Hendrick Vicki J, Hutchison Zoë L, Last Kim S
Scottish Association for Marine Science (SAMS), Oban, PA37 1QA, United Kingdom.
PLoS One. 2016 Feb 22;11(2):e0149114. doi: 10.1371/journal.pone.0149114. eCollection 2016.
The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura), the queen scallop (Aequipecten opercularis) and the sea squirt (Ciona intestinalis) were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris) and the anemone (Sagartiogeton laceratus), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa). With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. laceratus increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps unsurprisingly, the greatest ability to emerge from burial in all other species was from shallow (2 cm) burial. Although survival was consistently highly dependent on duration and depth of burial as expected, emergence behaviour was not as easily predictable thereby confounding predictions. We conclude that responses to burial are highly species specific and therefore tolerance generalisations are likely to be oversimplifications. These data may be used to inform environmental impact models that allow forecasting of the cumulative impacts of seabed disturbance and may provide mitigation measures for the sustainable use of the seabed.
海洋环境中含有悬浮颗粒物，其来源既有自然的，也有人为的。这种物质的沉降会使底栖生物容易受到窒息的威胁，特别是在掩埋突然发生时，比如在风暴之后或进行疏浚等活动时。它们的生存将取决于对掩埋的耐受能力以及从掩埋中逃脱的能力。在此，我们展示了一项多因素实验的数据，该实验测量了包括持续时间、沉积物粒度和深度在内的掩埋反应。选取了六种在富含沉积物的环境中常见的大型无脊椎动物，因其具有商业和/或保护价值。评估结果显示，蛇尾（Ophiura ophiura）、皇后扇贝（Aequipecten opercularis）和海鞘（Ciona intestinalis）对掩埋都高度不耐受，而绿海胆（Psammichinus miliaris）和海葵（Sagartiogeton laceratus）对掩埋的不耐受程度分别处于中等和较低水平。最不耐受掩埋但存活率很高的是罗斯蠕虫（Sabellaria spinulosa）。除了C. intestinalis外，对于所有评估的物种，随着掩埋持续时间和深度的增加以及沉积物粒度变细，死亡率都会上升。对于C. intestinalis，发现掩埋深度和沉积物粒度无关紧要，因为所有被掩埋超过一天的标本全部死亡。在评估掩埋后的出现情况时，O. ophiura出现的频率最高，其次是P. miliaris。前者在中细沉积物中出现的频率最高，而P. miliaris在粗沉积物中出现的频率更高。A. opercularis和S. laceratus随着时间推移表现出相似的出现反应，A. opercularis在粗沉积物下出现的频率更高。S. laceratus出现的频率随着沉积物逐渐变细而增加，而C. intestinalis无论沉积物粒度或深度如何，都不会从掩埋中出现。最后，也许并不令人惊讶的是，所有其他物种从掩埋中出现的最大能力来自浅埋（2厘米）。尽管如预期的那样，存活率一直高度依赖于掩埋的持续时间和深度，但出现行为并不那么容易预测，从而使预测变得复杂。我们得出结论，对掩埋的反应具有高度的物种特异性，因此对耐受性的一概而论可能过于简单化。这些数据可用于为环境影响模型提供信息，以便预测海床扰动的累积影响，并可为海床的可持续利用提供缓解措施。
