies in the Santa Barbara Channel and its paleoceanographic implications
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DOI：
10.1029/2001pa000723
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发表时间：
2003-05-09
期刊：
影响因子：
--
通讯作者：
Pak, D
中科院分区：
文献类型：
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作者：
Darling, KF;Kucera, M;Pak, D
我们提供了1999年在圣巴巴拉海峡收集的浮游有孔虫基因型（小亚基（SSU）核糖体(r) RNA基因）和形态种（沉积物陷阱）的时间分布数据。取样的重点是古海洋学上重要的形态种，主要是球形球虫。我们发现，在整个年周期中，与该地区相关的所有变化的水文制度中，除了1月份外，都有相同的基因型（IId型），当时我们记录了高纬度IIa型的额外存在。我们鉴定出三种新的基因型：新红舌象i型、厚皮象右旋II型和quinqueloba Turborotalita i型。我们的数据表明，大泡金蝇IId型甚至可能是上面列出的新基因型可能与该地区复杂的水文或其他环境特征有关。由于i型球藻全年都有发生，其峰值通量与不同的水文制度有关，因此我们认为水柱的物理性质不是影响该基因型分布和生长的主要因素。在沉积物捕集器样本中，我们发现了一个倾斜的盘绕比（最有可能代表IId型），这与海面温度和基因型差异无关。这项研究说明了绘制遗传类型的空间和时间分布图的必要性，特别是在对地球化学和古生物学代用物进行校准的古海洋学领域。
[1] We present data on the temporal distribution of planktonic foraminifer genotypes ( small subunit (SSU) ribosomal (r) RNA gene) and morphospecies ( sediment traps) collected during 1999 in the Santa Barbara Channel. The sampling was undertaken with special emphasis on paleoceanographically important morphospecies, predominantly Globigerina bulloides. We found the same genotype of G. bulloides ( type IId) in all the changing hydrographic regimes associated with this region throughout the annual cycle with the exception of January, when we recorded the additional presence of the high-latitude G. bulloides type IIa. We identified three new genotypes: Neogloboquadrina dutertrei type Ic, N. pachyderma dextral type II, and Turborotalita quinqueloba type IId. Our data suggest that G. bulloides type IId and possibly even the new genotypes listed above may be associated specifically with the complex hydrography or other environmental features characteristic of this area. Since G. bulloides type IId occurs throughout the year and its peak fluxes are related to different hydrographic regimes, we argue that the physical properties of the water column are not the major factor influencing the distribution and growth of this genotype. In sediment trap samples we found a skewed coiling ratio for G. bulloides ( most likely representing type IId), which is related neither to sea surface temperature nor to genotypic difference. This study illustrates the necessity to map both the spatial and temporal distribution of the genetic types, especially in areas of paleoceanographic interest, where geochemical and paleontological proxies are being calibrated.