Sediment hardness and water temperature affect the burrowing of Echinocardium cordatum: Implications for mass mortality during the 2011 earthquake-liquefaction-tsunami disaster
Sediment hardness and water temperature affect the burrowing of Echinocardium cordatum: Implications for mass mortality during the 2011 earthquake-liquefaction-tsunami disaster
复制标题
沉积物硬度和水温影响 Echinocardium cordatum 的洞穴：对 2011 年地震液化海啸灾难期间大规模死亡的影响
DOI：
10.1016/j.ecss.2022.107763
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kubota Kaoru
中科院分区：
文献类型：
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作者：
Seike Koji;Sassa Shinji;Shirai Kotaro;Kubota Kaoru
心脏海胆Echinococcus cordatum是一种重要的生物扰动在世界各地的浅海环境。虽然已知硬沉积物和低水温会降低底栖无脊椎动物的穴居能力，但这些因素对E. cordatum是最重要的生物扰动源之一，至今仍不为人所知。在这里，我们量化了挖掘能力（即，穴居时间），这一物种在水族馆沉积物硬度和水温是人为控制。水族箱试验结果表明，底质硬度和水温均显著地影响了赤眼蜂的挖洞时间。心脏两个因素之间没有显著的相互作用。在硬泥沙和低温（10 °C）条件下，E.在20 °C的高温下，沉积物中的二氧化碳浓度约为20 °C时的3.5倍。由于在低温下液化硬化沉积物中的挖掘时间与地震发生和海啸第一次到达之间的现场观察间隔进行了比较。这些结果为2011年东北地震后太平洋沿岸观察到的物种大规模死亡率以及2011年3月11日的液化和海啸事件提供了有用的见解。在当时，迅速重新挖掘是至关重要的，以防止个人在被海底液化从海底沉积物中排出后被海啸海流冲走。结果表明，E.因此，海底沉积物很难重新钻入海底沉积物中，从而容易受到海啸海流的影响。这将导致心脏海胆的观察大规模死亡和长期缺席的地区后，灾难。
The heart urchinEchinocardium cordatumis an important bioturbator in shallow marine environments throughout the world. Although hard sediment and low water temperature are known to decrease the burrowing ability of benthic invertebrates, the effect of these factors onE. cordatum, one of the most important bioturbators, has remained unknown. Here, we quantified the burrowing ability (i.e., burrowing time) of this species in an aquarium where sediment hardness and water temperature were artificially controlled. The aquarium experiment revealed that both sediment hardness and water temperature significantly affected the burrowing time ofE. cordatum. No significant interactions were detected between the two factors. Under hard-sediment and low-temperature (10 °C) conditions, reburrowing times forE. cordatumwere around 3.5 times longer than with soft sediment and high temperatures (20 °C). The burrowing time in the hardened sediment due to liquefaction at low temperatures was compared with the observed in-situ interval between the occurrence of an earthquake and the first arrival of a tsunami. The results provide useful insights into the mass mortality of the species that was observed on the Pacific coast after the 2011 Tohoku Earthquake and associated liquefaction and tsunami events on March 11, 2011. Rapid reburrowing would have been vital at the time to prevent individuals from being swept away by tsunami currents after being expelled from the seafloor sediments by the seabed liquefaction. However, our results indicated thatE. cordatumwould not have been able to easily reburrow into the seafloor sediment, thereby becoming vulnerable to tsunami currents. This would have resulted in the heart urchin's observed mass mortality and prolonged absence from the region after the disaster.