The contribution of benthic foraminifera to sediment bioturbation has widely been overlooked despite their huge abundance in intertidal soft sediments. In this preliminary study, we specifically chose to focus on two ...The contribution of benthic foraminifera to sediment bioturbation has widely been overlooked despite their huge abundance in intertidal soft sediments. In this preliminary study, we specifically chose to focus on two key species of benthic foraminifera in temperate intertidal mudflats, <span style="font-size:12px;font-family:Verdana;">Quinqueloculina seminula<span style="font-size:12px;font-family:Verdana;"> and <span style="font-size:12px;font-family:Verdana;">Ammonia <span style="font-size:12px;font-family:Verdana;">tepida<span style="font-size:12px;font-family:Verdana;">, and first experimentally investigated their individual movements at the sediment surface. We subsequently derived from these observations the individual-level surface sediment reworking rates, and used the actual abundance of these species to extrapolate these rates at the population level. Individual surface sediment reworking rates <span style="font-size:12px;font-family:Verdana;">SSRR<sub><span style="font-size:12px;font-family:Verdana;">i</sub><span style="font-size:12px;font-family:Verdana;"> ranged between 0.13 and 0.32 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;"><sup><span style="font-family:Verdana;"></sup><span style="font-size:12px;font-family:Verdana;">ind<span style="font-family:Verdana;font-size:8.33333px;"><sup>-1</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup> <span style="font-size:12px;font-family:Verdana;">for<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:12px;font-family:Verdana;">Q. seminula<span style="font-size:12px;font-family:Verdana;">, and between 0.12 and 0.28 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">ind<sup>-1</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">A. tepida<span style="font-size:12px;font-family:Verdana;">. Population-level surface sediment reworking rates were subsequently estimated as ranging between 11,484 and 28,710 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">m<sup>-2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">Q. seminula<span style="font-size:12px;font-family:Verdana;"> and 27,876 and 65,044 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">m<sup>-2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">A. tepida<span style="font-size:12px;font-family:Verdana;">. Noticeably, these reworking rates are comparable to, and eventually even higher than, the rates reported in the literature for populations of intertidal macro-invertebrates, such as the annelid polychaete <span style="font-size:12px;font-family:Verdana;">Melinna palmata<span style="font-size:12px;font-family:Verdana;"> and the bivalve <span style="font-size:12px;font-family:Verdana;">Abra <span style="font-size:12px;font-family:Verdana;">ovata<span style="font-size:12px;font-family:Verdana;">. Taken together these results suggest that despite their minute size intertidal benthic foraminifera are, thanks to their abundance, non-negligible contributors to the reworking of surface sediment, and may then play an unanticipated role in the benthic ecosystem functioning, through e.g. the enhancement of fluxes at the sediment-water interface.展开更多
通过2010年对江苏如东滩涂贝类养殖区表层沉积物中重金属Cu、Zn、Pb、Cd、Hg、As含量的调查分析,应用地质累积指数(index of geo-accumulation,Igeo)对各重金元素的污染状况进行了评价,结果表明重金属污染可分为3类:Cu、Cd、Hg为无污染...通过2010年对江苏如东滩涂贝类养殖区表层沉积物中重金属Cu、Zn、Pb、Cd、Hg、As含量的调查分析,应用地质累积指数(index of geo-accumulation,Igeo)对各重金元素的污染状况进行了评价,结果表明重金属污染可分为3类:Cu、Cd、Hg为无污染;Pb、As为中～无污染;Zn为中度污染,重金属污染程度顺序为Zn>As>Pb>Cd>Cu>Hg.根据沉积物质量基准(sediment quality guideline,SQG),表层沉积物中Cd、As的含量在各采样站位分别表现为无潜在生物毒性效应,偶尔有潜在生物毒性效应,Cu、Pb、Zn、Hg的含量则在部分采样站位偶尔有潜在生物毒性效应,其中仅有Zn在部分采样站位有频繁发生的潜在生物毒性效应.毒性单位评价(toxic unit,TU)结果表明,仅有1个采样站位具有明显的急性毒性,其余站位无急性生物毒性效应.主成分分析(principal component analysis,PCA)的结果表明,前2个主成分的贡献率分别为37.56%、33.71%,揭示了重金属污染主要有2个来源:工业点源排污和交通航运污染源.展开更多
文摘The contribution of benthic foraminifera to sediment bioturbation has widely been overlooked despite their huge abundance in intertidal soft sediments. In this preliminary study, we specifically chose to focus on two key species of benthic foraminifera in temperate intertidal mudflats, <span style="font-size:12px;font-family:Verdana;">Quinqueloculina seminula<span style="font-size:12px;font-family:Verdana;"> and <span style="font-size:12px;font-family:Verdana;">Ammonia <span style="font-size:12px;font-family:Verdana;">tepida<span style="font-size:12px;font-family:Verdana;">, and first experimentally investigated their individual movements at the sediment surface. We subsequently derived from these observations the individual-level surface sediment reworking rates, and used the actual abundance of these species to extrapolate these rates at the population level. Individual surface sediment reworking rates <span style="font-size:12px;font-family:Verdana;">SSRR<sub><span style="font-size:12px;font-family:Verdana;">i</sub><span style="font-size:12px;font-family:Verdana;"> ranged between 0.13 and 0.32 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;"><sup><span style="font-family:Verdana;"></sup><span style="font-size:12px;font-family:Verdana;">ind<span style="font-family:Verdana;font-size:8.33333px;"><sup>-1</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup> <span style="font-size:12px;font-family:Verdana;">for<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:12px;font-family:Verdana;">Q. seminula<span style="font-size:12px;font-family:Verdana;">, and between 0.12 and 0.28 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">ind<sup>-1</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">A. tepida<span style="font-size:12px;font-family:Verdana;">. Population-level surface sediment reworking rates were subsequently estimated as ranging between 11,484 and 28,710 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">m<sup>-2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">Q. seminula<span style="font-size:12px;font-family:Verdana;"> and 27,876 and 65,044 cm<sup>2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">m<sup>-2</sup><span style="white-space:nowrap;">·<span style="font-size:12px;font-family:Verdana;">day<sup>-1</sup><span style="font-size:12px;font-family:Verdana;"> for <span style="font-size:12px;font-family:Verdana;">A. tepida<span style="font-size:12px;font-family:Verdana;">. Noticeably, these reworking rates are comparable to, and eventually even higher than, the rates reported in the literature for populations of intertidal macro-invertebrates, such as the annelid polychaete <span style="font-size:12px;font-family:Verdana;">Melinna palmata<span style="font-size:12px;font-family:Verdana;"> and the bivalve <span style="font-size:12px;font-family:Verdana;">Abra <span style="font-size:12px;font-family:Verdana;">ovata<span style="font-size:12px;font-family:Verdana;">. Taken together these results suggest that despite their minute size intertidal benthic foraminifera are, thanks to their abundance, non-negligible contributors to the reworking of surface sediment, and may then play an unanticipated role in the benthic ecosystem functioning, through e.g. the enhancement of fluxes at the sediment-water interface.
