High-Resolution Sampling of a Broad Marine Life Size Spectrum Reveals Differing Size- and Composition-Based Associations With Physical Oceanographic Structure
High-Resolution Sampling of a Broad Marine Life Size Spectrum Reveals Differing Size- and Composition-Based Associations With Physical Oceanographic Structure
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DOI：
10.3389/fmars.2020.542701
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发表时间：
2020-12-22
影响因子：
3.7
通讯作者：
Penta, Bradley
中科院分区：
文献类型：
--
作者：
Greer, Adam T.;Lehrter, John C.;Penta, Bradley
观察多种大小类别的生物，沿着海洋学特性和水团起源，可以提高我们对聚集驱动因素的理解，但获得这些测量结果仍然是生物海洋学的一个根本挑战。通过部署多个生物采样系统，从传统的瓶和净采样，在原位成像和声学，我们描述了不同大小的类的海洋生物（几微米到类似于10厘米）的空间格局与当地和区域（米到公里）的物理海洋学条件的特拉华州大陆架。部署的成像和声学系统包括（按目标生物体大小的升序排列）成像流式细胞仪（CytoSense）、数字全息成像系统（HOLOCAM）、原位浮游鱼类成像系统（ISIIS，2台具有不同像素分辨率的相机）和多频声学（SIMRAD，18和38 kHz）。不同系统生成的空间模式显示出大小相关的聚集以及与水平和垂直盐度和温度梯度的不同联系，这是传统的基于站点的采样（类似于9公里分辨率）无法检测到的。两个ISIIS相机的直接比较表明，组成和空间斑块的变化，取决于生物体的大小，形态和相机像素分辨率。靠近海面的大型浮游动物，主要由浮游动物和凝胶状生物组成，往往在陆架断裂附近的近海更丰富。这一地区也与高浮游植物生物量和较高的整体生物丰度在ISIIS，声学和有针对性的净采样。相比之下，近岸区域主要是由硬体浮游动物，并有相对较低的声学后向散射。这些网显示了一个以桡足类为主的群落，但它们也显示出在近海区域软体生物的相对丰度较高，这些生物是由ISIIS量化的。HOLOCAM检测到密集的纤毛虫斑块，这些纤毛虫太小，无法在渔网或ISIIS图像中捕捉到。这种几乎同时部署不同的系统，使不同的生物体大小类的空间格局的描述，它们的空间关系，潜在的猎物和捕食者，以及它们与特定的海洋条件的关联。这些数据集也可用于评估采样技术的有效性，最终有助于设计有效的，假设驱动的采样程序，将这些互补技术。
Observing multiple size classes of organisms, along with oceanographic properties and water mass origins, can improve our understanding of the drivers of aggregations, yet acquiring these measurements remains a fundamental challenge in biological oceanography. By deploying multiple biological sampling systems, from conventional bottle and net sampling to in situ imaging and acoustics, we describe the spatial patterns of different size classes of marine organisms (several microns to similar to 10 cm) in relation to local and regional (m to km) physical oceanographic conditions on the Delaware continental shelf. The imaging and acoustic systems deployed included (in ascending order of target organism size) an imaging flow cytometer (CytoSense), a digital holographic imaging system (HOLOCAM), an In Situ lchthyoplankton Imaging System (ISIIS, 2 cameras with different pixel resolutions), and multi-frequency acoustics (SIMRAD, 18 and 38 kHz). Spatial patterns generated by the different systems showed size-dependent aggregations and differing connections to horizontal and vertical salinity and temperature gradients that would not have been detected with traditional stationbased sampling (similar to 9-km resolution). A direct comparison of the two ISIIS cameras showed composition and spatial patchiness changes that depended on the organism size, morphology, and camera pixel resolution. Large zooplankton near the surface, primarily composed of appendicularians and gelatinous organisms, tended to be more abundant offshore near the shelf break. This region was also associated with high phytoplankton biomass and higher overall organism abundances in the ISIIS, acoustics, and targeted net sampling. In contrast, the inshore region was dominated by hard-bodied zooplankton and had relatively low acoustic backscatter. The nets showed a community dominated by copepods, but they also showed high relative abundances of soft-bodied organisms in the offshore region where these organisms were quantified by the ISIIS. The HOLOCAM detected dense patches of ciliates that were too small to be captured in the nets or ISIIS imagery. This near-simultaneous deployment of different systems enables the description of the spatial patterns of different organism size classes, their spatial relation to potential prey and predators, and their association with specific oceanographic conditions. These datasets can also be used to evaluate the efficacy of sampling techniques, ultimately aiding in the design of efficient, hypothesisdriven sampling programs that incorporate these complementary technologies.