Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shenzhen Bay and are import...Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shenzhen Bay and are important 'refueling' point along the East Asian/Australian flyway of migratory birds. The environmental quality of Mai Po and Futian mudflats have aroused great concern due to rapid economic developments in Hong Kong and Shenzhen in recent decades. Macroinfauna of Mai Po and Futian mudflats was investigated in December 2000 and the faunal data were used to assess their environmental quality. Two other mudflats, namely Ma Wan Typhoon Shelter (a more disturbed area) and Luk Keng intertidal mudflat (a place with relatively less human disturbance), were also sampled for macroinfauna and used as reference mudflats. Shannon - Weaver species diversity index (Isd), biotic coefficient (Cb) and macrofaunal pollution index (Imp) of the macrofauna community on four intertidal mudflats were used to determine their environmental quality. The results showed that Luk Keng intertidal mudflat was unpolluted, Mai Po and Futian mudflats were slightly polluted, and Ma Wan was moderately polluted. The pollution in Ma Wan Typhoon Shelter mainly came from various types of rubbish and fishing boats that disturbed the sediment, while pollution sources in Mai Po and Futian mudflats were discharges of industrial water, municipal sewage and from nearby rivers.展开更多
Understanding of erosion and accretion patterns over intertidal mudflats during storm periods is vital for the management and sustainable development of coastal areas.This study aimed to investigate the effect of the ...Understanding of erosion and accretion patterns over intertidal mudflats during storm periods is vital for the management and sustainable development of coastal areas.This study aimed to investigate the effect of the 2014 storm Fung-wong on the erosion and accretion patterns of the Nanhui intertidal mudflats in the Yangtze estuary,China,based on field measurements and Delft3D numerical modeling.Results show that prolonged easterly winds during the storm enhance the flood velocity,weaken the ebb velocity,and even change the current direction.The current velocity,wave heights,and bed-level changes increased by 1-1.43 times,2.40-3.88 times,and 2.28-2.70 times than those of normal weather,respectively.The mudflats show a spatial pattern of overall erosion but increasing erosion magnitude from the high(landward)mudflat to the low(seaward)mudflat during the storm.The magnitude of bed-level change increases with increasing wind speed,but the spatial pattern of erosion and accretion remains the same.The main reason for this pattern is the longer submersion duration of the low mudflat compared with the high mudflat,so the hydrodynamic process is longer and stronger,leading to an enhancement in bed shear stress and sediment transport rate.Wind speed increases the hydrodynamic intensity but does not affect on the submersion duration over each part of the intertidal mudflat.This study is helpful to improve the understanding of physical processes during storms on intertidal mudflats and provides a reference for their protection,utilization,and management,as well as for research in related disciplines.展开更多
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
文摘Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shenzhen Bay and are important 'refueling' point along the East Asian/Australian flyway of migratory birds. The environmental quality of Mai Po and Futian mudflats have aroused great concern due to rapid economic developments in Hong Kong and Shenzhen in recent decades. Macroinfauna of Mai Po and Futian mudflats was investigated in December 2000 and the faunal data were used to assess their environmental quality. Two other mudflats, namely Ma Wan Typhoon Shelter (a more disturbed area) and Luk Keng intertidal mudflat (a place with relatively less human disturbance), were also sampled for macroinfauna and used as reference mudflats. Shannon - Weaver species diversity index (Isd), biotic coefficient (Cb) and macrofaunal pollution index (Imp) of the macrofauna community on four intertidal mudflats were used to determine their environmental quality. The results showed that Luk Keng intertidal mudflat was unpolluted, Mai Po and Futian mudflats were slightly polluted, and Ma Wan was moderately polluted. The pollution in Ma Wan Typhoon Shelter mainly came from various types of rubbish and fishing boats that disturbed the sediment, while pollution sources in Mai Po and Futian mudflats were discharges of industrial water, municipal sewage and from nearby rivers.
基金provided by the Natural Science Foundation of China(Grant number:42076170,42176164)the Key Laboratory of Coastal Salt Marsh Ecosystems and Resources,Ministry of Natural Resources(Grant number:KLCSMERMNR2021108)Jiangsu Special Program for Science and Technology Innovation(Grant number:JSZRHYKJ202106).
文摘Understanding of erosion and accretion patterns over intertidal mudflats during storm periods is vital for the management and sustainable development of coastal areas.This study aimed to investigate the effect of the 2014 storm Fung-wong on the erosion and accretion patterns of the Nanhui intertidal mudflats in the Yangtze estuary,China,based on field measurements and Delft3D numerical modeling.Results show that prolonged easterly winds during the storm enhance the flood velocity,weaken the ebb velocity,and even change the current direction.The current velocity,wave heights,and bed-level changes increased by 1-1.43 times,2.40-3.88 times,and 2.28-2.70 times than those of normal weather,respectively.The mudflats show a spatial pattern of overall erosion but increasing erosion magnitude from the high(landward)mudflat to the low(seaward)mudflat during the storm.The magnitude of bed-level change increases with increasing wind speed,but the spatial pattern of erosion and accretion remains the same.The main reason for this pattern is the longer submersion duration of the low mudflat compared with the high mudflat,so the hydrodynamic process is longer and stronger,leading to an enhancement in bed shear stress and sediment transport rate.Wind speed increases the hydrodynamic intensity but does not affect on the submersion duration over each part of the intertidal mudflat.This study is helpful to improve the understanding of physical processes during storms on intertidal mudflats and provides a reference for their protection,utilization,and management,as well as for research in related disciplines.
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.
