Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, NC 28409, USA.
Aquat Toxicol. 2012 Jan 15;106-107:85-94. doi: 10.1016/j.aquatox.2011.10.011. Epub 2011 Oct 28.
Blooms of the toxic alga Karenia brevis occur along coastlines where sessile suspension feeding invertebrates are common components of benthic communities. We studied the effects of K. brevis on four benthic suspension feeding invertebrates common to the coast of the SE United States: the sponge Haliclona tubifera, the bryozoan Bugula neritina, the bivalve Mercenaria mercenaria, and the tunicate Styela plicata. In controlled laboratory experiments, we determined the rate at which K. brevis was cleared from the seawater by these invertebrates, the effect of K. brevis on clearance rates of a non-toxic phytoplankton species, Rhodomonas sp., and the extent to which brevetoxins bioaccumulated in tissues of invertebrates using an enzyme-linked immunosorbent assay (ELISA). All four invertebrate species cleared significant quantities of K. brevis from seawater, with mean clearance rates ranging from 2.27 to 6.71 L g h⁻¹ for H. tubifera and S. plicata, respectively. In the presence of K. brevis, clearance rates of Rhodomonas sp. by B. neritina and S. plicata were depressed by 75% and 69%, respectively, while clearance rates by H. tubifera and M. mercenaria were unaffected. Negative effects of K. brevis were impermanent; after a recovery period of 13 h, B. neritina and S. plicata regained normal clearance rates. All four invertebrates accumulated high concentrations of brevetoxin after a 4h exposure to K. brevis, but when animals were transferred to filtered seawater for 15 h after exposure, brevetoxin concentrations in the tissues of H. tubifera and B. neritina decreased by ∼80%, while there was no change in toxin concentration in the tissues of S. plicata and M. mercenaria. High cell concentrations of K. brevis may cause a suppression of clearance rates in benthic suspension feeding invertebrates, resulting in a positive feedback for bloom formation. Also, high concentrations of toxin may accumulate in the tissues of benthic suspension feeding invertebrates that may be transferred to higher-level consumers.
短裸甲藻（Karenia brevis）的水华经常出现在有固着滤食无脊椎动物栖息的沿海地区，这些无脊椎动物是底栖群落的常见组成部分。我们研究了短裸甲藻对美国东南沿海地区四种常见的底栖滤食无脊椎动物的影响：海绵 Haliclona tubifera、苔藓虫 Bugula neritina、双壳类 Mercenaria mercenaria 和被囊动物 Styela plicata。在受控的实验室实验中，我们确定了这些无脊椎动物从海水中清除短裸甲藻的速度、短裸甲藻对非毒性浮游植物 Rhodomonas sp. 清除率的影响，以及酶联免疫吸附测定（ELISA）法检测到的生物累积在无脊椎动物组织中的赤潮毒素量。所有四种无脊椎动物都能从海水中大量清除短裸甲藻，H. tubifera 和 S. plicata 的平均清除率分别为 2.27 至 6.71 L g h ⁻¹ 。在短裸甲藻存在的情况下，B. neritina 和 S. plicata 对 Rhodomonas sp. 的清除率分别下降了 75%和 69%，而 H. tubifera 和 M. mercenaria 的清除率则不受影响。短裸甲藻的负面影响是暂时的；在 13 小时的恢复期后，B. neritina 和 S. plicata 恢复了正常的清除率。四种无脊椎动物在暴露于短裸甲藻 4 小时后都积累了高浓度的赤潮毒素，但当动物在暴露后 15 小时转移到过滤海水中时，H. tubifera 和 B. neritina 组织中的赤潮毒素浓度下降了约 80%，而 S. plicata 和 M. mercenaria 组织中的毒素浓度则没有变化。短裸甲藻的高细胞浓度可能会导致底栖滤食无脊椎动物的清除率下降，从而对水华的形成产生正反馈。此外，赤潮毒素可能会在底栖滤食无脊椎动物的组织中积累，然后转移到更高营养级的消费者中。
Zotero 插件