Sedimentation of Nodularia spumigena and distribution of nodularin in the food web during transport of a cyanobacterial bloom from the Baltic Sea to the Kattegat
Sedimentation of Nodularia spumigena and distribution of nodularin in the food web during transport of a cyanobacterial bloom from the Baltic Sea to the Kattegat
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DOI：
10.1016/j.hal.2019.05.005
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发表时间：
2019-06-01
期刊：
影响因子：
6.6
通讯作者：
Rita, Diego
中科院分区：
文献类型：
--
作者：
Carlsson, Per;Rita, Diego
球芽藻是一种有毒的蓝藻，每年在波罗的海大量繁殖。在波罗的海的半咸淡水中，它的毒素结核素主要影响地表水中的生物群，因为这种物种具有天然的浮力。然而，毒素的命运是未知的，一旦蓝藻开花进入卡特加特的咸水。为了研究这一知识差距，科学家们跟踪研究了一种浮藻，它被表面洋流从波罗的海带到卡特加特地区，穿过厄勒海峡。在水华过程中，spumigena细胞通过水柱的细胞浓度增加(高达130 10(3)个细胞ml(-1))，在20米深的水坡下可以发现细胞(4.2 10（3)个细胞ml(-1)）。从高背斜下方（10-12 m深度）采集的沉降捕集器样本也显示，在水华期间，褐藻丝的沉降有所增加。在水样（0.3 ~ 6.0 μ g / l(-1)）、沉积物样品（毒素积累速率为20 μ g / d(-1)）、浮游动物（桡足类可达0.1 μ g / d(-1)）、蓝贻贝（70 ~ 230 μ g / kg(-1) DW）、远洋和底栖鱼类(鲱鱼（肌肉或肝脏1.0 ~ 3.4 μ g / kg(-1) DW）和比目鱼(肌肉1.3 ~ 6.2 μ g / kg（-1) DW，肝脏11.7 ~ 26.3 μ g / kg(-1) DW）中均检测到瘤素毒素。一项实验室实验表明，随着盐度的增加，褐藻丝的浮力下降，在最高盐度（32 PSU）下，它们甚至以高达1.7 m / d（-1）的速度下沉。这对咸淡水蓝藻繁殖的命运有影响，当它们到达更咸的水域时。可以推测，在这种情况下，相当一部分结核素华含量会到达底栖生物，而在微咸水中，大部分华被认为在地表水中分解。
Nodularia spumigena is a toxic cyanobacteria that blooms in the Baltic Sea every year. In the brackish water of the Baltic Sea, its toxin, nodularin, mainly affects the biota in the surface water due to the natural buoyancy of this species. However, the fate of the toxin is unknown, once the cyanobacteria bloom enters the more saline waters of the Kattegat. In order to investigate this knowledge gap, a bloom of N. spumigena was followed during its passage, carried by surface currents, from the Baltic Sea into the Kattegat area, through the Oresund strait. N. spumigena cells showed an increased cell concentration through the water column during the passage of the bloom (up to 130 10(3) cells ml(-1)), and cells (4.2 10(3) cells ml(-1)) could be found down to 20m depth, below a pycnocline. Sedimentation trap samples from below the pycnocline (10-12 m depth) also showed an increased sedimentation of N. spumigena filaments during the passage of the bloom. The toxin nodularin was detected both in water samples (0.3-6.0 mu g l(-1)), samples of sedimenting material (a toxin accumulation rate of 20 mu g day(-1)), zooplankton (up to 0.1 ng ind(-1) in copepods), blue mussels (70-230 mu g kg(-1) DW), pelagic and benthic fish (herring (1.0-3.4 mu g kg(-1) DW in herring muscle or liver) and flounder (1.3-6.2 mu g kg(-1) DW in muscle, and 11.7-26.3 mu g kg(-1) DW in liver). A laboratory experiment showed that N. spumigena filaments developed a decreased buoyancy at increased salinities and that they were even sinking with a rate of up to 1,7 m day(-1) at the highest salinity (32 PSU). This has implications for the fate of brackish water cyanobacterial blooms, when these reach more saline waters. It can be speculated that a significant part of the blooms content of nodularin will reach benthic organisms in this situation, compared to blooms decaying in brackish water, where most of the bloom is considered to be decomposed in the surface waters.